TY - JOUR AB - The concept of metabolic disruption through exposure to chemicals has expanded our understanding of how environmental pollution can contribute to metabolic dysregulation and, ultimately, diseases like obesity. New strategies for assessing the risks posed by chemicals are needed, and omics technologies, including proteomics, have proven to be powerful tools for investigating the molecular mechanisms of these metabolism-disrupting chemicals (MDCs). A potential MDC is the plasticizer DINCH─an alternative to legacy phthalates like DEHP, whose primary metabolite MINCH has been linked to the induction of adipogenesis and lipid accumulation. Here, global proteomics was complemented with insights into protein thermal stability and the profiles of post-translational modification (PTM) acetylation and phosphorylation to provide a profound understanding of chemical-induced metabolic disruption in adipocytes. We demonstrate the utility of advanced proteomics approaches in assessing the effects of potential MDCs by using the human SGBS adipocyte cell line. Adipose tissue PTM data from dietary DINCH-exposed mice were assessed as an in vivo model, and in vitro data shed light on DINCH's molecular effects, including protein interactions beyond its primary target PPARγ. The results emphasize the potential of omics approaches to enhance current risk assessment frameworks for emerging contaminants. AU - Aldehoff, A.S.* AU - Karkossa, I.* AU - Broghammer, H. AU - Krupka, S. AU - Weiner, J. AU - Goerdeler, C.* AU - Nuwayhid, R.* AU - Langer, S.* AU - Wabitsch, M.* AU - Rolle-Kampczyk, U.* AU - Klöting, N. AU - Blüher, M. AU - Heiker, J.T. AU - von Bergen, M.* AU - Schubert, K.* C1 - 75263 C2 - 57895 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 16774-16784 TI - Advanced proteomics approaches hold potential for the risk assessment of metabolism-disrupting chemicals as omics-based NAM: A case study using the phthalate substitute DINCH. JO - Environ. Sci. Technol. VL - 59 IS - 31 PB - Amer Chemical Soc PY - 2025 SN - 0013-936X ER - TY - JOUR AB - The development of new approach methodologies (NAMs) to replace current in vivo testing for the safety assessment of engineered nanomaterials (ENMs) is hindered by the scarcity of validated experimental data for many ENMs. We introduce a framework to address this challenge by harnessing the collective expertise of professionals from multiple complementary and related fields ("wisdom of crowds" or WoC). By integrating expert insights, we aim to fill data gaps and generate consensus concern scores for diverse ENMs, thereby enhancing the predictive power of nanosafety computational models. Our investigation reveals an alignment between expert opinion and experimental data, providing robust estimations of concern levels. Building upon these findings, we employ predictive machine learning models trained on the newly defined concern scores, ENM descriptors, and gene expression profiles, to quantify potential harm across various toxicity end points. These models further reveal key genes potentially involved in underlying toxicity mechanisms. Notably, genes associated with metal ion homeostasis, inflammation, and oxidative stress emerge as predictors of ENM toxicity across diverse end points. This study showcases the value of integrating expert knowledge and computational modeling to support more efficient, mechanism-informed, and scalable safety assessment of nanomaterials in the rapidly evolving landscape of nanotechnology. AU - Saarimäki, L.A.* AU - Fratello, M.* AU - Del Giudice, G.* AU - Di Lieto, E.* AU - Afantitis, A.* AU - Alenius, H.* AU - Chiavazzo, E.* AU - Gulumian, M.* AU - Karisola, P.* AU - Lynch, I.* AU - Mancardi, G.L.* AU - Melagraki, G.* AU - Netti, P.* AU - Papadiamantis, A.G.* AU - Peijnenburg, W.* AU - A Santos, H.* AU - Serchi, T.* AU - Shahbazi, M.A.* AU - Stöger, T. AU - Valsami-Jones, E.* AU - Vivo, P.* AU - Vinković Vrček, I.* AU - Vogel, U.* AU - Wick, P.* AU - Winkler, D.A.* AU - Serra, A.* AU - Greco, D.* C1 - 75157 C2 - 57814 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 14969-14980 TI - Wisdom of crowds for supporting the safety evaluation of nanomaterials. JO - Environ. Sci. Technol. VL - 59 IS - 29 PB - Amer Chemical Soc PY - 2025 SN - 0013-936X ER - TY - JOUR AB - In this study, we propose a novel long short-term memory (LSTM) neural network model that leverages color features (HSV: hue, saturation, value) extracted from street images to estimate air quality with particulate matter (PM) in four typical European environments: urban, suburban, villages, and the harbor. To evaluate its performance, we utilize concentration data for eight parameters of ambient PM (PM1.0, PM2.5, and PM10, particle number concentration, lung-deposited surface area, equivalent mass concentrations of ultraviolet PM, black carbon, and brown carbon) collected from a mobile monitoring platform during the nonheating season in downtown Augsburg, Germany, along with synchronized street view images. Experimental comparisons were conducted between the LSTM model and other deep learning models (recurrent neural network and gated recurrent unit). The results clearly demonstrate a better performance of the LSTM model compared with other statistically based models. The LSTM-HSV model achieved impressive interpretability rates above 80%, for the eight PM metrics mentioned above, indicating the expected performance of the proposed model. Moreover, the successful application of the LSTM-HSV model in other seasons of Augsburg city and various environments (suburbs, villages, and harbor cities) demonstrates its satisfactory generalization capabilities in both temporal and spatial dimensions. The successful application of the LSTM-HSV model underscores its potential as a versatile tool for the estimation of air pollution after presampling of the studied area, with broad implications for urban planning and public health initiatives. AU - Liu, X.* AU - Zhang, X.* AU - Wang, R.* AU - Liu, Y.* AU - Hadiatullah, H.* AU - Xu, Y.* AU - Wang, T.* AU - Bendl, J.* AU - Adam, T. AU - Schnelle-Kreis, J. AU - Querol, X.* C1 - 69983 C2 - 55349 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 3869-3882 TI - High-precision microscale particulate matter prediction in diverse environments using a long short-term memory neural network and street view imagery. JO - Environ. Sci. Technol. VL - 58 IS - 8 PB - Amer Chemical Soc PY - 2024 SN - 0013-936X ER - TY - JOUR AB - Socioeconomic inequalities in the exposome have been found to be complex and highly context-specific, but studies have not been conducted in large population-wide cohorts from multiple countries. This study aims to examine the external exposome, encompassing individual and environmental factors influencing health over the life course, and to perform dimension reduction to derive interpretable characterization of the external exposome for multicountry epidemiological studies. Analyzing data from over 25 million individuals across seven European countries including 12 administrative and traditional cohorts, we utilized domain-specific principal component analysis (PCA) to define the external exposome, focusing on air pollution, the built environment, and air temperature. We conducted linear regression to estimate the association between individual- and area-level socioeconomic position and each domain of the external exposome. Consistent exposure patterns were observed within countries, indicating the representativeness of traditional cohorts for air pollution and the built environment. However, cohorts with limited geographical coverage and Southern European countries displayed lower temperature variability, especially in the cold season, compared to Northern European countries and cohorts including a wide range of urban and rural areas. The individual- and area-level socioeconomic determinants (i.e., education, income, and unemployment rate) of the urban exposome exhibited significant variability across the European region, with area-level indicators showing stronger associations than individual variables. While the PCA approach facilitated common interpretations of the external exposome for air pollution and the built environment, it was less effective for air temperature. The diverse socioeconomic determinants suggest regional variations in environmental health inequities, emphasizing the need for targeted interventions across European countries. AU - Saucy, A.* AU - Coloma, F.* AU - Olmos, S.* AU - Åström, C.* AU - Blay, N.* AU - Boer, J.M.A.* AU - Dadvand, P.* AU - de Bont, J.* AU - de Cid, R.* AU - de Hoogh, K.* AU - Dimakopoulou, K.* AU - Gehring, U.* AU - Huss, A.* AU - Ibi, D.* AU - Katsouyanni, K.* AU - Koppelman, G.* AU - Ljungman, P.* AU - Melén, E.* AU - Nieuwenhuijsen, M.* AU - Nobile, F.* AU - Peters, A. AU - Pickford, R. AU - Vermeulen, R.* AU - Vienneau, D.* AU - Vlaanderen, J.* AU - Wolf, K. AU - Yu, Z.* AU - Samoli, E.* AU - Stafoggia, M.* AU - Tonne, C.* C1 - 71638 C2 - 56327 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 16248-16257 TI - Socioeconomic inequalities in the external exposome in European cohorts: The EXPANSE Project. JO - Environ. Sci. Technol. VL - 58 IS - 37 PB - Amer Chemical Soc PY - 2024 SN - 0013-936X ER - TY - JOUR AB - Long-term exposure to traffic-related air pollution (TRAP) is associated with cardiometabolic disease; however, its role in subclinical stages of disease development is unclear. Thus, we aimed to explore this association in a cross-sectional analysis, with cardiometabolic phenotypes derived from magnetic resonance imaging (MRI). Phenotypes of the left (LV) and right cardiac ventricle, whole-body adipose tissue (AT), and organ-specific AT were obtained by MRI in 400 participants of the KORA cohort. Land-use regression models were used to estimate residential long-term exposures to TRAP, e.g., nitrogen dioxides (NO2) or particle number concentration (PNC). Associations between TRAP and MRI phenotypes were modeled using linear regression. Participants' mean age was 56 ± 9 years, and 42% were female. Long-term exposure to TRAP was associated with decreased LV wall thickness; a 6.0 μg/m3 increase in NO2 was associated with a -1.9% [95% confidence interval: -3.7%; -0.1%] decrease in mean global LV wall thickness. Furthermore, we found associations between TRAP and increased cardiac AT. A 2,242 n/cm3 increase in PNC was associated with a 4.3% [-1.7%; 10.4%] increase in mean total cardiac AT. Associations were more pronounced in women and in participants with diabetes. Our exploratory study indicates that long-term exposure to TRAP is associated with subclinical cardiometabolic disease states, particularly in metabolically vulnerable subgroups. AU - Woeckel, M. AU - Rospleszcz, S. AU - Wolf, K. AU - Breitner-Busch, S. AU - Ingrisch, M.* AU - Bamberg, F.* AU - Ricke, J.* AU - Schlett, C.L.* AU - Storz, C.* AU - Schneider, A.E. AU - Stoecklein, S.* AU - Peters, A. C1 - 71907 C2 - 56496 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 18064-18075 TI - Association between long-term exposure to traffic-related air pollution and cardio-metabolic phenotypes: An MRI data-based analysis. JO - Environ. Sci. Technol. VL - 58 IS - 41 PB - Amer Chemical Soc PY - 2024 SN - 0013-936X ER - TY - JOUR AB - The updated climate models provide projections at a fine scale, allowing us to estimate health risks due to future warming after accounting for spatial heterogeneity. Here, we utilized an ensemble of high-resolution (25 km) climate simulations and nationwide mortality data from 306 Chinese cities to estimate death anomalies attributable to future warming. Historical estimation (1986-2014) reveals that about 15.5% [95% empirical confidence interval (eCI):13.1%, 17.6%] of deaths are attributable to nonoptimal temperature, of which heat and cold corresponded to attributable fractions of 4.1% (eCI:2.4%, 5.5%) and 11.4% (eCI:10.7%, 12.1%), respectively. Under three climate scenarios (SSP126, SSP245, and SSP585), the national average temperature was projected to increase by 1.45, 2.57, and 4.98 °C by the 2090s, respectively. The corresponding mortality fractions attributable to heat would be 6.5% (eCI:5.2%, 7.7%), 7.9% (eCI:6.3%, 9.4%), and 11.4% (eCI:9.2%, 13.3%). More than half of the attributable deaths due to future warming would occur in north China and cardiovascular mortality would increase more drastically than respiratory mortality. Our study shows that the increased heat-attributable mortality burden would outweigh the decreased cold-attributable burden even under a moderate climate change scenario across China. The results are helpful for national or local policymakers to better address the challenges of future warming. AU - Yin, P.* AU - He, C. AU - Chen, R.* AU - Huang, J.* AU - Luo, Y.* AU - Gao, X.* AU - Xu, Y.* AU - Ji, J.S.* AU - Cai, W.* AU - Wei, Y.* AU - Li, H.* AU - Zhou, M.* AU - Kan, H.* C1 - 70365 C2 - 55533 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 6226–6235 TI - Projection of mortality burden attributable to nonoptimum temperature with high spatial resolution in China. JO - Environ. Sci. Technol. VL - 58 IS - 14 PB - Amer Chemical Soc PY - 2024 SN - 0013-936X ER - TY - JOUR AB - Effective density (ρeff) is an important property describing particle transportation in the atmosphere and in the human respiratory tract. In this study, the particle size dependency of ρeff was determined for fresh and photochemically aged particles from residential combustion of wood logs and brown coal, as well as from an aerosol standard (CAST) burner. ρeff increased considerably due to photochemical aging, especially for soot agglomerates larger than 100 nm in mobility diameter. The increase depends on the presence of condensable vapors and agglomerate size and can be explained by collapsing of chain-like agglomerates and filling of their voids and formation of secondary coating. The measured and modeled particle optical properties suggest that while light absorption, scattering, and the single-scattering albedo of soot particle increase during photochemical processing, their radiative forcing remains positive until the amount of nonabsorbing coating exceeds approximately 90% of the particle mass. AU - Leskinen, J.* AU - Hartikainen, A.* AU - Väätäinen, S.* AU - Ihalainen, M.* AU - Virkkula, A.* AU - Mesceriakovas, A.* AU - Tiitta, P.* AU - Miettinen, M.* AU - Lamberg, H.* AU - Czech, H. AU - Yli-Pirilä, P.* AU - Tissari, J.* AU - Jakobi, G. AU - Zimmermann, R. AU - Sippula, O.* C1 - 67704 C2 - 54011 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 5137-5148 TI - Photochemical aging induces changes in the effective densities, morphologies, and optical pof combustion aerosol particles. JO - Environ. Sci. Technol. VL - 57 IS - 13 PB - Amer Chemical Soc PY - 2023 SN - 0013-936X ER - TY - JOUR AB - Residential heating with solid fuels is one of the major drivers for poor air quality in Central and Eastern Europe, and coal is still one of the major fuels in countries, such as Poland, the Czech Republic, and Hungary. In this work, emissions from a single-room heater fueled with brown coal briquettes (BCBs) and spruce logs (SLs) were analyzed for signatures of inorganic as well as semivolatile aromatic and low-volatile organic constituents. High variations in organic carbon (OC) emissions of BCB emissions, ranging from 5 to 22 mg MJ-1, were associated to variations in carbon monoxide (CO) emissions, ranging from 900 to 1900 mg MJ-1. Residential BCB combustion turned out to be an equally important source of levoglucosan, an established biomass burning marker, as spruce logwood combustion, but showed distinct higher ratios to manosan and galactosan. Signatures of polycyclic aromatic hydrocarbons emitted by BCB combustion exhibited defunctionalization and desubstitution with increasing combustion quality. Lastly, the concept of island and archipelago structural motifs adapted from petroleomics is used to describe the fraction low-volatile organic compounds in particulate emissions, where a transition from archipelago to island motifs in relation with decreasing CO emissions was observed in BCB emissions, while emissions from SL combustion exhibited the island motif. AU - Martens, P.* AU - Czech, H. AU - Orasche, J. AU - Abbaszade, G. AU - Sklorz, M. AU - Michalke, B. AU - Tissari, J.* AU - Bizjak, T.* AU - Ihalainen, M.* AU - Suhonen, H.* AU - Yli-Pirilä, P.* AU - Jokiniemi, J.* AU - Sippula, O.* AU - Zimmermann, R. C1 - 67657 C2 - 53964 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 5532-5543 TI - Brown coal and logwood combustion in a modern heating appliance: The impact of combustion quality and fuel on organic aerosol composition. JO - Environ. Sci. Technol. VL - 57 IS - 14 PB - Amer Chemical Soc PY - 2023 SN - 0013-936X ER - TY - JOUR AB - Increasing evidence has revealed that exposure to low temperatures is linked to a higher risk of chronic diseases and death; however, the mechanisms underlying the observed associations are still poorly understood. We performed a cross-sectional analysis with 1115 participants from the population-based KORA F4 study, which was conducted in Augsburg, Germany, from 2006 to 2008. Seventy-one inflammation-related protein biomarkers were analyzed in serum using proximity extension assay technology. We employed generalized additive models to explore short- and medium-term effects of air temperature on biomarkers of subclinical inflammation at cumulative lags of 0-1 days, 2-6 days, 0-13 days, 0-27 days, and 0-55 days. We found that short- and medium-term exposures to lower air temperature were associated with higher levels in 64 biomarkers of subclinical inflammation, such as Protein S100-A12 (EN-RAGE), Interleukin-6 (IL-6), Interleukin-10 (IL-10), C-C motif chemokine 28 (CCL28), and Neurotrophin-3 (NT-3). More pronounced associations between lower air temperature and higher biomarker of subclinical inflammation were observed among older participants, people with cardiovascular disease or prediabetes/diabetes, and people exposed to higher levels of air pollution (PM2.5, NO2, and O3). Our findings provide intriguing insight into how low air temperature may cause adverse health effects by activating inflammatory pathways. AU - Ni, W. AU - Breitner-Busch, S. AU - Nikolaou, N. AU - Wolf, K. AU - Zhang, S. AU - Peters, A. AU - Herder, C.* AU - Schneider, A.E. C1 - 68019 C2 - 54497 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 12210-12221 TI - Effects of short- and medium-term exposures to lower air temperature on 71 novel biomarkers of subclinical inflammation: Results from the KORA F4 Study. JO - Environ. Sci. Technol. VL - 57 IS - 33 PB - Amer Chemical Soc PY - 2023 SN - 0013-936X ER - TY - JOUR AB - Humic-like substances (HULIS), known for their substantial impact on the atmosphere, are identified in marine diesel engine emissions obtained from five different fuels at two engine loads simulating real world scenarios as well as the application of wet sulfur scrubbers. The HULIS chemical composition is characterized by electrospray ionization (ESI) ultrahigh resolution mass spectrometry and shown to contain partially oxidized alkylated polycyclic aromatic compounds as well as partially oxidized aliphatic compounds, both including abundant nitrogen- and sulfur-containing species, and clearly different to HULIS emitted from biomass burning. Fuel properties such as sulfur content and aromaticity as well as the fuel combustion efficiency and engine mode are reflected in the observed HULIS composition. When the marine diesel engine is operated below the optimum engine settings, e.g., during maneuvering in harbors, HULIS-C emission factors are increased (262-893 mg kg-1), and a higher number of HULIS with a shift toward lower degree of oxidation and higher aromaticity is detected. Additionally, more aromatic and aliphatic CHOS compounds in HULIS were detected, especially for high-sulfur fuel combustion. The application of wet sulfur scrubbers decreased the HULIS-C emission factors by 4-49% but also led to the formation of new HULIS compounds. Overall, our results suggest the consideration of marine diesel engines as a relevant regional source of HULIS emissions. AU - Schneider, E.* AU - Czech, H. AU - Hansen, H.J.* AU - Jeong, S. AU - Bendl, J.* AU - Saraji-Bozorgzad, M.R.* AU - Sklorz, M. AU - Etzien, U.* AU - Buchholz, B.* AU - Streibel, T. AU - Adam, T. AU - Rüger, C.P.* AU - Zimmermann, R. C1 - 68259 C2 - 54736 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 13948-13958 TI - Humic-like substances (HULIS) in ship engine emissions: Molecular composition effected by fuel type, engine mode, and wet scrubber usage. JO - Environ. Sci. Technol. VL - 57 IS - 37 PB - Amer Chemical Soc PY - 2023 SN - 0013-936X ER - TY - JOUR AB - We assessed mortality risks associated with source-specific fine particles (PM2.5) in a pooled European cohort of 323,782 participants. Cox proportional hazard models were applied to estimate mortality hazard ratios (HRs) for source-specific PM2.5 identified through a source apportionment analysis. Exposure to 2010 annual average concentrations of source-specific PM2.5 components was assessed at baseline residential addresses. The source apportionment resulted in the identification of five sources: traffic, residual oil combustion, soil, biomass and agriculture, and industry. In single-source analysis, all identified sources were significantly positively associated with increased natural mortality risks. In multisource analysis, associations with all sources attenuated but remained statistically significant with traffic, oil, and biomass and agriculture. The highest association per interquartile increase was observed for the traffic component (HR: 1.06; 95% CI: 1.04 and 1.08 per 2.86 μg/m3 increase) across five identified sources. On a 1 μg/m3 basis, the residual oil-related PM2.5 had the strongest association (HR: 1.13; 95% CI: 1.05 and 1.22), which was substantially higher than that for generic PM2.5 mass, suggesting that past estimates using the generic PM2.5 exposure response function have underestimated the potential clean air health benefits of reducing fossil-fuel combustion. Source-specific associations with cause-specific mortality were in general consistent with findings of natural mortality. AU - Chen, J.* AU - Hoek, G.* AU - de Hoogh, K.* AU - Rodopoulou, S.* AU - Andersen, Z.J.* AU - Bellander, T.* AU - Brandt, J.* AU - Fecht, D.* AU - Forastiere, F.* AU - Gulliver, J.* AU - Hertel, O.* AU - Hoffmann, B.* AU - Hvidtfeldt, U.A.* AU - Verschuren, W.M.M.* AU - Jöckel, K.H.* AU - Jørgensen, J.T.* AU - Katsouyanni, K.* AU - Ketzel, M.* AU - Méndez, D.Y.* AU - Leander, K.* AU - Liu, S.* AU - Ljungman, P.* AU - Faure, E.* AU - Magnusson, P.K.E.* AU - Nagel, G.* AU - Pershagen, G.* AU - Peters, A. AU - Raaschou-Nielsen, O.* AU - Rizzuto, D.* AU - Samoli, E.* AU - van der Schouw, Y.T.* AU - Schramm, S.* AU - Severi, G.* AU - Stafoggia, M.* AU - Strak, M.* AU - Sørensen, M.* AU - Tjønneland, A.* AU - Weinmayr, G.* AU - Wolf, K. AU - Zitt, E.* AU - Brunekreef, B.* AU - Thurston, G.D.* C1 - 65535 C2 - 52324 SP - 9277–9290 TI - Long-term exposure to source-specific fine particles and mortality – a pooled analysis of 14 European cohorts within the ELAPSE project. JO - Environ. Sci. Technol. VL - 56 IS - 13 PY - 2022 SN - 0013-936X ER - TY - JOUR AB - Slow microbial degradation of organic trace chemicals ("micropollutants") has been attributed to either downregulation of enzymatic turnover or rate-limiting substrate supply at low concentrations. In previous biodegradation studies, a drastic decrease in isotope fractionation of atrazine revealed a transition from rate-limiting enzyme turnover to membrane permeation as a bottleneck when concentrations fell below the Monod constant of microbial growth. With degradation of the pollutant 4-chlorophenol (4-CP) by Arthrobacter chlorophenolicus A6, this study targeted a bacterium which adapts its enzyme activity to concentrations. Unlike with atrazine degradation, isotope fractionation of 4-CP increased at lower concentrations, from ε(C) = -1.0 ± 0.5‰ in chemostats (D = 0.090 h-1, 88 mg L-1) and ε(C) = -2.1 ± 0.5‰ in batch (c0 = 220 mg L-1) to ε(C) = -4.1 ± 0.2‰ in chemostats at 90 μg L-1. Surprisingly, fatty acid composition indicated increased cell wall permeability at high concentrations, while proteomics revealed that catabolic enzymes (CphCI and CphCII) were differentially expressed at D = 0.090 h-1. These observations support regulation on the enzyme activity level─through either a metabolic shift between catabolic pathways or decreased enzymatic turnover at low concentrations─and, hence, reveal an alternative end-member scenario for bacterial adaptation at low concentrations. Including more degrader strains into this multidisciplinary analytical approach offers the perspective to build a knowledge base on bottlenecks of bioremediation at low concentrations that considers bacterial adaptation. AU - Kundu, K. AU - Melsbach, A. AU - Heckel, B. AU - Schneidemann, S. AU - Kanapathi, D. AU - Marozava, S. AU - Merl-Pham, J. AU - Elsner, M. C1 - 64377 C2 - 51967 SP - 3021-3032 TI - Linking increased isotope fractionation at low concentrations to enzyme activity regulation: 4-Cl phenol degradation by Arthrobacter chlorophenolicus A6. JO - Environ. Sci. Technol. VL - 56 IS - 5 PY - 2022 SN - 0013-936X ER - TY - JOUR AB - Higher air temperature is associated with increased age-related morbidity and mortality. To date, short-term effects of air temperature on leukocyte telomere length have not been investigated in an adult population. We aimed to examine the short-term associations between air temperature and leukocyte telomere length in an adult population-based setting, including two independent cohorts. This population-based study involved 5864 participants from the KORA F3 (2004-2005) and F4 (2006-2008) cohort studies conducted in Augsburg, Germany. Leukocyte telomere length was assessed by a quantitative PCR-based method. We estimated air temperature at each participant's residential address through a highly resolved spatiotemporal model. We conducted cohort-specific generalized additive models to explore the short-term effects of air temperature on leukocyte telomere length at lags 0-1, 2-6, 0-6, and 0-13 days separately and pooled the estimates by fixed-effects meta-analysis. Our study found that between individuals, an interquartile range (IQR) increase in daily air temperature was associated with shorter leukocyte telomere length at lags 0-1, 2-6, 0-6, and 0-13 days (%change: -2.96 [-4.46; -1.43], -2.79 [-4.49; -1.07], -4.18 [-6.08; -2.25], and -6.69 [-9.04; -4.27], respectively). This meta-analysis of two cohort studies showed that between individuals, higher daily air temperature was associated with shorter leukocyte telomere length. AU - Ni, W. AU - Wolf, K. AU - Breitner-Busch, S. AU - Zhang, S. AU - Nikolaou, N. AU - Ward-Caviness, C.K.* AU - Waldenberger, M. AU - Gieger, C. AU - Peters, A. AU - Schneider, A.E. C1 - 66851 C2 - 53322 SP - 17815-17824 TI - Higher daily air temperature is associated with shorter leukocyte telomere length: KORA F3 and KORA F4. JO - Environ. Sci. Technol. VL - 56 IS - 24 PY - 2022 SN - 0013-936X ER - TY - JOUR AB - Compound-specific isotope analysis (CSIA) can reveal mass-transfer limitations during biodegradation of organic pollutants by enabling the detection of masked isotope fractionation. Here, we applied CSIA to monitor the adaptive response of bacterial degradation in inoculated sediment to low contaminant concentrations over time. We characterized Aminobacter sp. MSH1 activity in a flow-through sediment tank in response to a transient supply of elevated 2,6-dichlorobenzamide (BAM) concentrations as a priming strategy and took advantage of an inadvertent intermittence to investigate the effect of short-term flow fluctuations. Priming and flow fluctuations yielded improved biodegradation performance and increased biodegradation capacity, as evaluated from bacterial activity and residual concentration time series. However, changes in isotope ratios in space and over time evidenced that mass transfer became increasingly limiting for degradation of BAM at low concentrations under such stimulated conditions, and that activity decreased further due to bacterial adaptation at low BAM (μg/L) levels. Isotope ratios, in conjunction with residual substrate concentrations, therefore helped identifying underlying limitations of biodegradation in such a stimulated system, offering important insight for future optimization of remediation schemes. AU - Sun, F. AU - Mellage, A.* AU - Wang, Z. AU - Bakkour, R.* AU - Griebler, C.* AU - Thullner, M.* AU - Cirpka, O.A.* AU - Elsner, M. C1 - 64655 C2 - 51971 SP - 4050–4061 TI - Toward improved bioremediation strategies: Response of BAM-degradation activity to concentration and flow changes in an inoculated bench-scale sediment tank. JO - Environ. Sci. Technol. VL - 56 IS - 7 PY - 2022 SN - 0013-936X ER - TY - JOUR AB - Microbial reduction of Fe(III) minerals is a prominent process in redoximorphic soils and is strongly affected by organic matter (OM). We herein determined the rate and extent of microbial reduction of ferrihydrite (Fh) with either adsorbed or coprecipitated OM by Geobacter sulfurreducens. We focused on OM-mediated effects on electron uptake and alterations in Fh crystallinity. The OM was obtained from anoxic soil columns (effluent OM, efOM) and included-unlike water-extractable OM-compounds released by microbial activity under anoxic conditions. We found that organic molecules in efOM had generally no or only very low electron-accepting capacity and were incorporated into the Fh aggregates when coprecipitated with Fh. Compared to OM-free Fh, adsorption of efOM to Fh decelerated the microbial Fe(III) reduction by passivating the Fh surface toward electron uptake. In contrast, coprecipitation of Fh with efOM accelerated the microbial reduction, likely because efOM disrupted the Fh structure, as noted by Mössbauer spectroscopy. Additionally, the adsorbed and coprecipitated efOM resulted in a more sustained Fe(III) reduction, potentially because efOM could have effectively scavenged biogenic Fe(II) and prevented the passivation of the Fh surface by the adsorbed Fe(II). Fe(III)-OM coprecipitates forming at anoxic-oxic interfaces are thus likely readily reducible by Fe(III)-reducing bacteria in redoximorphic soils. AU - Fritzsche, A.* AU - Bosch, J. AU - Sander, M.* AU - Schröder, C.* AU - Byrne, J.M.* AU - Ritschel, T.* AU - Joshi, P.* AU - Maisch, M.* AU - Meckenstock, R.U. AU - Kappler, A.* AU - Totsche, K.U.* C1 - 62646 C2 - 51017 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 10821-10831 TI - Organic matter from redoximorphic soils accelerates and sustains microbial Fe(III) reduction. JO - Environ. Sci. Technol. VL - 55 IS - 15 PB - Amer Chemical Soc PY - 2021 SN - 0013-936X ER - TY - JOUR AB - The study investigates the spatial pattern of black carbon (BC) at a high spatial resolution in Augsburg, Germany. Sixty two walks were performed to assess the concentrations of equivalent black carbon (eBC), ultraviolet particulate matter (UVPM), and equivalent brown carbon (eBrC) in different seasons and at different times of the day with a mobile platform (i.e., trolley). Along with BC measurements, images of street microenvironments were recorded. Meteorological parameters, including temperature, relative humidity, and wind speed, were monitored. The BC concentrations showed significant spatial heterogeneity and diurnal variations peaking in the morning and at night. The highest BC concentrations were observed near dense traffic. The correlations between BC and street views (buildings, roads, cars, and vegetation) were weak but highly significant. Moreover, meteorological factors also influenced the BC concentration. A model based on street view images and meteorological data was developed to examine the driving factors of the spatial variability of BC concentrations at a higher spatial resolution as different microenvironments based on traffic density. The best results were obtained for UVPM and eBC (71 and 70% explained variability). eBrC (53%), to which other sources besides road traffic can also make significant contributions, is modeled less well. AU - Liu, X. AU - Zhang, X.* AU - Schnelle-Kreis, J. AU - Jakobi, G. AU - Cao, X. AU - Cyrys, J. AU - Yang, L.* AU - Schloter-Hai, B. AU - Abbaszade, G. AU - Orasche, J. AU - Khedr, M. AU - Kowalski, M. AU - Hank, M.* AU - Zimmermann, R. C1 - 60772 C2 - 49529 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 160-168 TI - Spatiotemporal characteristics and driving factors of black carbon iv Augsburg, Germany: Combination of mobile monitoring and street view images. JO - Environ. Sci. Technol. VL - 55 IS - 1 PB - Amer Chemical Soc PY - 2021 SN - 0013-936X ER - TY - JOUR AB - Organic contaminant degradation by suspended bacteria in chemostats has shown that isotope fractionation decreases dramatically when pollutant concentrations fall below the (half-saturation) Monod constant. This masked isotope fractionation implies that membrane transfer is slow relative to the enzyme turnover at μg L-1 substrate levels. Analogous evidence of mass transfer as a bottleneck for biodegradation in aquifer settings, where microbes are attached to the sediment, is lacking. A quasi-two-dimensional flow-through sediment microcosm/tank system enabled us to study the aerobic degradation of 2,6-dichlorobenzamide (BAM), while collecting sufficient samples at the outlet for compound-specific isotope analysis. By feeding an anoxic BAM solution through the center inlet port and dissolved oxygen (DO) above and below, strong transverse concentration cross-gradients of BAM and DO yielded zones of low (μg L-1) steady-state concentrations. We were able to simulate the profiles of concentrations and isotope ratios of the contaminant plume using a reactive transport model that accounted for a mass-transfer limitation into bacterial cells, where apparent isotope enrichment factors *ε decreased strongly below concentrations around 600 μg/L BAM. For the biodegradation of organic micropollutants, mass transfer into the cell emerges as a bottleneck, specifically at low (μg L-1) concentrations. Neglecting this effect when interpreting isotope ratios at field sites may lead to a significant underestimation of biodegradation. AU - Sun, F. AU - Mellage, A.* AU - Gharasoo, M. AU - Melsbach, A. AU - Cao, X. AU - Zimmermann, R. AU - Griebler, C.* AU - Thullner, M.* AU - Cirpka, O.A.* AU - Elsner, M. C1 - 62042 C2 - 50608 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 7386-7397 TI - Mass-transfer-limited biodegradation at low concentrations-evidence from reactive transport modeling of isotope profiles in a bench-scale aquifer. JO - Environ. Sci. Technol. VL - 55 IS - 11 PB - Amer Chemical Soc PY - 2021 SN - 0013-936X ER - TY - JOUR AB - Determining whether aqueous diffusion and dispersion lead to significant isotope fractionation is important for interpreting the isotope ratios of organic contaminants in groundwater. We performed diffusion experiments with modified Stokes diaphragm cells and transverse-dispersion experiments in quasi-two-dimensional flow-through sediment tank systems to explore isotope fractionation for benzene, toluene, ethylbenzene, 2,6-dichlorobenzamide, and metolachlor at natural isotopic abundance. We observed very small to negligible diffusion- and transverse-dispersion-induced isotope enrichment factors (ε < -0.4 ‰), with changes in carbon and nitrogen isotope values within ±0.5‰ and ±1‰, respectively. Isotope effects of diffusion did not show a clear correlation with isotopologue mass with calculated power-law exponents β close to zero (0.007 < β < 0.1). In comparison to ions, noble gases, and labeled compounds, three aspects stand out. (i) If a mass dependence is derived from collision theory, then isotopologue masses of polyatomic molecules would be affected by isotopes of multiple elements resulting in very small expected effects. (ii) However, collisions do not necessarily lead to translational movement but can excite molecular vibrations or rotations minimizing the mass dependence. (iii) Solute-solvent interactions like H-bonds can further minimize the effect of collisions. Modeling scenarios showed that an inadequate model choice, or erroneous choice of β, can greatly overestimate the isotope fractionation by diffusion and, consequently, transverse dispersion. In contrast, available data for chlorinated solvent and gasoline contaminants at natural isotopic abundance suggest that in field scenarios, a potential additional uncertainty from aqueous diffusion or dispersion would add to current instrumental uncertainties on carbon or nitrogen isotope values (±1‰) with an additional ±1‰ at most. AU - Sun, F. AU - Peters, J. AU - Thullner, M.* AU - Cirpka, O.A.* AU - Elsner, M. C1 - 61708 C2 - 50405 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 4772-4782 TI - Magnitude of diffusion- and transverse dispersion-induced isotope fractionation of organic compounds in aqueous systems. JO - Environ. Sci. Technol. VL - 55 IS - 8 PB - Amer Chemical Soc PY - 2021 SN - 0013-936X ER - TY - JOUR AB - Multielement isotope fractionation studies to assess pollutant transformation are well-established for point-source pollution but are only emerging for diffuse pollution by micropollutants like pesticides. Specifically, chlorine isotope fractionation is hardly explored but promising, because many pesticides contain only few chlorine atoms so that "undiluted" position-specific Cl isotope effects can be expected in compound-average data. This study explored combined Cl, N, and C isotope fractionation to sensitively detect biotic and abiotic transformation of the widespread herbicides and groundwater contaminants acetochlor, metolachlor, and atrazine. For chloroacetanilides, abiotic hydrolysis pathways studied under acidic, neutral, and alkaline conditions as well as biodegradation in two soils resulted in pronounced Cl isotope fractionation (εCl from -5.0 ± 2.3 to -6.5 ± 0.7‰). The characteristic dual C-Cl isotope fractionation patterns (ΛC-Cl from 0.39 ± 0.15 to 0.67 ± 0.08) reveal that Cl isotope analysis provides a robust indicator of chloroacetanilide degradation. For atrazine, distinct ΛC-Cl values were observed for abiotic hydrolysis (7.4 ± 1.9) compared to previous reports for biotic hydrolysis and oxidative dealkylation (1.7 ± 0.9 and 0.6 ± 0.1, respectively). The 3D isotope approach allowed differentiating transformations that would not be distinguishable based on C and N isotope data alone. This first data set on Cl isotope fractionation in chloroacetanilides, together with new data in atrazine degradation, highlights the potential of using compound-specific chlorine isotope analysis for studying in situ pesticide degradation. AU - Torrentó, C.* AU - Ponsin, V.* AU - Lihl, C. AU - Hofstetter, T.B.* AU - Baran, N.* AU - Elsner, M. AU - Hunkeler, D.* C1 - 63194 C2 - 51380 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 13891-13901 TI - Triple-element compound-specific stable isotope analysis (3D-CSIA): Added value of Cl isotope ratios to assess herbicide degradation. JO - Environ. Sci. Technol. VL - 55 IS - 20 PB - Amer Chemical Soc PY - 2021 SN - 0013-936X ER - TY - JOUR AB - We developed Europe-wide models of long-term exposure to eight elements (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) in particulate matter with diameter <2.5 mu m (PM2.5) using standardized measurements for one-year periods between October 2008 and April 2011 in 19 study areas across Europe, with supervised linear regression (SLR) and random forest (RF) algorithms. Potential predictor variables were obtained from satellites, chemical transport models, land-use, traffic, and industrial point source databases to represent different sources. Overall model performance across Europe was moderate to good for all elements with hold-out-validation R-squared ranging from 0.41 to 0.90. RF consistently outperformed SLR. Models explained within-area variation much less than the overall variation, with similar performance for RF and SLR. Maps proved a useful additional model evaluation tool. Models differed substantially between elements regarding major predictor variables, broadly reflecting known sources. Agreement between the two algorithm predictions was generally high at the overall European level and varied substantially at the national level. Applying the two models in epidemiological studies could lead to different associations with health. If both between- and within-area exposure variability are exploited, RF may be preferred. If only within-area variability is used, both methods should be interpreted equally. AU - Chen, J.* AU - de Hoogh, K.* AU - Gulliver, J.* AU - Hoffmann, B.* AU - Hertel, O.* AU - Ketzel, M.* AU - Weinmayr, G.* AU - Bauwelinck, M.* AU - van Donkelaar, A.* AU - Hvidtfeldt, U.A.* AU - Atkinson, R.* AU - Janssen, N.A.H.* AU - Martin, R.V.* AU - Samoli, E.* AU - Andersen, Z.J.* AU - Oftedal, B.* AU - Stafoggia, M.* AU - Strak, M.* AU - Wolf, K. AU - Vienneau, D.* AU - Brunekreef, B.* AU - Hoek, G.* C1 - 61121 C2 - 49609 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 15698-15709 TI - Development of Europe-wide models for particle elemental composition using supervised linear regression and random forest. JO - Environ. Sci. Technol. VL - 54 IS - 24 PB - Amer Chemical Soc PY - 2020 SN - 0013-936X ER - TY - JOUR AB - Atmospheric brown carbon (BrC) is an important contributor to the radiative forcing of climate by organic aerosols. Because of the molecular diversity of BrC compounds and their dynamic transformations, it is challenging to predictively understand BrC optical properties. OH radical and O-3 reactions, together with photolysis, lead to diminished light absorption and lower warming effects of biomass burning BrC. The effects of night-time aging on the optical properties of BrC aerosols are less known. To address this knowledge gap, night-time NO3 radical chemistry with tar aerosols from wood pyrolysis was investigated in a flow reactor. This study shows that the optical properties of BrC change because of transformations driven by reactions with the NO3 radical that form new absorbing species and lead to significant absorption enhancement over the ultraviolet-visible (UV-vis) range. The overnight aging increases the mass absorption coefficients of the BrC by a factor of 1.3-3.2 between 380 nm and 650 nm. Nitrated organic compounds, particularly nitroaromatics, were identified as the main products that contribute to the enhanced light absorption in the secondary BrC. Night-time aging of BrC aerosols represents an important source of secondary BrC and can have a pronounced effect on atmospheric chemistry and air pollution. AU - Li, C.* AU - He, Q.* AU - Hettiyadura, A.P.S.* AU - Käfer, U. AU - Shmul, G.* AU - Meidan, D.* AU - Zimmermann, R. AU - Brown, S.S.* AU - George, C.* AU - Laskin, A.* AU - Rudich, Y.* C1 - 57505 C2 - 47816 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 1395-1405 TI - Formation of Secondary Brown Carbon in Biomass Burning Aerosol Proxies through NO3 Radical Reactions. JO - Environ. Sci. Technol. VL - 54 IS - 3 PB - Amer Chemical Soc PY - 2020 SN - 0013-936X ER - TY - JOUR AB - Epidemiological studies have indicated the thyroid-disrupting effects of persistent organic pollutants (POPs). However, the association of low-exposure POPs with thyroid hormones (THs) remains unclear. Here, we aim to assess the association of low exposure of POPs, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and polybrominated dibenzo-p-dioxins and furans, with THs [total (L)-thyroxine (TT4), total 3,3',5-triiodo-L-thyronine (TT3), and total 3,3',5'-triiodo-(L)-thyronine (TrT3)] measured in human breast milk. Ninety-nine breast milk samples were collected from the LUPE cohort (2015-2016, Bavaria, Germany). Fourteen PBDEs, 17 PCBs, and 5 PCDD/Fs had quantification rates of >80%. Nonmonotonic associations were observed. In adjusted single-pollutant models, (1) TT4 was inversely associated with BDE-99,-154, and-196; (2) TT3 was inversely associated with BDE-47,-99,-100,-197,-203,-207, and OCDD; and (3) TrT3 was inversely associated with BDE-47, -99,-183, and -203. Multipollutant analysis using principal component analysis and hierarchical clustering revealed inverse associations of PBDEs (BDE-28,-47,-99,-100,-154,-183, and-197) with TT4 and TrT3. These results indicate that POPs at low levels might be related to reduced THs. This study shows that human breast milk might be an appropriate specimen to evaluate the thyroid disruption of POPs. AU - Li, Z.M. AU - Albrecht, M.* AU - Fromme, H.* AU - Schramm, K.-W. AU - de Angelis, M. C1 - 57801 C2 - 47966 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 1111-1119 TI - Persistent organic pollutants in human breast milk and associations with maternal thyroid hormone homeostasis. JO - Environ. Sci. Technol. VL - 54 IS - 2 PB - Amer Chemical Soc PY - 2020 SN - 0013-936X ER - TY - JOUR AB - Desphenylchloridazon (DPC), the main metabolite of the herbicide chloridazon (CLZ), is more water soluble and persistent than CLZ and frequently detected in water bodies. When assessing DPC transformation in the environment, results can be nonconclusive if based on concentration analysis alone because estimates may be confounded by simultaneous DPC formation from CLZ. This study investigated the fate of DPC by combining concentration-based methods with compound-specific C and N stable isotope analysis (CSIA). Additionally, DPC formation and transformation processes were experimentally deconvolved in a dedicated lysimeter study considering three scenarios. First, surface application of DPC enabled studying its degradation in the absence of CLZ. Here, CSIA provided evidence of two distinct DPC transformation processes: one shows significant changes only in C-13/C-12, whereas the other involves changes in both C-13/C-12 and N-15/N-14 isotope ratios. Second, surface application of CLZ mimicked a realistic field scenario, showing that during DPC formation, C-13/C-12 ratios of DPC were depleted in C-13 relative to CLZ, while N-15/N-14 ratios remained constant. Finally, CLZ depth injection simulated preferential flow and demonstrated the importance of the topsoil for retaining DPC. The combination of the lysimeter study with CSIA enabled insights into DPC transformation in the field that are superior to those of studies of concentration trends. AU - Melsbach, A. AU - Torrentó, C.* AU - Ponsin, V.* AU - Bolotin, J.* AU - Lachat, L.* AU - Prasuhn, V.* AU - Hofstetter, T.B.* AU - Hunkeler, D.* AU - Elsner, M. C1 - 58849 C2 - 48504 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 3929-3939 TI - Dual-element isotope analysis of desphenylchloridazon to investigate its environmental fate in a systematic field study: A long-term lysimeter experiment. JO - Environ. Sci. Technol. VL - 54 IS - 7 PB - Amer Chemical Soc PY - 2020 SN - 0013-936X ER - TY - JOUR AB - Natural organic matter and humic substances (HS) in soils and sediments participate in numerous biogeochemical processes. Sorption to redox-inert aluminum oxide (Al2O3) was recently found to affect the redox properties of HS both in sorbed and dissolved state. With this study, we aim to decipher the molecular basis for these observations by applying Fourier transform ion cyclotron resonance mass spectrometry (FT-ICRMS) and mediated electrochemical analysis to Elliott soil, Pahokee peat, and Suwannee river humic acid (HA) samples before and after sorption to polar Al2O3 and a nonpolar sorbent (DAX-8 resin). The FT-ICRMS data provided evidence of preferential sorption of specific HA fractions, primarily tannin-like compounds, to Al2O3. These oxygen-rich compounds bear a high density of redox-active functional groups, and their adsorption leads to a depletion of electron exchange capacity in dissolved HAs and enrichment of HAs adsorbed at Al2O3. Sorption of HAs to DAX-8 was less selective and caused only slight changes in electron exchange capacities of dissolved and sorbed HA fractions. By combining FT-ICRMS and electrochemical approaches, our findings suggest that a selective sorption of oxygen-rich compounds in HA fractions to mineral oxides is a decisive factor for the different redox properties of dissolved and sorbed HA fractions. AU - Subdiaga, E.* AU - Harir, M. AU - Orsetti, S.* AU - Hertkorn, N. AU - Schmitt-Kopplin, P. AU - Haderlein, S.B.* C1 - 57898 C2 - 48169 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 1837-1847 TI - Preferential sorption of tannins at aluminum oxide affects the electron exchange capacities of dissolved and sorbed humic acid fractions. JO - Environ. Sci. Technol. VL - 54 IS - 3 PB - Amer Chemical Soc PY - 2020 SN - 0013-936X ER - TY - JOUR AB - The UV/H2O2 process is a promising advanced oxidation process (AOP) for micropollutant abatement in drinking water treatment and water reuse plants. However, during micropollutant degradation by the AOP, dissolved organic matter (DOM) and the disinfection byproduct (DBP) formation potential may also be altered. This study investigated the influence of the UV/H2O2 AOP on the elemental composition and DBP formation potential of two DOM isolates by using ultrahigh-resolution mass spectrometry (UHRMS). After the AOP, 629 new chemical formulas with an increased degree of oxidation and decreased aromaticity were obtained. Such alterations led to the formation of 226 unknown DBPs with decreased aromaticity indices (AImod) in the subsequent 3-day chlorination. Links between the unknown DBPs and the corresponding precursors in DOM were visualized by network computational analysis. The analysis gave three zones in the van Krevelen diagram based on the possibility of the C7-22HnOm formulas located in each zone to link to the corresponding DBPs. A further investigation with two model compounds reconfirmed the hydroxylation and ring cleavage of DOM by HO· attack during the AOP and the influence on DBP formation. These results obtained from UHRMS build the connection between the elemental composition of DOM and the formation potential of DBPs. AU - Xiang, Y.* AU - Gonsior, M.* AU - Schmitt-Kopplin, P. AU - Shang, C.* C1 - 60620 C2 - 49423 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 14964-14973 TI - Influence of the UV/H2O2 advanced oxidation process on dissolved organic matter and the connection between elemental composition and disinfection byproduct Ffrmation. JO - Environ. Sci. Technol. VL - 54 IS - 23 PB - Amer Chemical Soc PY - 2020 SN - 0013-936X ER - TY - JOUR AB - Biodegradation of persistent micropollutants like pesticides often slows down at low concentrations (mu g/L) in the environment. Mass transfer limitations or physiological adaptation are debated to be responsible. Although promising, evidence from compound-specific isotope fractionation analysis (CSIA) remains unexplored for bacteria adapted to this low concentration regime. We accomplished CSIA for degradation of a persistent pesticide, atrazine, during cultivation of Arthrobacter aurescens TCl in chemostat under four different dilution rates leading to 82, 62, 45, and 32 mu g/L residual atrazine concentrations. Isotope analysis of atrazine in chemostat experiments with whole cells revealed a drastic decrease in isotope fractionation with declining residual substrate concentration from epsilon(C) = -5.36 +/- 0.20 parts per thousand at 82 mu g/L to epsilon(C) = -2.32 +/- 0.28 parts per thousand at 32 mu g/L. At 82 mu g/L epsilon(C) represented the full isotope effect of the enzyme reaction. At lower residual concentrations smaller epsilon(C) indicated that this isotope effect was masked indicating that mass transfer across the cell membrane became rate-limiting. This onset of mass transfer limitation appeared in a narrow concentration range corresponding to about 0.7 mu M assimilable carbon. Concomitant changes in cell morphology highlight the opportunity to study the role of this onset of mass transfer limitation on the physiological level in cells adapted to low concentrations. AU - Ehrl, B. AU - Kundu, K. AU - Gharasoo, M. AU - Marozava, S. AU - Elsner, M. C1 - 55092 C2 - 46072 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 1197-1205 TI - Rate-limiting mass transfer in micropollutant degradation revealed by isotope fractionation in chemostat. JO - Environ. Sci. Technol. VL - 53 IS - 3 PB - Amer Chemical Soc PY - 2019 SN - 0013-936X ER - TY - JOUR AB - We present a framework to model microbial transformations in chemostats and retentostats under transient or quasi-steady state conditions. The model accounts for transformation-induced isotope fractionation and mass transfer across the cell membrane. It also verifies that the isotope fractionation epsilon can be evaluated as the difference of substrate-specific isotope ratios between inflow and outflow. We explicitly considered that the dropwise feeding of substrate into the reactor at very low dilution rates leads to transient behavior of concentrations and transformation rates and use this information to validate conditions under which a quasi-steady state treatment is justified. We demonstrate the practicality of the code by modeling a chemostat experiment of atrazine degradation at low dilution/growth rates by the strain Arthrobacter aurescens TCl. Our results shed light on the interplay of processes that control biodegradation and isotope fractionation of contaminants at low (mu g/L) concentration levels. With the help of the model, an estimate of the mass-transfer coefficient of atrazine through the cell membrane was achieved (0.0025s(-1)). AU - Gharasoo, M. AU - Ehrl, B. AU - Cirpka, O.A.* AU - Elsner, M. C1 - 55548 C2 - 46201 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 1186-1196 TI - Modeling of contaminant biodegradation and compound-specific isotope fractionation in chemostats at low dilution rates. JO - Environ. Sci. Technol. VL - 53 IS - 3 PB - Amer Chemical Soc PY - 2019 SN - 0013-936X ER - TY - JOUR AB - Trichloromethane (TCM) is a frequently detected and persistent groundwater contaminant. Recent studies have reported that two closely related Dehalobacter strains (UNSWDHB and CF) transform TCM to dichloromethane, with inconsistent carbon isotope effects (e(13)C(UNSWDHB) = -4.3 +/- 0.45 parts per thousand; e13C(CF) = -27.5 +/- 0.9 parts per thousand). This study uses dual element compound specific isotope analysis (C; Cl) to explore the underlying differences. TCM transformation experiments using strain CF revealed pronounced normal carbon and chlorine isotope effects (e13C(CF) = -27.9 +/- 1.7 parts per thousand; e37Cl(CF) = -4.2 +/- 0.2 parts per thousand). In contrast, small carbon and unprecedented inverse chlorine isotope effects were observed for strain UNSWDHB (e13C(UNSWDHB) = -3.1 +/- 0.5 parts per thousand; e37Cl(UNSWDHB) = 2.5 +/- 0.3 parts per thousand) leading to opposing dual element isotope slopes (?CF = 6.64 +/- 0.14 vs lambda(UNSWDHB) = -1.20 +/- 0.18). Isotope effects of strain CF were identical to experiments with TCM and Vitamin B12 (e13C(Vitamin B12) = -26.0 +/- 0.9 parts per thousand, e37Cl(Vitamin B12) = -4.0 +/- 0.2 parts per thousand, lambda(Vitamin) (B12) = 6.46 +/- 0.20). Comparison to previously reported isotope effects suggests outer-sphere-single-electron transfer or S(N)2 as possible underlying mechanisms. Cell suspension and cell free extract experiments with strain UNSWDHB were both unable to unmask the intrinsic KIE of the reductive dehalogenase (TmrA) suggesting that enzyme binding and/or mass-transfer into the periplasm were rate-limiting. Nondirected intermolecular interactions of TCM with cellular material were ruled out as reason for the inverse isotope effect by gas/water and gas/hexadecane partitioning experiments indicating specific, yet uncharacterized interactions must be operating prior to catalysis. AU - Heckel, B. AU - Phillips, E.* AU - Edwards, E.* AU - Sherwood Lollar, B.* AU - Elsner, M. AU - Manefield, M.J.* AU - Lee, M.* C1 - 55635 C2 - 46442 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 2332-2343 TI - Reductive dehalogenation of trichloromethane by two different dehalobacter restrictus strains reveal opposing dual element isotope effects. JO - Environ. Sci. Technol. VL - 53 IS - 5 PB - Amer Chemical Soc PY - 2019 SN - 0013-936X ER - TY - JOUR AB - Growing literature has documented varying toxic potencies of source- or site-specific fine particulate matter (PM2.5), as opposed to the practice that treats particle toxicities as independent of composition given the incomplete understanding of the toxicity of the constituents. Quantifying component-specific contribution is the key to unlocking the geographical disparities of particle toxicity from a mixture perspective. In this study, we performed integrated mixture toxicity experiments and modeling to quantify the contribution of metals and polycyclic aromatic hydrocarbons (PAHs), two default culprit component groups of PM2.5 toxicity, to in vitro oxidative stress caused by wintertime PM2.5 from Beijing and Guangzhou, two megacities in China. PM2.5 from Beijing exhibited greater toxic potencies at equal mass concentrations. The targeted chemical analysis revealed higher burden of metals and PAHs per unit mass of PM2.5 in Beijing. These chemicals together explained 38 and 24% on average of PM2.5-induced reactive oxygen species in Beijing and Guangzhou, respectively, while >60% of the effects remained to be resolved in terms of contributing chemicals. PAHs contributed approximately twice the share of the PM2.5 mixture effects as metals. Fe, Cu, and Mn were the dominant metals, constituting >80% of the metal-shared proportion of the PM2.5 effects. Dibenzo[a,l]pyrene alone explained >65% of the PAH-shared proportion of the PM2.5 toxicity effects. The significant contribution from coal combustion and vehicular emissions in Beijing suggested the major source disparities of toxicologically active PAHs between the two cities. Our study provided novel quantitative insights into the role of varying toxic component profiles in shaping the differential toxic potencies of city-specific PM2.5 pollution. AU - Jin, L.* AU - Xie, J.* AU - Wong, C.K.C.* AU - Chan, S.K.Y.* AU - Abbaszade, G. AU - Schnelle-Kreis, J. AU - Zimmermann, R. AU - Li, J.* AU - Zhang, G.* AU - Fu, P.* AU - Li, X.* C1 - 55645 C2 - 46457 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 2881-2891 TI - Contributions of city-specific fine particulate matter (PM2.5) to differential in vitro oxidative stress and toxicity implications between Beijing and Guangzhou of China. JO - Environ. Sci. Technol. VL - 53 IS - 5 PB - Amer Chemical Soc PY - 2019 SN - 0013-936X ER - TY - JOUR AB - Tetrachloroethene (PCE) and trichloroethene (TCE) are significant groundwater contaminants. Microbial reductive dehalogenation at contaminated sites can produce nontoxic ethene but often stops at toxic cis-1,2-dichloroethene (cis-DCE) or vinyl chloride (VC). The magnitude of carbon relative to chlorine isotope effects (as expressed by Lambda(C/Cl), the slope of delta C-13 versus delta Cl-37 regressions) was recently recognized to reveal different reduction mechanisms with vitamin B-12 as a model reactant for reductive dehalogenase activity. Large Lambda(C/Cl) values for cis-DCE reflected cob(I)alamin addition followed by protonation, whereas smaller Lambda(C/Cl) values for PCE evidenced cob(I)alamin addition followed by Cl- elimination. This study addressed dehalogenation in actual microorganisms and observed identical large Lambda(C/Cl) values for cis-DCE (Lambda(C/Cl) = 10.0 to 17.8) that contrasted with identical smaller Lambda(C/Cl) for TCE and PCE (Lambda(C/Cl) = 2.3 to 3.8). For TCE, the trend of small Lambda(C/Cl) could even be reversed when mixed cultures were precultivated on VC or DCEs and subsequently confronted with TCE (Lambda(C/Cl) = 9.0 to 18.2). This observation provides explicit evidence that substrate adaptation must have selected for reductive dehalogenases with different mechanistic motifs. The patterns of Lambda(C/Cl) are consistent with practically all studies published to date, while the difference in reaction mechanisms offers a potential answer to the long-standing question of why bioremediation frequently stalls at cis-DCE. AU - Lihl, C. AU - Douglas, L.M.* AU - Franke, S.* AU - Pérez-de-Mora, A. AU - Meyer, A.H. AU - Daubmeier, M. AU - Edwards, E.A.* AU - Nijenhuis, I.* AU - Sherwood Lollar, B.* AU - Elsner, M. C1 - 55936 C2 - 46673 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 4245-4254 TI - Mechanistic dichotomy in bacterial trichloroethene dechlorination revealed by carbon and chlorine isotope effects. JO - Environ. Sci. Technol. VL - 53 IS - 8 PB - Amer Chemical Soc PY - 2019 SN - 0013-936X ER - TY - JOUR AB - While they are theoretically conceptualized to restrict biodegradation of organic contaminants, bioavailability limitations are challenging to observe directly. Here we explore the onset of mass transfer limitations during slow biodegradation of the polycyclic aromatic hydrocarbon 2-methylnaphthalene (2-MN) by the anaerobic, sulfate-reducing strain NaphS2. Carbon and hydrogen compound specific isotope fractionation was pronounced at high aqueous 2-MN concentrations (60 μM) (ϵcarbon = -2.1 ± 0.1‰/ϵhydrogen = -40 ± 7‰) in the absence of an oil phase but became significantly smaller (ϵcarbon = -0.9 ± 0.3‰/ϵhydrogen = -6 ± 3‰) or nondetectable when low aqueous concentrations (4 μM versus 0.5 μM) were in equilibrium with 80 or 10 mM 2-MN in hexadecane, respectively. This masking of isotope fractionation directly evidenced mass transfer limitations at (sub)micromolar substrate concentrations. Remarkably, oil-water mass transfer coefficients were 60-90 times greater in biotic experiments than in the absence of bacteria (korg-aq2-MN = 0.01 ± 0.003 cm h-1). The ability of isotope fractionation to identify mass transfer limitations may help study how microorganisms adapt and navigate at the brink of bioavailability at low concentrations. For field surveys our results imply that, at trace concentrations, the absence of isotope fractionation does not necessarily indicate the absence of biodegradation. AU - Marozava, S. AU - Meyer, A.H. AU - Pérez-de-Mora, A. AU - Gharasoo, M. AU - Zhou, L. AU - Wang, H. AU - Cirpka, O.A.* AU - Meckenstock, R.U.* AU - Elsner, M. C1 - 56796 C2 - 47392 SP - 9481-9490 TI - Mass transfer limitation during slow anaerobic biodegradation of 2-methylnaphthalene. JO - Environ. Sci. Technol. VL - 53 IS - 16 PY - 2019 SN - 0013-936X ER - TY - JOUR AB - Estuarine water treated with a ballast water management system (BWMS) using a solution of dissolved dichloroisocyanurate dihydrate (DICD) resulted in the formation of newly described brominated disinfection by-products (Br-DBPs). Analysis of dissolved organic matter (DOM) in untreated water with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) identified 3897 m/z ions and their exact molecular formulas. After DICD treatment, a total of 213 halogenated molecular ions with relative abundance of at least 1% were assigned and confirmed using isotope simulation. Halogenated ions were assigned in four DBP elemental groups including CHOBr (180), CHONBr (13), CHOCl (16), and CHOBrCl (4). Forty-nine of the 197 brominated formulas have not been previously reported. We also were able to tentatively assign possible structures to the formula C3Br3N2 due to very limited isomeric possibilities. The tentatively assigned compound found at 6.4% relative abundance was identified as either tribromoimidazole or tribromopyrazole. Our results show the formation of complex halogenated DBPs that are formed in the treatment of water with a novel BWMS that employs granular DICD as a biocide. The toxicological and mutagenic properties as well as the fate of these newly identified brominated DBPs are unknown. AU - Ziegler, G.* AU - Gonsior, M.* AU - Fisher, D.J.* AU - Schmitt-Kopplin, P. AU - Tamburri, M.N.* C1 - 56724 C2 - 47225 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 8006-8016 TI - Formation of brominated organic compounds and molecular transformations in dissolved organic matter (DOM) after ballast water treatment with sodium dichloroisocyanurate dihydrate (DICD). JO - Environ. Sci. Technol. VL - 53 IS - 14 PB - Amer Chemical Soc PY - 2019 SN - 0013-936X ER - TY - JOUR AB - Skin affections after sulfur mustard (SM) exposure include erythema, blister formation and severe inflammation. An antidote or specific therapy does not exist. Anti-inflammatory compounds as well as substances counteracting SM-induced cell death are under investigation. In this study, we investigated the benzylisoquinoline alkaloide berberine (BER), a metabolite in plants like berberis vulgaris, which is used as herbal pharmaceutical in Asian countries, against SM toxicity using a well-established in vitro approach. Keratinocyte (HaCaT) mono-cultures (MoC) or HaCaT/THP-1 co-cultures (CoC) were challenged with 100, 200 or 300 mM SM for 1 h. Post-exposure, both MoC and CoC were treated with 10, 30 or 50 mu M BER for 24 h. At that time, supernatants were collected and analyzed both for interleukine (IL) 6 and 8 levels and for content of adenylate-kinase (AK) as surrogate marker for cell necrosis. Cells were lysed and nucleosome formation as marker for late apoptosis was assessed. In parallel, AK in cells was determined for normalization purposes. BER treatment did not influence necrosis, but significantly decreased apoptosis. Anti-inflammatory effects were moderate, but also significant, primarily in CoC. Overall, BER has protective effects against SM toxicity in vitro. Whether this holds true should be evaluated in future in vivo studies. AU - Corbin, J.C.* AU - Mensah, A.A.* AU - Pieber, S.M.* AU - Orasche, J. AU - Michalke, B. AU - Zanatta, M.* AU - Czech, H.* AU - Massabò, D.* AU - Buatier De Mongeot, F.* AU - Mennucci, C.* AU - El Haddad, I.* AU - Kumar, N.K.* AU - Stengel, B.* AU - Huang, Y.* AU - Zimmermann, R. AU - Prévôt, A.S.H.* AU - Gysel, M.* C1 - 53709 C2 - 44977 CY - Elsevier House, Brookvale Plaza, East Park Shannon, Co, Clare, 00000, Ireland SP - 6714-6722 TI - Trace metals in soot and PM2.5 from heavy-fuel-oil combustion in a marine engine. JO - Environ. Sci. Technol. VL - 52 IS - 11 PB - Elsevier Ireland Ltd PY - 2018 SN - 0013-936X ER - TY - JOUR AB - Biodegradation of persistent pesticides like atrazine often stalls at low concentrations in the environment. While mass transfer does not limit atrazine degradation by the Gram-positive Arthrobacter aurescens TC1 at high concentrations (>1 mg/L), evidence of bioavailability limitations is emerging at trace concentrations (<0.1 mg/L). To assess the bioavailability constraints on biodegradation, the roles of cell wall physiology and transporters remain imperfectly understood. Here, compound-specific isotope analysis (CSIA) demonstrates that cell wall physiology (i.e., the difference between Gram-negative and Gram-positive bacteria) imposes mass transfer limitations in atrazine biodegradation even at high concentrations. Atrazine biodegradation by Gram-negative Polaromonas sp. Nea-C caused significantly less isotope fractionation (ϵ(C) = -3.5 ‰) than expected for hydrolysis by the enzyme TrzN (ϵ(C) = -5.0 ‰) and observed in Gram-positive Arthrobacter aurescens TC1 (ϵ(C) = -5.4 ‰). Isotope fractionation was recovered in cell-free extracts (ϵ(C) = -5.3 ‰) where no cell envelope restricted pollutant uptake. When active transport was inhibited with cyanide, atrazine degradation rates remained constant demonstrating that atrazine mass transfer across the cell envelope does not depend on active transport but is a consequence of passive cell wall permeation. Taken together, our results identify the cell envelope of the Gram-negative bacterium Polaromonas sp. Nea-C as a relevant barrier for atrazine biodegradation. AU - Ehrl, B. AU - Gharasoo, M. AU - Elsner, M. C1 - 53901 C2 - 45138 SP - 4137-4144 TI - Isotope fractionation pinpoints membrane permeability as a barrier to atrazine biodegradation in gram-negative Polaromonas sp. Nea-C. JO - Environ. Sci. Technol. VL - 52 IS - 7 PY - 2018 SN - 0013-936X ER - TY - JOUR AB - Bacterial uptake of charged organic pollutants such as the widely used herbicide glyphosate is typically attributed to active transporters, whereas passive membrane permeation as an uptake pathway is usually neglected. For 1-palmitoyl-2-oleoyl-snglycero-3-phosphocholine (POPC) liposomes, the pH-dependent apparent membrane permeation coefficients (P-app) of glyphosate, determined by nuclear magnetic resonance (NMR) spectroscopy, varied from P-app (pH 7.0) = 3.7 (+/- 0.3) x 10(-7) m.s(-1) to P-app (pH 4.1) = 4.2 (+/- 0.1) x 10(-6) m.s(-1). The magnitude of this surprisingly rapid membrane permeation depended on glyphosate speciation and was, at circumneutral pH, in the range of polar, noncharged molecules. These findings point to passive membrane permeation as a potential uptake pathway during glyphosate biodegradation. To test this hypothesis, a Gram-negative glyphosate degrader, Ochrobactrum sp. FrEM, was isolated from glyphosate-treated soil and glyphosate permeation rates inferred from the liposome model system were compared to bacterial degradation rates. Estimated maximum permeation rates were, indeed, 2 orders of magnitude higher than degradation rates of glyphosate. In addition, biodegradation of millimolar glyphosate concentrations gave rise to pronounced carbon isotope fractionation with an apparent kinetic isotope effect, AKIE(carbon), of 1.014 +/- 0.003. This value lies in the range typical of non-masked enzymatic isotope fractionation demonstrating that glyphosate biodegradation was not subject to mass transfer limitations and glyphosate exchange across the cell membrane was rapid relative to enzymatic turnover. AU - Ehrl, B. AU - Mogusu, E.O. AU - Kim, K.* AU - Hofstetter, H.* AU - Pedersen, J.A.* AU - Elsner, M. C1 - 53978 C2 - 45168 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 7259-7268 TI - High permeation rates in liposome systems explain rapid glyphosate biodegradation associated with strong isotope fractionation. JO - Environ. Sci. Technol. VL - 52 IS - 13 PB - Amer Chemical Soc PY - 2018 SN - 0013-936X ER - TY - JOUR AB - Residential wood combustion (RWC) emits high amounts of volatile organic compounds (VOCs) into ambient air, leading to formation of secondary organic aerosol (SOA), and various health and climate effects. In this study, the emission factors of VOCs from a logwood-fired modern masonry heater were measured using a Proton-Transfer Reactor Time-of-Flight Mass Spectrometer. Next, the VOCs were aged in a 29 m(3) Teflon chamber equipped with UV black lights, where dark and photochemical atmospheric conditions were simulated. The main constituents of the VOC emissions were carbonyls and aromatic compounds, which accounted for 50%-52% and 30%-46% of the detected VOC emission, respectively. Emissions were highly susceptible to different combustion conditions, which caused a 2.4-fold variation in emission factors. The overall VOC concentrations declined considerably during both dark and photochemical aging, with simultaneous increase in particulate organic aerosol mass. Especially furanoic and phenolic compounds decreased, and they are suggested to be the major precursors of RWC-originated SOA in all aging conditions. On the other hand, dark aging produced relatively high amounts of nitrogen-containing organic compounds in both gas and particulate phase, while photochemical aging increased especially the concentrations of certain gaseous carbonyls, particularly acid anhydrides. AU - Hartikainen, A.L.* AU - Yli-Pirilä, P.* AU - Tiitta, P.* AU - Leskinen, A.* AU - Kortelainen, M.* AU - Orasche, J. AU - Schnelle-Kreis, J. AU - Lehtinen, K.E.J.* AU - Zimmermann, R. AU - Jokiniemi, J.* AU - Sippula, O.* C1 - 53469 C2 - 44745 CY - Washington SP - 4979-4988 TI - Volatile organic compounds from logwood combustion: Emissions and transformation under dark and photochemical aging conditions in a smog chamber. JO - Environ. Sci. Technol. VL - 52 IS - 8 PB - Amer Chemical Soc PY - 2018 SN - 0013-936X ER - TY - JOUR AB - It is widely assumed that biodegradation of trace organic chemicals (TOrCs) in managed aquifer recharge (MAR) systems occurs via a cometabolic transformation with dissolved organic carbon serving as primary substrate. Hence, the composition facilitating bioavailability of the organic matter seems to have a great impact on TOrCs transformation in MAR systems. The aim of this study was to elucidate the character of effluent organic matter present in the feedwater of a simulated sequential MAR system throughout the infiltration by use of FT-ICR-MS analyses as well as spectroscopic methods. Furthermore, compositional changes were correlated with TOrCs targeted throughout the system as well as the abundance of different microbial phyla. On the basis of their behavior throughout the infiltration system in which different redox and substrate conditions prevailed, TOrCs were classified in four groups: easily degradable, redox insensitive, redox sensitive, and persistent. Masses correlating with persistent TOrCs were mainly comprised of CHNO-containing molecules but also of CHO which are known as carboxyl-rich alicyclic molecules, while CHOS and CHNOS can be neglected. Easily degradable TOrCs could be associated with CHNO-, CHO-, and CHOS-containing compounds. However, a shift of molecular compounds to mostly CHOS was observed for redox-insensitive TOrCs. Three hundred thirty eight masses correlated with removal of redox-sensitive TOrCs, but no distinct clustering was identified. AU - Hellauer, K.* AU - Uhl, J. AU - Lucio, M. AU - Schmitt-Kopplin, P. AU - Wibberg, D.* AU - Hübner, U.* AU - Drewes, J.E.* C1 - 54942 C2 - 45948 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 14342-14351 TI - Microbiome triggered transformations of trace organic chemicals in the presence of effluent organic matter in managed aquifer recharge (MAR) systems. JO - Environ. Sci. Technol. VL - 52 IS - 24 PB - Amer Chemical Soc PY - 2018 SN - 0013-936X ER - TY - JOUR AB - Traces of particulate radioactive iodine (I-131) were detected in the European atmosphere in January/February 2017. Concentrations of this nuclear fission product were very low, ranging 0.1 to 10 mu Bq m(-3) except at one location in western Russia where they reached up to several mBq m(-3). Detections have been reported continuously over an 8-week period by about 30 monitoring stations. We examine possible emission source apportionments and rank them considering their expected contribution in terms of orders of magnitude from typical routine releases: radiopharmaceutical production units > sewage sludge incinerators > nuclear power plants > spontaneous fission of uranium in soil. Inverse modeling simulations indicate that the widespread detections of I-131 resulted from the combination of multiple source releases. Among them, those from radiopharmaceutical production units remain the most likely. One of them is located in Western Russia and its estimated source term complies with authorized limits. Other existing sources related to I-131 use (medical purposes or sewage sludge incineration) can explain detections on a rather local scale. As an enhancing factor, the prevailing wintertime meteorological situations marked by strong temperature inversions led to poor dispersion conditions that resulted in higher concentrations exceeding usual detection limits in use within the informal Ring of Five (Ro5) monitoring network. AU - Masson, O.* AU - Steinhauser, G.* AU - Wershofen, H.* AU - Mietelski, J.W.* AU - Fischer, H.W.* AU - Pourcelot, L.* AU - Saunier, O.* AU - Bieringer, J.* AU - Steinkopff, T.* AU - Hýža, M.* AU - Møller, B.* AU - Bowyer, T.W.* AU - Dalaka, E.* AU - Dalheimer, A.* AU - de Vismes-Ott, A.* AU - Eleftheriadis, K.* AU - Forte, M.* AU - Gasco Leonarte, C.* AU - Gorzkiewicz, K.* AU - Homoki, Z.* AU - Isajenko, K.* AU - Karhunen, T.* AU - Katzlberger, C.* AU - Kierepko, R.* AU - Kövendiné Kónyi, J.* AU - Malá, H.* AU - Nikolic, J.* AU - Povinec, P.P.* AU - Rajacic, M.* AU - Ringer, W.* AU - Rulík, P.* AU - Rusconi, R.* AU - Sáfrány, G.* AU - Sýkora, I.* AU - Todorović, D.* AU - Tschiersch, J. AU - Ungar, K.* AU - Zorko, B.* C1 - 54048 C2 - 45240 CY - 1155 16th St, Nw, Washington, Dc 20036 Usa SP - 8488-8500 TI - Potential source apportionment and meteorological conditions involved in airborne 131 I detections in January/February 2017 in Europe. JO - Environ. Sci. Technol. VL - 52 IS - 15 PB - Amer Chemical Soc PY - 2018 SN - 0013-936X ER - TY - JOUR AB - Application of compound-specific stable isotope approaches often involves comparisons of isotope enrichment factors (epsilon). Experimental determination of epsilon-values is based on the Rayleigh equation, which relates the change in measured isotope ratios to the decreasing substrate fractions and is valid for closed systems. Even in well-controlled batch experiments, however, this requirement is not necessarily fulfilled, since repetitive sampling can remove a significant fraction of the analyte. For volatile compounds the need for appropriate corrections is most evident, and various methods have been proposed to account for mass removal and for volatilisation into the headspace. In this study we use both synthetic and experimental data to demonstrate that the determination of epsilon-values according to current correction methods is prone to considerable systematic errors even in well-designed experimental setups. Application of inappropriate methods may lead to incorrect and inconsistent epsilon-values entailing misinterpretations regarding the processes underlying isotope fractionation. In fact, our results suggest that artifacts arising from inappropriate data evaluation might contribute to the variability of published epsilon-values. In response, we present novel, adequate methods to eliminate systematic errors in data evaluation. A model-based sensitivity analysis serves to reveal the most crucial experimental parameters and can be used for future experimental design to obtain correct epsilon-values allowing mechanistic interpretations. AU - Buchner, D.* AU - Jin, B.* AU - Ebert, K.* AU - Rolle, M.* AU - Elsner, M. AU - Haderlein, S.B.* C1 - 50768 C2 - 42864 CY - Washington SP - 1527-1536 TI - Experimental determination of isotope enrichment factors - bias from mass removal by repetitive sampling. JO - Environ. Sci. Technol. VL - 51 IS - 3 PB - Amer Chemical Soc PY - 2017 SN - 0013-936X ER - TY - JOUR AB - The quality of dissolved organic carbon (DOC) affects both carbon cycling in surface waters and drinking water production. Not much is known about the influence of environmental conditions on DOC quality. We studied the effect of redox conditions on the chemical composition of DOC in a drinking water reservoir by Fourier transform ion cyclotron resonance mass spectrometry in combination with sediment core incubation experiments under manipulated redox conditions. We observed clear differences in DOC quality among oxic epilimnion, anoxic hypolimnion, and sediment porewater. Sediment porewater showed relatively high intensities of polyphenol-like components with H/C ratios of < 1 and O/C ratios of > 0.6. Consistent with this, anoxic incubation of a sediment core resulted in an accumulation of these components in the overlying water. The observed pattern of DOC quality change can be explained by redox-dependent adsorption/desorption of DOC on iron minerals. Under oxic conditions, the polyphenol-like components bind on freshly formed iron hydroxides, a process that affects both DOC stability in surface waters and treatability during drinking water production. AU - Dadi, T.* AU - Harir, M. AU - Hertkorn, N. AU - Koschorreck, M.* AU - Schmitt-Kopplin, P. AU - Herzsprung, P.* C1 - 52590 C2 - 44099 CY - Washington SP - 13705-13713 TI - Redox conditions affect dissolved organic carbon quality in stratified freshwaters. JO - Environ. Sci. Technol. VL - 51 IS - 23 PB - Amer Chemical Soc PY - 2017 SN - 0013-936X ER - TY - JOUR AB - Assessing the biodegradation of organic compounds is a frequent question in environmental science. Here, we present a sensitive, inexpensive, and simple approach to monitor microbial mineralization using reverse stable isotope labeling analysis (RIL) of dissolved inorganic carbon (DIC). The medium for the biodegradation assay contains regular organic compounds and 13 C-labeled DIC with 13 C atom fractions (x( 13 C) DIC ) higher than natural abundance (typically 2-50%). The produced CO 2 (x( 13 C) ≈ 1.11%) gradually dilutes the initial x( 13 C) DIC allowing to quantify microbial mineralization using mass-balance calculations. For 13 C-enriched CO 2 samples, a newly developed isotope ratio mid-infrared spectrometer was introduced with a precision of x( 13 C) < 0.006%. As an example for extremely difficult and slowly degradable compounds, CO 2 production was close to the theoretical stoichiometry for anaerobic naphthalene degradation by a sulfate-reducing enrichment culture. Furthermore, we could measure the aerobic degradation of dissolved organic carbon (DOC) adsorbed to granular activated carbon in a drinking water production plant, which cannot be labeled with 13 C. Thus, the RIL approach can be applied to sensitively monitor biodegradation of various organic compounds under anoxic or oxic conditions. AU - Dong, X. AU - Jochmann, M.A.* AU - Elsner, M. AU - Meyer, A.H. AU - Bäcker, L.E.* AU - Rahmatullah, M.* AU - Schunk, D.* AU - Lens, G.* AU - Meckenstock, R.U.* C1 - 52225 C2 - 43815 SP - 11876-11883 TI - Monitoring microbial mineralization using reverse stable isotope labeling analysis by mid-infrared laser spectroscopy. JO - Environ. Sci. Technol. VL - 51 IS - 20 PY - 2017 SN - 0013-936X ER - TY - JOUR AB - Hydrochemical solute concentrations in the shallow subsurface can be spatially highly variable within small scales, particularly at interfaces. However, most monitoring systems fail to capture these small scale variations. Within this study, we developed a high resolution multilevel well (HR-MLW) with which we monitored water across the interface of the unsaturated and saturated zone with a vertical resolution of 0.05-0.5 m. We installed three of these 4 m deep HR-MLWs in the riparian zone of a third-order river and analyzed for hydrochemical parameters and stable water isotopes. The results showed three distinct vertical zones (unsaturated zone, upper saturated zone, lower saturated zone) within the alluvial aquifer. A 2 m thick layer influenced by river water (upper saturated zone) was not captured by existing monitoring wells with higher screen length. Hydrochemical data (isotopes, total ions) were consistent in all HR-MLWs and showed similar variation over time emphasizing the reliability of the installed monitoring system. Further, the depths zones were also reflected in the NO3-N concentrations; with high spatial variabilities between the three wells. The zonation was constant over time, with seasonal variability in the upper saturated zone due to the influence of river water. This study highlights the use of high resolution monitoring for identifying the spatial and temporal variability of hydrochemical parameters present in many aquifer systems. Possible applications range from riparian zones, agricultural field sites to contaminated site studies, wherever an improved understanding of biogeochemical turnover processes is necessary. AU - Gassen, N. AU - Griebler, C. AU - Werban, U.* AU - Trauth, N.* AU - Stumpp, C. C1 - 52514 C2 - 43986 CY - Washington SP - 13806-13815 TI - High resolution monitoring above and below the groundwater table uncovers small-scale hydrochemical gradients. JO - Environ. Sci. Technol. VL - 51 IS - 23 PB - Amer Chemical Soc PY - 2017 SN - 0013-936X ER - TY - JOUR AB - This study explores ibuprofen (IBP) uptake and transformation in the wetland plant species Phragmites australis and the underlying mechanisms. We grew P. australis in perlite under greenhouse conditions and treated plants with 60 μg/L of IBP. Roots and rhizomes (RR), stems and leaves (SL), and liquid samples were collected during 21 days of exposure. Results show that P. australis can take up, translocate, and degrade IBP. IBP was completely removed from the liquid medium after 21 days with a half-life of 2.1 days. IBP accumulated in RR and was partly translocated to SL. Meanwhile, four intermediates were detected in the plant tissues: hydroxy-IBP, 1,2-dihydroxy-IBP, carboxy-IBP and glucopyranosyloxy-hydroxy-IBP. Cytochrome P450 monooxygenase was involved in the production of the two hydroxy intermediates. We hypothesize that transformation of IBP was first catalyzed by P450, and then by glycosyltransferase, followed by further storage or metabolism in vacuoles or cell walls. No significant phytotoxicity was observed based on relative growth of plants and stress enzyme activities. In conclusion, we demonstrated for the first time that P. australis degrades IBP from water and is therefore a suitable species for application in constructed wetlands to clean wastewater effluents containing IBP and possibly also other micropollutants. AU - He, Y.* AU - Langenhoff, A.A.M.* AU - Sutton, N.B.* AU - Rijnaarts, H.H.M.* AU - Blokland, M.H.* AU - Chen, F. AU - Huber, C. AU - Schröder, P. C1 - 51301 C2 - 43054 SP - 4576-4584 TI - Metabolism of ibuprofen by Phragmites australis: Uptake and phytodegradation. JO - Environ. Sci. Technol. VL - 51 IS - 8 PY - 2017 SN - 0013-936X ER - TY - JOUR AB - Chlorinated ethenes (CEs) such as perchloroethylene, trichloroethylene and dichloroethylene are notorious groundwater contaminants. Although reductive dehalogenation is key to their environmental and engineered degradation, underlying reaction mechanisms remain elusive. Outer-sphere reductive single electron transfer (OS-SET) has been proposed for such different processes as Vitamin B 12 -dependent biodegradation and zerovalent metal-mediated dehalogenation. Compound-specific isotope effect ( 13 C/ 12 C, 37 Cl/ 35 Cl) analysis offers a new opportunity to test these hypotheses. Defined OS-SET model reactants (CO 2 radical anions, S 2- -doped graphene oxide in water) caused strong carbon (ε C = -7.9‰ to -11.9‰), but negligible chlorine isotope effects (ε Cl = -0.12‰ to 0.04‰) in CEs. Greater chlorine isotope effects were observed in CHCl 3 (ε C = -7.7‰, ε Cl = -2.6‰), and in CEs when the exergonicity of C-Cl bond cleavage was reduced in an organic solvent (reaction with arene radical anions in glyme). Together, this points to dissociative OS-SET (SET to a σ∗ orbital concerted with C-Cl breakage) in alkanes compared to stepwise OS-SET (SET to a π∗ orbital followed by C-Cl cleavage) in ethenes. The nonexistent chlorine isotope effects of chlorinated ethenes in all aqueous OS-SET experiments contrast strongly with pronounced Cl isotope fractionation in all natural and engineered reductive dehalogenations reported to date suggesting that OS-SET is an exception rather than the rule in environmental transformations of chlorinated ethenes. AU - Heckel, B. AU - Cretnik, S. AU - Kliegman, S.* AU - Shouakar-Stash, O.* AU - McNeill, K.* AU - Elsner, M. C1 - 51954 C2 - 43617 CY - Washington SP - 9663-9673 TI - Reductive outer-sphere single electron transfer is an exception rather than the rule in natural and engineered chlorinated ethene dehalogenation. JO - Environ. Sci. Technol. VL - 51 IS - 17 PB - Amer Chemical Soc PY - 2017 SN - 0013-936X ER - TY - JOUR AB - Large volumes of water return to the surface following hydraulic fracturing of deep shale formations to retrieve oil and natural gas. Current understanding of the specific organic constituents in these hydraulic fracturing wastewaters is limited to hydrocarbons and a fraction of known chemical additives. In this study, we analyzed hydraulic fracturing wastewater samples using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) as a nontargeted technique to assign unambiguous molecular formulas to singly charged molecular ions. Halogenated molecular formulas were identified and confirmed using isotopic simulation and MS MS fragmentation spectra., The abundance of halogenated organic compounds in flowback fluids rather than older wastewaters suggested that the observed molecular ions might have been related to hydraulic fracturing additives and related subsurface reactions, such as through the reaction of shale-extracted chloride, bromide, and iodide with strong oxidant additives (e.g., hypochlorite, persulfate, hydrogen peroxide) and subsequently with diverse dissolved organic matter. Some molecular ions matched the exact masses of known disinfection byproducts including diiodoacetic acid, dibromobenzoic acid, and diiodobenzoic acid. The identified halogenated organic compounds, particularly iodinated organic molecules, are absent from inland natural systems and these compounds could therefore play an important role as environmental tracers. AU - Luek, J.L.* AU - Schmitt-Kopplin, P. AU - Mouser, P.J.* AU - Petty, W.T.* AU - Richardson, S.D.* AU - Gonsior, M.* C1 - 51269 C2 - 42954 CY - Washington SP - 5377-5385 TI - Halogenated organic compounds identified in hydraulic fracturing wastewaters using ultrahigh resolution mass spectrometry. JO - Environ. Sci. Technol. VL - 51 IS - 10 PB - Amer Chemical Soc PY - 2017 SN - 0013-936X ER - TY - JOUR AB - This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (εbulk(C) and εbulk(Cl)) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ(13)C/Δδ(37)Cl ≈ εbulk(C)/εbulk(Cl)), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies. AU - Palau, J.* AU - Yu, R.* AU - Hatijah Mortan, S.* AU - Shouakar-Stash, O.* AU - Rosell, M.* AU - Freedman, D.L.* AU - Sbarbati, C.* AU - Fiorenza, S.* AU - Aravena, R.* AU - Marco-Urrea, E.* AU - Elsner, M. AU - Soler, A.* AU - Hunkeler, D.* C1 - 50648 C2 - 42764 SP - 2685-2694 TI - Distinct dual C-Cl isotope fractionation patterns during anaerobic biodegradation of 1,2-dichloroethane: Potential to characterize microbial degradation in the field. JO - Environ. Sci. Technol. VL - 51 IS - 5 PY - 2017 SN - 0013-936X ER - TY - JOUR AB - To use compound-specific isotope analysis for confidently [GRAPHIC] assessing organic contaminant attenuation in the environment, isotope fractionation patterns associated with different transformation mechanisms must first be explored in laboratory experiments. To deliver this information for the common groundwater contaminant chloroform (CF), this study investigated for the first time both carbon and chlorine isotope fractionation for three different engineered reactions: oxidative C-H bond cleavage using heat-activated persulfate, transformation under alkaline conditions (pH similar to 12) and reductive CCl bond cleavage by cast zerovalent iron, Fe(0). Carbon and chlorine isotope fractionation values were -8 +/- 1 parts per thousand and -0.44 +/- 0.06 parts per thousand for oxidation, -57 +/- 5 parts per thousand and -4.4 +/- 0.4 parts per thousand for alkaline hydrolysis (pH 11.84 +/- 0.03), and -33 +/- 11 parts per thousand and -3 +/- 1 parts per thousand for dechlorination, respectively. Carbon and chlorine apparent kinetic isotope effects (AKIEs) were in general agreement with expected mechanisms (CH bond cleavage in oxidation by persulfate, CCl bond cleavage in Fe(0)-mediated reductive dechlorination and E1(CB) elimination mechanism during alkaline hydrolysis) where a secondary AKIE(Cl) (1.00045 +/- 0.00004) was observed for oxidation. The different dual carbon-chlorine (Delta delta C-13 vs Delta delta Cl-37) isotope patterns for oxidation by thermally activated persulfate and alkaline hydrolysis (17 +/- 2 and 13.0 +/- 0.8, respectively) vs reductive dechlorination by Fe(0) (8 +/- 2) establish a base to identify and quantify these CF degradation mechanisms in the field. AU - Torrentó, C.* AU - Palau, J.* AU - Rodríguez-Fernández, D.* AU - Heckel, B. AU - Meyer, A.H. AU - Domènech, C.* AU - Rosell, M.* AU - Soler, A.* AU - Elsner, M. AU - Hunkeler, D.* C1 - 51518 C2 - 43167 CY - Washington SP - 6174-6184 TI - Carbon and chlorine isotope fractionation patterns associated with different engineered chloroform transformation reactions. JO - Environ. Sci. Technol. VL - 51 IS - 11 PB - Amer Chemical Soc PY - 2017 SN - 0013-936X ER - TY - JOUR AB - Primary biological organic aerosols (PBOA) represent a major component of the coarse organic matter (OMCOARSE). Although this fraction affects human health and climate, its quantification and chemical characterization currently remain elusive. We present the quantification of the entire PM10 PBOA mass and its main sources by analyzing size-segregated filter samples collected during summer and winter at the rural site of Payerne (Switzerland), representing a continental Europe background environment. The size-segregated water soluble OM was analyzed by a newly developed offline aerosol mass spectrometric technique (AMS). The spectra were then analyzed by 3-dimensional positive matrix factorization (3D-PMF), showing that PBOA represented the main OMCOARSE source during summer and its contribution to PM10 was as high as that of secondary organic aerosol. We found substantial cellulose contributions to OMCOARSE, which in combination with gas chromatography mass spectrometry molecular markers quantification, underlines the predominance of plant debris. Quantitative polymerase chain reaction (qPCR) analysis instead revealed that the sum of bacterial and fungal spores mass represented only a minor OMCOARSE fraction (<0.1%). X-ray photoelectron spectroscopic (XPS) analysis of C and N binding energies throughout the different size fractions revealed an organic N increase in the PMCOARSE compared to PM1 consistent with AMS observations. AU - Bozzetti, C.* AU - Daellenbach, K.R.* AU - Hueglin, C.* AU - Fermo, P.* AU - Sciare, J.* AU - Kasper-Giebl, A.* AU - Mazar, Y.* AU - Abbaszade, G. AU - El Kazzi, M.* AU - González, R.* AU - Shuster-Meiseles, T.* AU - Flasch, M.* AU - Wolf, R.* AU - Krepelova, A.* AU - Canonaco, F.* AU - Schnelle-Kreis, J. AU - Slowik, J.G.* AU - Zimmermann, R. AU - Rudich, Y.* AU - Baltensperger, U.* AU - El Haddad, I.* AU - Prévôt, A.S.* C1 - 48006 C2 - 39838 CY - Washington SP - 3425-3434 TI - Size-resolved identification, characterization and quantification of primary biological organic aerosol at a European rural site. JO - Environ. Sci. Technol. VL - 50 IS - 7 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Thedeterminationauthors regretofthatambienta calculationcelluloseerrorconcentrationsoccurred infromthe filter loadings in our article “Size-resolved Identification, Characterization and Quantification of Primary Biological Organic Aerosol at a European Rural Site”. This resulted in cellulose concentrations that were biased high by a factor 2. The correct summer average cellulose contribution to the coarse organic matter (OMCOARSE) fraction was 24 ± 12%. The summer cellulose contribution to the water insoluble OMCOARSEwas 43%avg(pg. 3430). Cellulose together with WSOM represented 62% of OMCOARSE(pg. 3430). The median WSPBOA:Cellulose ratio was 0.61, first quartile 0.51, third quartile 0.81 (SI, pg. S20, line 297). This error decreases the initial contribution of cellulose, but does not alter the conclusions of the original article. The Graphical TOC entry and Figure 1 were corrected as follows: AU - Bozzetti, C.* AU - Daellenbach, K.R.* AU - Hueglin, C.* AU - Fermo, P.* AU - Sciare, J.* AU - Kasper-Giebl, A.* AU - Mazar, Y.* AU - Abbaszade, G. AU - El Kazzi, M.* AU - González, R.* AU - Shuster-Meiseles, T.* AU - Flasch, M.* AU - Wolf, R.* AU - Krepelova, A.* AU - Canonaco, F.* AU - Schnelle-Kreis, J. AU - Slowik, J.G.* AU - Zimmermann, R. AU - Rudich, Y.* AU - Baltensperger, U.* AU - El Haddad, I.* AU - Prevot, A.S.H.* C1 - 50231 C2 - 42214 CY - Washington SP - 13177-13178 TI - Correction to :Size-resolved identification, characterization and quantification of primary biological organic aerosol at a european rural site(Environ. Sci. Technol. (2016) 50 (3425−3434) DOI : 10.1021/acs.est.5b05960). JO - Environ. Sci. Technol. VL - 50 IS - 23 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - At numerous groundwater sites worldwide, natural dissolved organic matter (DOM) is quantitatively complemented with petroleum hydrocarbons. To date, research has been focused almost exclusively on the contaminants, but detailed insights of the interaction of contaminant biodegradation, dominant redox processes, and interactions with natural DOM are missing. This study linked on-site high resolution spatial sampling of groundwater with high resolution molecular characterization of DOM and its relation to groundwater geochemistry across a petroleum hydrocarbon plume cross-section. Electrospray- and atmospheric pressure photoionization (ESI, APPI) ultrahigh resolution mass spectrometry (FT-ICR-MS) revealed a strong interaction between DOM and reactive sulfur species linked to microbial sulfate reduction, i.e., the key redox process involved in contaminant biodegradation. Excitation emission matrix (EEM) fluorescence spectroscopy in combination with Parallel Factor Analysis (PARAFAC) modeling attributed DOM samples to specific contamination traits. Nuclear magnetic resonance (NMR) spectroscopy evaluated the aromatic compounds and their degradation products in samples influenced by the petroleum contamination and its biodegradation. Our orthogonal high resolution analytical approach enabled a comprehensive molecular level understanding of the DOM with respect to in situ petroleum hydrocarbon biodegradation and microbial sulfate reduction. The role of natural DOM as potential cosubstrate and detoxification reactant may improve future bioremediation strategies. AU - Dvorski, S. AU - Gonsior, M.* AU - Hertkorn, N. AU - Uhl, J. AU - Müller, H. AU - Griebler, C. AU - Schmitt-Kopplin, P. C1 - 48657 C2 - 41244 CY - Washington SP - 5536-5546 TI - Geochemistry of dissolved organic matter in a spatially highly resolved goundwater petroleum hydrocarbon plume cross-section. JO - Environ. Sci. Technol. VL - 50 IS - 11 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Much interest is directed at the chemical structure of hydraulic fracturing (HF) additives in unconventional gas exploitation. To bridge the gap between existing alphabetical disclosures by function / CAS number and emerging scientific contributions on fate and toxicity, we review the structural properties which motivate HF applications, and which determine environmental fate and toxicity. Our quantitative overview relied on voluntary U.S. disclosures evaluated from the FracFocus registry by different sources and on a House of Representatives ("Waxman") list. Out of over 1000 reported substances, classification by chemistry yielded succinct subsets able to illustrate the rationale of their use, and physicochemical properties relevant for environmental fate, toxicity and chemical analysis. While many substances were non-toxic, frequent disclosures also included notorious groundwater contaminants like petroleum hydrocarbons (solvents), precursors of endocrine disruptors like nonylphenols (non-emulsifiers), toxic propargyl alcohol (corrosion inhibitor), tetramethyl ammonium (clay stabilizer), biocides or strong oxidants. Application of highly oxidizing chemicals, together with occasional disclosures of putative delayed acids and complexing agents (i.e., compounds designed to react in the subsurface) suggests that relevant transformation products may be formed. To adequately investigate such reactions, available information is not sufficient, but instead a full disclosure of HF additives is necessary. AU - Elsner, M. AU - Hoelzer, K. C1 - 48005 C2 - 39837 CY - Washington SP - 3290-3314 TI - Quantitative survey and structural classification of hydraulic fracturing chemicals reported in unconventional gas production. JO - Environ. Sci. Technol. VL - 50 IS - 7 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Recently, laser-based water stable isotope spectrometers have become popular as they enable previously impossible approaches of environmental observations. Consequently, they have been subjected to increasingly heterogeneous atmospheric conditions. However, there is still a severe lack of data on the impact of nonstandardized gas matrices on analyzer performances. Against this background, we investigated the influence of changing proportions of N2, O2, and CO2 in the carrier gas on the isotope measurements of a typical laser-based water stable isotope analyzer (Picarro L2120-i). We combined environmentally relevant mixtures of N2, O2, and CO2 with referenced, flash-evaporated water and found that isotope readings of the same water were altered by up to +14.57‰ for δ(18)O and -35.9‰ for δ(2)H. All tested relationships between carrier gas changes and respective isotope readings were strongly linearly correlated (R(2) > 0.99). Furthermore, an analyzer-measured variable allowed for reliable postcorrection of the biased isotope readings, which we additionally tested on field data. Our findings are of importance for environmental data obtained by analyzers based on the same technology. They are relevant for assays where inconsistent gas matrices or a mismatch in this regard between unknown and reference analyses cannot be excluded, which is in particular common when investigating the soil-vegetation-atmosphere continuum. AU - Gralher, B. AU - Herbstritt, B.* AU - Weiler, M.* AU - Wassenaar, L.I.* AU - Stumpp, C. C1 - 48931 C2 - 41511 CY - Washington SP - 7074-7081 TI - Correcting laser-based water stable isotope readings biased by carrier gas changes. JO - Environ. Sci. Technol. VL - 50 IS - 13 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Unconventional natural gas development (UNGD) generates large volumes of wastewater, the detailed composition of which must be known for adequate risk assessment and treatment. In particular, transformation products of geogenic compounds and disclosed additives have not been described. This study investigated six Fayetteville Shale wastewater samples for organic composition using a suite of one- and two-dimensional gas chromatographic techniques to capture a broad distribution of chemical structures. Following the application of strict compound-identification-confidence criteria, we classified compounds according to their putative origin. Samples displayed distinct chemical distributions composed of typical geogenic substances (hydrocarbons and hopane biomarkers), disclosed UNGD additives (e.g., hydrocarbons, phthalates such as diisobutyl phthalate, and radical initiators such as azobis(isobutyronitrile)), and undisclosed compounds (e.g., halogenated hydrocarbons, such as 2-bromohexane or 4-bromoheptane). Undisclosed chloromethyl alkanoates (chloromethyl propanoate, pentanoate, and octanoate) were identified as potential delayed acids (i.e., those that release acidic moieties only after hydrolytic cleavage, the rate of which could be potentially controlled), suggesting they were deliberately introduced to react in the subsurface. In contrast, the identification of halogenated methanes and acetones suggested that those compounds were formed as unintended byproducts. Our study highlights the possibility that UNGD operations generate transformation products and underscores the value of disclosing additives injected into the subsurface. AU - Hoelzer, K. AU - Sumner, A.J.* AU - Karatum, O.* AU - Nelson, R.K.* AU - Drollette, B.D.* AU - O'Connor, M.P.* AU - D'Ambro, E.L.* AU - Getzinger, G.J.* AU - Ferguson, P.L.* AU - Reddy, C.M.* AU - Elsner, M. AU - Plata, D.L.* C1 - 49094 C2 - 41642 CY - Washington SP - 8036-8048 TI - Indications of transformation products from hydraulic fracturing additives in shale-gas wastewater. JO - Environ. Sci. Technol. VL - 50 IS - 15 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Although diclofenac ranks among the most frequently detected pharmaceuticals in the urban water cycle, its environmental transformation reactions remain imperfectly understood. Biodegradation-induced changes in 15N/14N ratios (εN = -7.1‰ ± 0.4‰) have indicated that compound-specific isotope analysis (CSIA) may detect diclofenac degradation. This singular observation warrants exploration for further transformation reactions. The present study surveys carbon and nitrogen isotope fractionation in other environmental and engineered transformation reactions of diclofenac. While carbon isotope fractionation was generally small, observed nitrogen isotope fractionation in degradation by MnO2 (εN = -7.3‰ ± 0.3‰), photolysis (εN = +1.9‰ ± 0.1‰), and ozonation (εN = +1.5‰ ± 0.2‰) revealed distinct trends for different oxidative transformation reactions. The small, secondary isotope effect associated with ozonation suggests an attack of O3 in a molecular position distant from the N atom. Model reactants for outer-sphere single electron transfer generated large inverse nitrogen isotope fractionation (εN = +5.7‰ ± 0.3‰), ruling out this mechanism for biodegradation and transformation by MnO2. In a river model, isotope fractionation-derived degradation estimates agreed well with concentration mass balances, providing a proof-of-principle validation for assessing micropollutant degradation in river sediment. Our study highlights the prospect of combining CSIA with transformation product analysis for a better assessment of transformation reactions within the environmental life of diclofenac. AU - Maier, M. AU - Prasse, C.* AU - Pati, S.G.* AU - Nitsche, S. AU - Li, Z.* AU - Radke, M.* AU - Meyer, A.H. AU - Hofstetter, T.B.* AU - Ternes, T.A.* AU - Elsner, M. C1 - 49729 C2 - 40886 CY - Washington SP - 10933-10942 TI - Exploring trends of C and N isotope fractionation to trace transformation reactions of diclofenac in natural and engineered systems. JO - Environ. Sci. Technol. VL - 50 IS - 20 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Compound-specific isotope analysis (CSIA) receives increasing interest for its ability to detect natural degradation of pesticides and pharmaceuticals. Despite recent laboratory studies, CSIA investigations of such micropollutants in the environment are still rare. To explore the certainty of information obtainable by CSIA in a near-environmental setting, a pulse of the pesticide bentazone, the pesticide metabolite 2,6-dichlorobenzamide (BAM), and the pharmaceuticals diclofenac and ibuprofen was released into a mesoscale aquifer with quasi-two-dimensional flow. Concentration breakthrough curves (BTC) of BAM and ibuprofen demonstrated neither degradation nor sorption. Bentazone was transformed but did not sorb significantly, whereas diclofenac showed both degradation and sorption. Carbon and nitrogen CSIA could be accomplished in similar concentrations as for "traditional" priority pollutants (low μg/L range), however, at the cost of uncertainties (0.4-0.5‰ (carbon), 1‰ (nitrogen)). Nonetheless, invariant carbon and nitrogen isotope values confirmed that BAM was neither degraded nor sorbed, while significant enrichment of (13)C and in particular (15)N corroborated transformation of diclofenac and bentazone. Retardation of diclofenac was reflected in additional (15)N sorption isotope effects, whereas isotope fractionation of transverse dispersion could not be identified. These results provide a benchmark on the performance of CSIA to monitor the reactivity of micropollutants in aquifers and may guide future efforts to accomplish CSIA at even lower concentrations (ng/L range). AU - Schürner, H.K.V. AU - Maier, M. AU - Eckert, D.* AU - Brejcha, R. AU - Neumann, C.-C. AU - Stumpp, C. AU - Cirpka, O.A.* AU - Elsner, M. C1 - 48607 C2 - 41214 CY - Washington SP - 5729-5739 TI - Compound-specific stable isotope fractionation of pesticides and pharmaceuticals in a mesoscale aquifer model. JO - Environ. Sci. Technol. VL - 50 IS - 11 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Residential wood combustion emissions are one of the major global sources of particulate and gaseous organic pollutants. However, the detailed chemical compositions of these emissions are poorly characterized due to their highly complex molecular compositions, non-ideal combustion conditions and sample preparation steps. In this study, the particulate organic emissions from a masonry heater using three types of wood logs, namely, beech, birch and spruce, were chemically characterized using thermal desorption in situ derivatization coupled to a GCxGC-ToF/MS system. Untargeted data analyses were performed using the comprehensive measurements. Univariate and multivariate chemometric tools, such as analysis of variance (ANOVA), principal component analysis (PCA) and ANOVA simultaneous component analysis (ASCA), were used to reduce the data to highly significant and wood type-specific features. This study reveals substances not previously considered in the literature as meaningful markers for differentiation among wood types. AU - Weggler, B.A. AU - Ly-Verdú, S. AU - Jennerwein, M. AU - Sippula, O.* AU - Reda, A. AU - Orasche, J. AU - Gröger, T.M. AU - Jokiniemi, J.* AU - Zimmermann, R. C1 - 49368 C2 - 41794 CY - Washington SP - 10073-10081 TI - Untargeted identification of wood type-specific markers in particulate matter from wood combustion. JO - Environ. Sci. Technol. VL - 50 IS - 18 PB - Amer Chemical Soc PY - 2016 SN - 0013-936X ER - TY - JOUR AB - Air pollution health studies of fine particulate matter (diameter ≤2.5 μm, PM2.5) often use outdoor concentrations as exposure surrogates. Failure to account for variability of indoor infiltration of ambient PM2.5 and time indoors can induce exposure errors. We developed and evaluated an exposure model for individuals (EMI), which predicts five tiers of individual-level exposure metrics for ambient PM2.5 using outdoor concentrations, questionnaires, weather, and time-location information. We linked a mechanistic air exchange rate (AER) model to a mass-balance PM2.5 infiltration model to predict residential AER (Tier 1), infiltration factors (Tier 2), indoor concentrations (Tier 3), personal exposure factors (Tier 4), and personal exposures (Tier 5) for ambient PM2.5. Using cross-validation, individual predictions were compared to 591 daily measurements from 31 homes (Tiers 1-3) and participants (Tiers 4-5) in central North Carolina. Median absolute differences were 39% (0.17 h(-1)) for Tier 1, 18% (0.10) for Tier 2, 20% (2.0 μg/m(3)) for Tier 3, 18% (0.10) for Tier 4, and 20% (1.8 μg/m(3)) for Tier 5. The capability of EMI could help reduce the uncertainty of ambient PM2.5 exposure metrics used in health studies. AU - Breen, M.S.* AU - Long, T.C.* AU - Schultz, B.D.* AU - Williams, R.W.* AU - Richmond-Bryant, J.* AU - Breen, M.* AU - Langstaff, J.E.* AU - Devlin, R.B.* AU - Schneider, A.E. AU - Burke, J.M.* AU - Batterman, S.A.* AU - Meng, Q.Y.* C1 - 47296 C2 - 40588 SP - 14184-14194 TI - Air pollution Exposure Model for Individuals (EMI) in health studies: Evaluation for ambient PM2.5 in Central North Carolina. JO - Environ. Sci. Technol. VL - 49 IS - 24 PY - 2015 SN - 0013-936X ER - TY - JOUR AU - Elsner, M. AU - Schreglmann, K. AU - Calmano, W.* AU - Bergmann, A.* AU - Vieth-Hillebrand, A.* AU - Wilke, F.D.* AU - Wollin, K.M.* AU - Georgi, A.* AU - Rattei, T.* AU - Hofmann, T.* AU - Micić, V.* AU - Vengosh, A.* AU - Mayer, B.* C1 - 44915 C2 - 37120 CY - Washington SP - 6367-6369 TI - Comment on the German draft legislation on hydraulic fracturing: The need for an accurate state of knowledge and for independent scientific research. JO - Environ. Sci. Technol. VL - 49 IS - 11 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - Volumes of natural gas extraction-derived wastewaters have increased sharply over the past decade, but the ultimate fate of those waste streams is poorly characterized. Here, we sought to (a) quantify natural gas residual fluid sources and endpoints to bound the scope of potential waste stream impacts and (b) describe the organic pollutants discharged to surface waters following treatment, a route of likely ecological exposure. Our findings indicate that centralized waste treatment facilities (CWTF) received 9.5% (8.5 × 10(8) L) of natural gas residual fluids in 2013, with some facilities discharging all effluent to surface waters. In dry months, discharged water volumes were on the order of the receiving body flows for some plants, indicating that surface waters can become waste-dominated in summer. As disclosed organic compounds used in high volume hydraulic fracturing (HVHF) vary greatly in physicochemical properties, we deployed a suite of analytical techniques to characterize CWTF effluents, covering 90.5% of disclosed compounds. Results revealed that, of nearly 1000 disclosed organic compounds used in HVHF, only petroleum distillates and alcohol polyethoxylates were present. Few analytes targeted by regulatory agencies (e.g., benzene or toluene) were observed, highlighting the need for expanded and improved monitoring efforts at CWTFs. AU - Getzinger, G.J.* AU - O'Connor, M.P.* AU - Hoelzer, K. AU - Drollette, B.D.* AU - Karatum, O.* AU - Deshusses, M.A.* AU - Ferguson, P.L.* AU - Elsner, M. AU - Plata, D.L.* C1 - 46288 C2 - 37460 CY - Washington SP - 8347-8355 TI - Natural gas residual fluids: Sources, endpoints, and organic chemical composition after centralized waste treatment in Pennsylvania. JO - Environ. Sci. Technol. VL - 49 IS - 14 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - Microbial degradation is an important process in many environments controlling for instance the cycling of nutrients or the biodegradation of contaminants. At high substrate concentrations toxic effects may inhibit the degradation process. Bioavailability limitations of a degradable substrate can therefore either improve the overall dynamics of degradation by softening the contaminant toxicity effects to microorganisms, or slow down the biodegradation by reducing the microbial access to the substrate. Many studies on biodegradation kinetics of a self-inhibitive substrate have mainly focused on physiological responses of the bacteria to substrate concentration levels without considering the substrate bioavailability limitations rising from different geophysical and geochemical dynamics at pore-scale. In this regard, the role of bioavailability effects on the kinetics of self-inhibiting substrates is poorly understood. In this study, we theoretically analyze this role and assess the interactions between self-inhibition and mass transfer-limitations using analytical/numerical solutions, and show the findings practical relevance for a simple model scenario. Although individually self-inhibition and mass-transfer limitations negatively impact biodegradation, their combined effect may enhance biodegradation rates above a concentration threshold. To our knowledge, this is the first theoretical study describing the cumulative effects of the two mechanisms together. AU - Gholami Gharasoo, M. AU - Centler, F.* AU - van Cappellen, P.* AU - Wick, L.Y.* AU - Thullner, M.* C1 - 44871 C2 - 37161 CY - Washington SP - 5529-5537 TI - Kinetics of substrate biodegradation under the cumulative effects of bioavailability and self-inhibition. JO - Environ. Sci. Technol. VL - 49 IS - 9 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - An extensively diverse array of brominated disinfection byproducts (DBPs) were generated following electrochemical disinfection of natural coastal/estuarine water, which is one of the main treatment methods currently under consideration for ballast water treatment. Ultra-high-resolution mass spectrometry revealed 462 distinct brominated DBPs at a relative abundance in the mass spectra of more than 1%. A brominated DBP with a relative abundance of almost 22% was identified as 2,2,4-tribromo-5-hydroxy-4-cyclopentene-1,3-dione, which is an analogue to several previously described 2,2,4-trihalo-5-hydroxy-4-cyclopentene-1,3-diones in drinking water. Several other brominated molecular formulas matched those of other known brominated DBPs, such as dibromomethane, which could be generated by decarboxylation of dibromoacetic acid during ionization, dibromophenol, dibromopropanoic acid, dibromobutanoic acid, bromohydroxybenzoic acid, bromophenylacetic acid, bromooxopentenoic acid, and dibromopentenedioic acid. Via comparison to previously described chlorine-containing analogues, bromophenylacetic acid, dibromooxopentenoic acid, and dibromopentenedioic acid were also identified. A novel compound at a 4% relative abundance was identified as tribromoethenesulfonate. This compound has not been previously described as a DBP, and its core structure of tribromoethene has been demonstrated to show toxicological implications. Here we show that electrochemical disinfection, suggested as a candidate for successful ballast water treatment, caused considerable production of some previously characterized DBPs in addition to novel brominated DBPs, although several hundred compounds remain structurally uncharacterized. Our results clearly demonstrate that electrochemical and potentially direct chlorination of ballast water in estuarine and marine systems should be approached with caution and the concentrations, fate, and toxicity of DBP need to be further characterized. AU - Gonsior, M.* AU - Mitchelmore, C.* AU - Heyes, A.* AU - Harir, M. AU - Richardson, S.D.* AU - Petty, W.T.* AU - Wright, D.A.* AU - Schmitt-Kopplin, P. C1 - 46484 C2 - 37587 CY - Washington SP - 9048-9055 TI - Bromination of marine dissolved organic matter following full scale electrochemical ballast water disinfection. JO - Environ. Sci. Technol. VL - 49 IS - 15 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - Colloidal iron oxides (FeOx) are increasingly released to the environment due to their use in environmental remediation and biomedical applications, potentially harming living organisms. Size and composition could affect the bioavailability and toxicity of such colloids. Therefore, we investigated the toxicity of selected FeOx with variable aggregate size and variably composed FeOx-associated organic matter (OM) toward the nematode Caenorhabditis elegans. Ferrihydrite colloids containing citrate were taken up by C. elegans with the food and accumulated inside their body. The toxicity of ferrihydrite, goethite, and akaganeite was dependent on aggregate size and specific surface area, with EC50 values for reproduction ranging from 4 to 29 mg Fe L(-1). Experiments with mutant strains lacking mitochondrial superoxide dismutase (sod-2) showed oxidative stress for two FeOx and Fe(3+)-ions, however, revealed that it was not the predominant mechanism of toxicity. The OM composition determined the toxicity of mixed OM-FeOx phases on C. elegans. FeOx associated with humic acids or citrate were less toxic than OM-free FeOx. In contrast, soil-derived ferrihydrite, containing proteins and polysaccharides from mobile OM, was even more toxic than OM-free Fh of similar aggregate size. Consequently, the careful choice of the type of FeOx and the type of associated OM may help in reducing the ecological risks if actively applied to the subsurface. AU - Höss, S.* AU - Fritzsche, A.* AU - Meyer, C. AU - Bosch, J. AU - Meckenstock, R.U. AU - Totsche, K.U.* C1 - 42970 C2 - 35899 CY - Washington SP - 544-552 TI - Size- and composition-dependent toxicity of synthetic and soil-derived Fe oxide colloids for the nematode Caenorhabditis elegans. JO - Environ. Sci. Technol. VL - 49 IS - 1 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - Biodegradation is one of the most favored and sustainable means of removing organic pollutants from contaminated aquifers but the major steering factors are still surprisingly poorly understood. Growing evidence questions some of the established concepts for control of biodegradation. Here, we critically discuss classical concepts such as the thermodynamic redox zonation, or the use of steady state transport scenarios for assessing biodegradation rates. Furthermore, we discuss if absence of specific degrader populations can explain poor biodegradation. We propose updated perspectives on the controls of biodegradation in contaminant plumes. These include the plume fringe concept, transport limitations, and transient conditions as currently underestimated processes affecting biodegradation. AU - Meckenstock, R.U. AU - Elsner, M. AU - Griebler, C. AU - Lueders, T. AU - Stumpp, C. AU - Dejonghe, W.* AU - Bastiaens, L.L.* AU - Springael, D.* AU - Smolders, E.* AU - Boon, N.* AU - Agathos, S.N.* AU - Sorensen, S.R.* AU - Aamand, J.* AU - Albrechtsen, H.J.* AU - Bjerg, P.L.* AU - Schmidt, S.* AU - Huang, W.E.* AU - van Breukelen, B.M.* C1 - 45080 C2 - 37201 SP - 7073-7081 TI - Biodegradation: Updating the concepts of control for microbial clean-up in contaminated aquifers. JO - Environ. Sci. Technol. VL - 49 IS - 12 PY - 2015 SN - 0013-936X ER - TY - JOUR AB - The microbially mediated reactions, that are responsible for field-scale natural attenuation of organic pollutants, are governed by the concurrent presence of a degrading microbial community, suitable energy and carbon sources, electron acceptors, as well as nutrients. The temporal lack of one of these essential components for microbial activity, arising from transient environmental conditions, might potentially impair in-situ biodegradation. This study presents results of small scale flow-through experiments aimed at ascertaining the effects of substrate-starvation periods on the aerobic degradation of toluene by Pseudomonas putida F1. During the course of the experiments, concentrations of attached and mobile bacteria, as well as toluene and oxygen were monitored. Results from a fitted reactive-transport model, along with the observed profiles, show the ability of attached cells to survive substrate-starvation periods of up to four months and suggest a highly dynamic exchange between attached and mobile cells under growth conditions and negligible cell detachment under substrate-starvation conditions. Upon reinstatement of toluene, it was readily degraded without a significant lag period, even after a starvation period of 130 days. Our experimental and modeling results strongly suggest that aerobic biodegradation of BTEX-hydrocarbons at contaminated field sites is not hampered by intermittent starvation periods of up to four months. AU - Mellage, A.* AU - Eckert, D.* AU - Grösbacher, M. AU - Inan, A.Z.* AU - Cirpka, O.A.* AU - Griebler, C. C1 - 45079 C2 - 37200 CY - Washington SP - 7161-7169 TI - Dynamics of suspended and attached aerobic toluene degraders in small-scale flow-through sediment systems under growth and starvation conditions. JO - Environ. Sci. Technol. VL - 49 IS - 12 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - s-Triazine herbicides (atrazine, ametryn) are groundwater contaminants which may undergo microbial hydrolysis. Previously, inverse nitrogen isotope effects in atrazine degradation by Arthrobacter aurescens TC1 (i) delivered highly characteristic (13C/12C, 15N/14N) fractionation trends for pathway identification and (ii) suggested that the s-triazine ring nitrogen was protonated in the enzyme s-triazine hydrolase (TrzN) where (iii) TrzN crystal structure and mutagenesis indicated H+-transfer from the residue E241. This study tested the general validity of these conclusions for atrazine and ametryn with purified TrzN and a TrzN-E241Q site-directed mutant. TrzN-E241Q lacked activity with ametryn; otherwise, degradation consistently showed normal carbon isotope effects (εcarbon = -5.0‰ ± 0.2‰ (atrazine/TrzN), εcarbon = -4.2‰ ± 0.5‰ (atrazine/TrzN-E241Q), εcarbon = -2.4‰ ± 0.3‰ (ametryn/TrzN)) and inverse nitrogen isotope effects (εnitrogen = 2.5‰ ± 0.1‰ (atrazine/TrzN), εnitrogen = 2.1‰ ± 0.3‰ (atrazine/TrzN-E241Q), εnitrogen = 3.6‰ ± 0.4‰ (ametryn/TrzN)). Surprisingly, TrzN-E241Q therefore still activated substrates through protonation implicating another proton donor besides E241. Sulfur isotope effects were larger in enzymatic (εsulfur = -14.7‰ ± 1.0‰, ametryn/TrzN) than in acidic ametryn hydrolysis (εsulfur = -0.2‰ ± 0.0‰, pH 1.75), indicating rate-determining C-S bond cleavage in TrzN. Our results highlight a robust inverse 15N/14N fractionation pattern for identifying microbial s-triazine hydrolysis in the environment caused by multiple protonation options in TrzN. AU - Schürner, H.K.V. AU - Seffernick, J.L.* AU - Grzybkowska, A.* AU - Dybała-Defratyka, A.* AU - Wackett, L.P.* AU - Elsner, M. C1 - 43959 C2 - 36688 CY - Washington SP - 3490-3498 TI - Characteristic isotope fractionation patterns in s-triazine degradation have their origin in multiple protonation options in the s-triazine hydrolase trzn. JO - Environ. Sci. Technol. VL - 49 IS - 6 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - Elemental carbon (EC) or black carbon (BC) in the atmosphere has a strong influence on both climate and human health. In this study, radiocarbon (14C) based source apportionment is used to distinguish between fossil fuel and biomass burning sources of EC isolated from aerosol filter samples collected in Beijing from June 2010 to May 2011. The 14C results demonstrate that EC is consistently dominated by fossil-fuel combustion throughout the whole year with a mean contribution of 79% ± 6% (ranging from 70% to 91%), though EC has a higher mean and peak concentrations in the cold season. The seasonal molecular pattern of hopanes (i.e. a class of organic markers mainly emitted during the combustion of different fossil fuels) indicates that traffic-related emissions are the most important fossil source in the warm period and coal combustion emissions are significantly increased in the cold season. By combining 14C based source apportionment results and picene (i.e. an organic marker for coal emissions) concentrations, relative contributions from coal and vehicle to EC in the cold period were estimated as 25±4% and 50±7%, respectively, whereas the coal combustion contribution was negligible or very small in the warm period. AU - Zhang, Y.* AU - Schnelle-Kreis, J. AU - Abbaszade, G. AU - Zimmermann, R. AU - Zotter, P.* AU - Shen, R.R.* AU - Schaefer, K.* AU - Shao, L.* AU - Prévôt, A.S.* AU - Szidat, S.* C1 - 45602 C2 - 37390 CY - Washington SP - 8408-8415 TI - Source apportionment of elemental carbon in Beijing, China: Insights from radiocarbon and organic marker measurements. JO - Environ. Sci. Technol. VL - 49 IS - 14 PB - Amer Chemical Soc PY - 2015 SN - 0013-936X ER - TY - JOUR AB - Long-term irrigation with untreated wastewater may increase soil microbial adaptation to pollution load and lead to enhanced natural attenuation. We hypothesized that long-term wastewater irrigation accelerates the dissipation of pharmaceuticals. To test our hypothesis we performed an incubation experiment with soils from the Mezquital Valley, Mexico that were irrigated for 0, 14, or 100 years. The results showed that the dissipation half-lives (DT50) of diclofenac (<0.1-1.4 days), bezafibrate (<0.1-4.8 days), sulfamethoxazole (2-33 days), naproxen (6-19 days), carbamazepine (355-1,624 days), and ciprofloxacin were not affected by wastewater irrigation. Trimethoprim dissipation was even slower in soils irrigated for 100 years (DT50: 45-72 days) than in nonirrigated soils (DT50: 12-16 days), was negatively correlated with soil organic matter content and soil-water distribution coefficients, and was inhibited in sterilized soils. Applying a kinetic fate model indicated that long-term irrigation enhanced sequestration of cationic or uncharged trimethoprim and uncharged carbamazepine, but did not affect sequestration of fast-dissipating zwitterions or negatively charged pharmaceuticals. We conclude that microbial adaptation processes play a minor role for pharmaceutical dissipation in wastewater-irrigated soils, while organic matter accumulation in these soils can retard trimethoprim and carbamazepine dissipation. AU - Dalkmann, P.* AU - Siebe, C.* AU - Amelung, W.* AU - Schloter, M. AU - Siemens, J.* C1 - 31120 C2 - 34129 CY - Washington SP - 4963-4970 TI - Does long-term irrigation with untreated wastewater accelerate the dissipation of pharmaceuticals in soil? JO - Environ. Sci. Technol. VL - 48 IS - 9 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - The changes in dissolved organic matter (DOM) throughout the treatment processes in a drinking water treatment plant in Sweden and the formation of disinfection by-products (DBPs) were evaluated by using ultrahigh resolution mass spectrometry (resolution ~ 500,000 at m/z 400) and nuclear magnetic resonance (NMR). Mass spectrometric results revealed that flocculation induced substantial changes in the DOM and caused quantitative removal of DOM constituents that usually are associated with DBP formation. While half of the chromophoric DOM (CDOM) was removed by flocculation, about 4-5 mg L-1 total organic carbon remained in the finished water. A conservative approach revealed the formation of about 800 mass spectrometry ions with unambiguous molecular formula assignments that contained at least one halogen atom. These molecules likely represented new DBPs, which could not be prevented by the flocculation process. The most abundant m/z peaks, associated with formed DBPs, could be assigned to C5HO3Cl3, C5HO3Cl2Br and C5HO3ClBr2 by using isotope simulation patterns with the likely DBPs were produced and suggested the presence of halogenated polyphenolic and aromatic acid-type structures, which was supported by possible structures that matched the lower molecular mass range (max. 10 carbon atoms) of these DBPs. 1H-NMR before and after disinfection revealed about a 2% change of the overall 1H-NMR signals supporting a significant change of the DOM caused by disinfection. This study underlines that a large and increasing number of people are exposed to a very diverse pool of organohalogens through water - by both drinking and uptake through the skin upon contact. Non-target analytical approaches are indispensable to reveal the magnitude of this exposure and to test alternative ways to reduce it. AU - Gonsior, M.* AU - Schmitt-Kopplin, P. AU - Stavklint, H.* AU - Richardson, S.D.* AU - Hertkorn, N. AU - Bastviken, D.* C1 - 32587 C2 - 35139 SP - 12714-12722 TI - Dissolved organic matter changes along treatments of a drinking water plant in Sweden and the formation of previously unknown DBPs. JO - Environ. Sci. Technol. VL - 48 IS - 21 PY - 2014 SN - 0013-936X ER - TY - JOUR AB - Land use regression (LUR) models have been used to model concentrations of mainly traffic related air pollutants (nitrogen oxides (NOx), particulate matter (PM) mass or absorbance). Few LUR models are published of PM composition, whereas the interest in health effects related to particle composition is increasing. The aim of our study was to evaluate LUR models of polycyclic aromatic hydrocarbons (PAH), hopanes/steranes and elemental and organic carbon (EC/OC) content of PM2.5. In 10 European study areas PAH, hopanes/steranes and EC/OC concentrations were measured at 16-40 sites per study area. LUR models for each study area were developed based on annual average concentrations and predictor variables including traffic, population, industry, natural land obtained from geographic information systems. The highest median model explained variance (R2) was found for EC - 84%. The median R2 was 51% for OC, 67% for benzo[a]pyrene and 38% for sum of hopanes/steranes, with large variability between study areas. Traffic predictors were included in most models. Population and natural land were included frequently as additional predictors. The moderate to high explained variance of LUR models and the overall moderate correlation with PM2.5 model predictions support the application of especially the OC and PAH models in epidemiological studies. AU - Jedynska, A.* AU - Hoek, G.* AU - Wang, M.* AU - Eeftens, M.* AU - Cyrys, J. AU - Keuken, M.* AU - Ampe, C.* AU - Beelen, R.* AU - Cesaroni, G.* AU - Forastiere, F.* AU - Cirach, M.* AU - de Hoogh, K.* AU - de Nazelle, A.* AU - Nystad, W.* AU - Declercq, C.* AU - Eriksen, K.T.* AU - Dimakopoulou, K.* AU - Lanki, T.* AU - Meliefste, K.* AU - Nieuwenhuijsen, M.J.* AU - Yli-Tuomi, T.* AU - Raaschou-Nielsen, O.* AU - Brunekreef, B.* AU - Kooter, I.M.* C1 - 32578 C2 - 35131 SP - 14435-14444 TI - Development of land use regression models for elemental, organic carbon, PAH and hopanes/steranes in 10 ESCAPE/TRANSPHORM European study areas. JO - Environ. Sci. Technol. VL - 48 IS - 24 PY - 2014 SN - 0013-936X ER - TY - JOUR AB - The effective density of fine particles emitted from small-scale wood combustion of various fuels were determined with a system consisting of an aerosol particle mass analyzer and a scanning mobility particle sizer (APM-SMPS). A novel sampling chamber was combined to the system to enable measurements of highly fluctuating combustion processes. In addition, mass-mobility exponents (relates mass and mobility size) were determined from the density data to describe the shape of the particles. Particle size, type of fuel, combustion phase, and combustion conditions were found to have an effect on the effective density and the particle shape. For example, steady combustion phase produced agglomerates with effective density of roughly 1 g cm(-3) for small particles, decreasing to 0.25 g cm(-3) for 400 nm particles. The effective density was higher for particles emitted from glowing embers phase (ca. 1-2 g cm(-3)), and a clear size dependency was not observed as the particles were nearly spherical in shape. This study shows that a single value cannot be used for the effective density of particles emitted from wood combustion. AU - Leskinen, J.* AU - Ihalainen, M.* AU - Torvela, T.* AU - Kortelainen, M.* AU - Lamberg, H.* AU - Tiitta, P.* AU - Jakobi, G. AU - Grigonyte, J.* AU - Joutsensaari, J.* AU - Sippula, O.* AU - Tissari, J.* AU - Virtanen, A.* AU - Zimmermann, R. AU - Jokiniemi, J.* C1 - 34364 C2 - 35235 SP - 13298-13306 TI - Effective density and morphology of particles emitted from small-scale combustion of various wood fuels. JO - Environ. Sci. Technol. VL - 48 IS - 22 PY - 2014 SN - 0013-936X ER - TY - JOUR AB - Although diclofenac is frequently found in aquatic systems, its degradability in the environment remains imperfectly understood. On the one hand, evidence from concentration analysis alone is inconclusive if an unknown hydrology impedes a distinction between degradation and dilution. On the other hand, not all transformation products may be detectable. As a new approach, we therefore developed GC-IRMS (gas chromatography-isotope-ratio mass-spectrometry) analysis for carbon and nitrogen isotope measurements of diclofenac. The method uses a derivatization step that can be conducted either online or offline, for optimized throughput or sensitivity, respectively. In combination with on-column injection, the latter method enables determination of diclofenac isotope ratios down to the sub-μgL(-1) range in environmental samples. Degradation in an aerobic sediment-water system showed strong nitrogen isotope fractionation (εN = -7.1‰), whereas reductive diclofenac dechlorination was associated with significant carbon isotope fractionation (εC = -2.0‰). Hence dual element isotope analysis bears potential not only to detect diclofenac degradation, but even to distinguish both transformation pathways in the environment. In an explorative survey, analysis of commercial diclofenac products showed significant differences in carbon and nitrogen isotope ratios, demonstrating a further potential to track, and potentially even to authenticate, commercial production batches. AU - Maier, M. AU - d,e Corte, S.* AU - Nitsche, S. AU - Spaett, T. AU - Boon, N.* AU - Elsner, M. C1 - 29219 C2 - 33180 CY - Washington SP - 2312-2320 TI - C & N isotope analysis of diclofenac to distinguish oxidative and reductive transformation and to track commercial products. JO - Environ. Sci. Technol. VL - 48 IS - 4 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - This study investigates dual element isotope fractionation during aerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via oxidative cleavage of a C–H bond (Pseudomonas sp. strain DCA1) versus C–Cl bond cleavage by SN2 reaction (Xanthobacter autotrophicus GJ10 and Ancylobacter aquaticus AD20). Compound-specific chlorine isotope analysis of 1,2-DCA was performed for the first time, and isotope fractionation (εbulkCl) was determined by measurements of the same samples in three different laboratories using two gas chromatography–isotope ratio mass spectrometry systems and one gas chromatography–quadrupole mass spectrometry system. Strongly pathway-dependent slopes (Δδ13C/Δδ37Cl), 0.78 ± 0.03 (oxidation) and 7.7 ± 0.2 (SN2), delineate the potential of the dual isotope approach to identify 1,2-DCA degradation pathways in the field. In contrast to different εbulkC values [−3.5 ± 0.1‰ (oxidation) and −31.9 ± 0.7 and −32.0 ± 0.9‰ (SN2)], the obtained εbulkCl values were surprisingly similar for the two pathways: −3.8 ± 0.2‰ (oxidation) and −4.2 ± 0.1 and −4.4 ± 0.2‰ (SN2). Apparent kinetic isotope effects (AKIEs) of 1.0070 ± 0.0002 (13C-AKIE, oxidation), 1.068 ± 0.001 (13C-AKIE, SN2), and 1.0087 ± 0.0002 (37Cl-AKIE, SN2) fell within expected ranges. In contrast, an unexpectedly large secondary 37Cl-AKIE of 1.0038 ± 0.0002 reveals a hitherto unrecognized involvement of C–Cl bonds in microbial C–H bond oxidation. Our two-dimensional isotope fractionation patterns allow for the first time reliable 1,2-DCA degradation pathway identification in the field, which unlocks the full potential of isotope applications for this important groundwater contaminant. AU - Palau, J.* AU - Cretnik, S. AU - Shouakar-Stash, O.* AU - Höche, M. AU - Elsner, M. AU - Hunkeler, D.* C1 - 31832 C2 - 34789 CY - Washington SP - 9430-9437 TI - C and Cl isotope fractionation of 1,2-dichloroethane displays unique δ13C/δ37Cl patterns for pathway identification and reveals surprising C-Cl bond involvement in microbial oxidation. JO - Environ. Sci. Technol. VL - 48 IS - 16 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - The use of enhanced in situ anaerobic bioremediation (EISB) and bioaugmentation in fractured bedrock is limited compared to its use in granular media. We evaluated EISB for the treatment of trichloroethene (TCE)-impacted groundwater in fractured carbonate rock at a site in Southern Ontario, Canada, with cool average groundwater temperature (similar to 13 degrees C). Borehole-connectivity, contaminant concentrations, and groundwater properties were investigated. Changes in dechlorinating and nondechlorinating populations (fermenters, acetogens, methanogens, and sulfate reducers) were assessed via quantitative PCR (qPCR). During biostimulation with ethanol, concentrations of TCE daughter products cis-dichloroethene (cDCE) and vinyl chloride (VC) decreased in association with an enrichment of vcrA (VC reductive dehalogenase)-carrying Dehalococcoides, whereas ethene production was only moderate. Following bioaugmentation with the mixed dechlorinating culture KB-1, greater concentrations of chloride-a product of dechlorination-was observed in most wells; in addition, ethene production increased significantly in monitoring well locations that had strong hydraulic connectivity to the groundwater recirculation system, while Dehalococcoides and vcrA concentrations did not appreciably vary. Interestingly, increases of 3-4 orders of magnitude of an ethanol-fermenting Bacteroidetes population also present in KB-1 were correlated to improved conversion to ethene, an observation which suggests there could be a causal relationship-for example, better syntrophy and/or synergy among bacterial populations. AU - Pérez-de-Mora, A. AU - Zila, A.* AU - McMaster, M.L.* AU - Edwards, E.A.* C1 - 31698 C2 - 34675 CY - Washington SP - 5770-5779 TI - Bioremediation of chlorinated ethenes in fractured bedrock and associated changes in dechlorinating and nondechlorinating microbial populations. JO - Environ. Sci. Technol. VL - 48 IS - 10 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - Phenoxy acid herbicides are important groundwater contaminants. Stable isotope analysis and enantiomer analysis are well-recognized approaches for assessing in situ biodegradation in the field. In an aerobic degradation survey with six phenoxyacetic acid and three phenoxypropionic acid-degrading bacteria we measured (a) enantiomer-specific carbon isotope fractionation of MCPP ((R,S)-2-(4-chloro-2-methylphenoxy)-propionic acid), DCPP ((R,S)-2-(2,4-dichlorophenoxy)-propionic acid), and 4-CPP ((R,S)-2-(4-chlorophenoxy)-propionic acid); (b) compound-specific isotope fractionation of MCPA (4-chloro-2-methylphenoxyacetic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid); and (c) enantiomer fractionation of MCPP, DCPP, and 4-CPP. Insignificant or very slight (ε = -1.3‰ to -2.0‰) carbon isotope fractionation was observed. Equally small values in an RdpA enzyme assay (εea = -1.0 ± 0.1‰) and even smaller fractionation in whole cell experiments of the host organism Sphingobium herbicidovorans MH (εwc = -0.3 ± 0.1‰) suggest that (i) enzyme-associated isotope effects were already small, yet (ii) further masked by active transport through the cell membrane. In contrast, enantiomer fractionation in MCPP, DCPP, and 4-CPP was pronounced, with enantioselectivities (ES) of -0.65 to -0.98 with Sphingomonas sp. PM2, -0.63 to -0.89 with Sphingobium herbicidovorans MH, and 0.74 to 0.97 with Delftia acidovorans MC1. To detect aerobic biodegradation of phenoxypropionic acids in the field, enantiomer fractionation seems, therefore, a stronger indicator than carbon isotope fractionation. AU - Qiu, S. AU - Gözdereliler, E. AU - Weyrauch, P. AU - Lopez, E.C. AU - Kohler, H.P.* AU - Sørensen, S.R.* AU - Meckenstock, R.U. AU - Elsner, M. C1 - 31209 C2 - 34203 CY - Washington SP - 5501-5511 TI - Small 13C/12C fractionation contrasts with large enantiomer fractionation in aerobic biodegradation of phenoxy acids. JO - Environ. Sci. Technol. VL - 48 IS - 10 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - The role of the corrinoid cofactor in reductive dehalogenation catalysis by tetrachloroethene reductive dehalogenase (PceA) of Sulfurospirillum multivorans was investigated using isotope analysis of carbon and chlorine. Crude extracts containing PceA-harboring either a native norpseudo-B12 or the alternative nor-B12 cofactor-were applied for dehalogenation of tetrachloroethene (PCE) or trichloroethene (TCE), and compared to abiotic dehalogenation with the respective purified corrinoids (norpseudovitamin B12 and norvitamin B12), as well as several commercially available cobalamins and cobinamide. Dehalogenation of TCE resulted in a similar extent of C and Cl isotope fractionation, and in similar dual-element isotope slopes (εC/εCl) of 5.0-5.3 for PceA enzyme and 3.7-4.5 for the corrinoids. Both observations support an identical reaction mechanism. For PCE, in contrast, observed C and Cl isotope fractionation was smaller in enzymatic dehalogenation, and dual-element isotope slopes (2.2-2.8) were distinctly different compared to dehalogenation mediated by corrinoids (4.6-7.0). Remarkably, εC/εCl of PCE depended in addition on the corrinoid type: εC/εCl values of 4.6 and 5.0 for vitamin B12 and norvitamin B12 were significantly different compared to values of 6.9 and 7.0 for norpseudovitamin B12 and dicyanocobinamide. Our results therefore suggest mechanistic and/or kinetic differences in catalytic PCE dehalogenation by enzymes and different corrinoids, whereas such differences were not observed for TCE. AU - Renpenning, J.* AU - Keller, S.* AU - Cretnik, S. AU - Shouakar-Stash, O.* AU - Elsner, M. AU - Schubert, T.* AU - Nijenhuis, I.* C1 - 32496 C2 - 35075 CY - Washington SP - 11837-11845 TI - Combined C and Cl isotope effects indicate differences between corrinoids and enzyme (Sulfurospirillum multivorans PceA) in reductive dehalogenation of tetrachloroethene, but not trichloroethene. JO - Environ. Sci. Technol. VL - 48 IS - 20 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - Plutonium (Pu) and non-natural uranium (U) originating from the Fukushima Daiichi Nuclear Power Plant (FDNPP) were identified in the atmosphere at 120 km distance from the FDNPP analyzing the ratio of number of atoms, following written as n(isotope)/n(isotope), of Pu and U. The n((240)Pu)/n((239)Pu), n((241)Pu)/n((239)Pu), n((234)U)/n((238)U), n((235)U)/n((238)U) and n((236)U)/n((238)U) in aerosol samples collected before and after the FDNPP incident were analyzed by accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICPMS). The activity concentrations of (137)Cs and (134)Cs in the same samples were also analyzed by gamma spectrometry before the destructive analysis. Comparing the time series of analytical data on Pu and U obtained in this study with previously reported data on Pu, U, and radioactive Cs, we concluded that Pu and non-natural U from the FDNPP were transported in the atmosphere directly over a 120 km distance by aerosol and wind within a few days after the reactor hydrogen explosions. Effective dose of Pu were calculated using the data of Pu: (130 ± 21) nBq/m(3), obtained in this study. We found that the airborne Pu contributes only negligibly to the total dose at the time of the incident. However the analytical results show that the amount of Pu and non-natural U certainly increased in the environment after the incident. AU - Shinonaga, T. AU - Steier, P.* AU - Lagos, M.* AU - Ohkura, T.* C1 - 30872 C2 - 33985 CY - Washington SP - 3808-3814 TI - Airborne plutonium and non-natural uranium from the Fukushima DNPP found at 120 km distance a few days after reactor hydrogen explosions. JO - Environ. Sci. Technol. VL - 48 IS - 7 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - The chemical composition of particulate matter (PM) emissions from a medium-speed four-stroke marine engine, operated on both heavy fuel oil (HFO) and distillate fuel (DF), was studied under various operating conditions. PM emission factors for organic matter, elemental carbon (soot), inorganic species and a variety of organic compounds were determined. In addition, the molecular composition of aromatic organic matter was analyzed using a novel coupling of a thermal-optical carbon analyzer with a resonance-enhanced multiphoton ionization (REMPI) mass spectrometer. The polycyclic aromatic hydrocarbons (PAHs) were predominantly present in an alkylated form, and the composition of the aromatic organic matter in emissions clearly resembled that of fuel. The emissions of species known to be hazardous to health (PAH, Oxy-PAH, N-PAH, transition metals) were significantly higher from HFO than from DF operation, at all engine loads. In contrast, DF usage generated higher elemental carbon emissions than HFO at typical load points (50% and 75%) for marine operation. Thus, according to this study, the sulfur emission regulations that force the usage of low-sulfur distillate fuels will also substantially decrease the emissions of currently unregulated hazardous species. However, the emissions of soot may even increase if the fuel injection system is optimized for HFO operation. AU - Sippula, O.* AU - Stengel, B.* AU - Sklorz, M. AU - Streibel, T. AU - Rabe, R.* AU - Orasche, J. AU - Lintelmann, J. AU - Michalke, B. AU - Abbaszade, G. AU - Radischat, C.* AU - Gröger, T.M. AU - Schnelle-Kreis, J. AU - Harndorf, H.* AU - Zimmermann, R. C1 - 32501 C2 - 35080 CY - Washington SP - 11721-11729 TI - Particle emissions from a marine engine: Chemical composition and aromatic emission profiles under various operating conditions. JO - Environ. Sci. Technol. VL - 48 IS - 19 PB - Amer Chemical Soc PY - 2014 SN - 0013-936X ER - TY - JOUR AB - The aim of the present study was to improve the estimation of soil-derived uranium absorption in humans. For this purpose, an in vitro solubility assay was combined with a human study by using a specific edible soil low in uranium. The mean bioaccessibility of the soil-derived uranium, determined by the solubility assay in artificial gastrointestinal fluid, was found to be 7.7% with a standard deviation of 0.2%. The corresponding bioavailability of the soil-derived uranium in humans was assumed to be log-normal distributed with a geometric mean of 0.04% and a 95% confidence interval ranging from 0.0049% to 0.34%. Both results were used to calculate a factor, denoted as fA(sol), which describes the relation between the bioaccessibility and the bioavailability of soil-derived uranium. The geometric mean of fA(sol) was determined to be 0.53% with a 95% confidence interval ranging from 0.06% to 4.43%. Based on fA(sol), it is possible to estimate more realistic values on the bioavailability of uranium for highly uranium-contaminated soils in humans by just performing the applied solubility assay. The results of this study can be further used to obtain more reliable results on the internal dose assessment of ingested highly uranium-contaminated soils. AU - Träber, S.C. AU - Höllriegl, V. AU - Li, W.B. AU - Czeslik, U.* AU - Rühm, W. AU - Oeh, U. AU - Michalke, B. C1 - 42974 C2 - 35903 SP - 14721-14727 TI - Estimating the absorption of soil-derived uranium in humans. JO - Environ. Sci. Technol. VL - 48 IS - 24 PY - 2014 SN - 0013-936X ER - TY - JOUR AB - Chloroethenes like trichloroethene (TCE) are prevalent environmental contaminants, which may be degraded through reductive dechlorination. Chemical models such as cobalamine (vitamin B12) and its simplified analogue cobaloxime have served to mimic microbial reductive dechlorination. To test whether in vitro and in vivo mechanisms agree, we combined carbon and chlorine isotope measurements of TCE. Degradation-associated enrichment factors εcarbon and εchlorine (i.e., molecular-average isotope effects) were -12.2‰ ± 0.5‰ and -3.6‰ ± 0.1‰ with Geobacter lovleyi strain SZ; -9.1‰ ± 0.6‰ and -2.7‰ ± 0.6‰ with Desulfitobacterium hafniense Y51; -16.1‰ ± 0.9‰ and -4.0‰ ± 0.2‰ with the enzymatic cofactor cobalamin; -21.3‰ ± 0.5‰ and -3.5‰ ± 0.1‰ with cobaloxime. Dual element isotope slopes m = Δδ(13)C/ Δδ(37)Cl ≈ εcarbon/εchlorine of TCE showed strong agreement between biotransformations (3.4 to 3.8) and cobalamin (3.9), but differed markedly for cobaloxime (6.1). These results (i) suggest a similar biodegradation mechanism despite different microbial strains, (ii) indicate that transformation with isolated cobalamin resembles in vivo transformation and (iii) suggest a different mechanism with cobaloxime. This model reactant should therefore be used with caution. Our results demonstrate the power of two-dimensional isotope analyses to characterize and distinguish between reaction mechanisms in whole cell experiments and in vitro model systems. AU - Cretnik, S. AU - Thoreson, K.A. AU - Bernstein, A. AU - Ebert, K.* AU - Buchner, D.* AU - Laskov, C.* AU - Haderlein, S.* AU - Shouakar-Stash, O.* AU - Kliegman, S.* AU - McNeill, K.* AU - Elsner, M. C1 - 25991 C2 - 32011 SP - 6855-6863 TI - Reductive dechlorination of TCE by chemical model systems in comparison to dehalogenating bacteria: Insights from dual element isotope analysis (13C/12C, 37Cl/35Cl). JO - Environ. Sci. Technol. VL - 47 IS - 13 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Land Use Regression (LUR) models have been used to describe and model spatial variability of annual mean concentrations of traffic related pollutants such as nitrogen dioxide (NO2), nitrogen oxides (NOx) and particulate matter (PM). No models have yet been published of elemental composition. As part of the ESCAPE project, we measured the elemental composition in both the PM10 and PM2.5 fraction sizes at 20 sites in each of 20 study areas across Europe. LUR models for eight a priori selected elements (copper (Cu), iron (Fe), potassium (K), nickel (Ni), sulfur (S), silicon (Si), vanadium (V), and zinc (Zn)) were developed. Good models were developed for Cu, Fe, and Zn in both fractions (PM10 and PM2.5) explaining on average between 67 and 79% of the concentration variance (R-2) with a large variability between areas. Traffic variables were the dominant predictors, reflecting nontailpipe emissions. Models for V and S in the PM10 and PM2.5 fractions and Si, Ni, and K in the PM10 fraction performed moderately with R-2 ranging from 50 to 61%. Si, NI, and K models for PM2.5 performed poorest with R-2 under 50%. The LUR models are used to estimate exposures to elemental composition in the health studies involved in ESCAPE. AU - de Hoogh, K.* AU - Wang, M.* AU - Adam, M.* AU - Badaloni, C.* AU - Beelen, R.* AU - Birk, M. AU - Cesaroni, G.* AU - Cirach, M.* AU - Declercq, C.* AU - Dedele, A.* AU - Dons, E.* AU - de Nazelle, A.* AU - Eeftens, M.* AU - Eriksen, K.* AU - Eriksson, C.* AU - Fischer, P.* AU - Grazuleviciene, R.* AU - Gryparis, A.* AU - Hoffmann, B.* AU - Jerrett, M.* AU - Katsouyanni, K.* AU - Iakovides, M.* AU - Lanki, T.* AU - Lindley, S.* AU - Madsen, C.* AU - Mölter, A.* AU - Mosler, G.* AU - Nádor, G.* AU - Nieuwenhuijsen, M.* AU - Pershagen, G.* AU - Peters, A. AU - Phuleria, H.* AU - Probst-Hensch, N.* AU - Raaschou-Nielsen, O.* AU - Quass, U.* AU - Ranzi, A.* AU - Stephanou, E.* AU - Sugiri, D.* AU - Schwarze, P.* AU - Tsai, M.Y.* AU - Yli-Tuomi, T.* AU - Varró, M.J.* AU - Vienneau, D.* AU - Weinmayr, G.* AU - Brunekreef, B.* AU - Hoek, G.* C1 - 26569 C2 - 32284 SP - 5778-5786 TI - Development of land use regression models for particle composition in twenty study areas in Europe. JO - Environ. Sci. Technol. VL - 47 IS - 11 PB - Amer Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Separating microbial- and physical-induced effects on the isotope signals of contaminants has been identified as a challenge in interpreting compound-specific isotope data. In contrast to simple analytical tools, such as the Rayleigh equation, reactive-transport models can account for complex interactions of different fractionating processes. The question arises how complex such models must be to reproduce the data while the model parameters remain identifiable. In this study, we reanalyze the high-resolution data set of toluene concentration and toluene-specific δ(13)C from the toluene-pulse experiment performed by Qiu et al. (this issue). We apply five reactive-transport models, differing in their degree of complexity. We uniquely quantify degradation and sorption properties of the system for each model, estimate the contributions of biodegradation-induced, sorption-induced, and transverse-dispersion-induced isotope fractionation to the overall isotope signal, and investigate the error introduced in the interpretation of the data when individual processes are neglected. Our results show that highly resolved data of both concentration and isotope ratios are needed for unique process identification facilitating reliable model calibration. Combined analysis of these highly resolved data demands reactive transport models accounting for nonlinear degradation kinetics and isotope fractionation by both reactive and physical processes such as sorption and transverse dispersion. AU - Eckert, D.* AU - Qiu, S. AU - Elsner, M. AU - Cirpka, O.A.* C1 - 25995 C2 - 32013 SP - 6900-6907 TI - Model complexity needed for quantitative analysis of high resolution isotope and concentration data from a toluene-pulse experiment. JO - Environ. Sci. Technol. VL - 47 IS - 13 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Natural organic matter (NOM) serve as precursors for disinfection byproducts (DBPs) in drinking water production making NOM removal essential in predisinfection treatment processes. We identified molecular formulas of chlorinated DBPs after chlorination and chloramination in four Swedish surface water treatment plants (WTPs) using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chlorine-containing formulas were detected before and after disinfection and were therefore classified to identify DBPs. In total, 499 DBPs were detected, of which 230 have not been reported earlier. The byproducts had, as a group, significantly lower ratio of hydrogen to carbon (H/C) and significantly higher average carbon oxidation state (Cos), double bond equivalents per carbon (DBE/C) and ratio of oxygen to carbon (O/C) compared to Cl-containing components present before disinfection and CHO formulas in samples taken both before and after disinfection. Electrophilic substitution, the proposed most significant reaction pathway for chlorination of NOM, results in carbon oxidation and decreased H/C while O/C and DBE/C is left unchanged. Because the identified DBPs had significantly higher DBE/C and O/C than the CHO formulas we concluded that chlorination of NOM during disinfection is selective toward components with relatively high double bond equivalency and number of oxygen atoms per carbon. Furthermore, choice of disinfectant, dose, and predisinfection treatment at the different WTPs resulted in distinct patterns in the occurrence of DBP formulas. AU - Lavonen, E.E.* AU - Gonsior, M.* AU - Tranvik, L.J.* AU - Schmitt-Kopplin, P. AU - Kohler, S.J.* C1 - 24331 C2 - 31523 SP - 2264-2271 TI - Selective chlorination of natural organic matter: Identification of previously unknown disinfection byproducts. JO - Environ. Sci. Technol. VL - 47 IS - 5 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Segregation and radioactive analysis of aerosols according to their aerodynamic size were performed in France, Austria, the Czech Republic, Poland, Germany and Greece, after the arrival of contaminated air masses following the nuclear accident at the Fukushima Dai-ichi nuclear power plant in March 2011. On the whole and regardless of the location, the highest activity levels correspond either to the finest particle fraction or to the just upper size class. Regarding anthropogenic radionuclides, the Activity Median Aerodynamic Diameter (AMAD) were ranging between 0.25 and 0.71 µm for 137Cs; from 0.17 to 0.69 µm for 134Cs and from 0.30 to 0.53 µm for 131I, thus in the "accumulation mode" of the ambient aerosol (0.1 to 1 µm). AMAD noticed for the naturally occurring radionuclides 7Be and 210Pb ranged from 0.20 to 0.53 µm and 0.29 to 0.52 µm, respectively. Regarding spatial variations, AMAD do not show large differences from place to place compared with what was observed concerning bulk airborne levels registered on the European scale. When air masses arrived in Europe AMAD for 131I were about half those for cesium isotopes. Higher AMAD for cesium probably results from higher AMAD observed at the early stage of the accident in Japan. Lower AMAD for 131I can be explained by the adsorption of gaseous iodine on particles of all sizes met during transport especially small particles. Additionally, weathering conditions (rain) encountered during transport and in Europe in March and April contributed to the equilibrium of the gaseous to total 131I ratio. AMAD slightly increased with time for 131I whereas a clear decreasing trend was observed with the AMADs for 137Cs and 134Cs. On average, the associated Geometric Standard Deviation (GSD) appeared to be higher for iodine than for cesium isotopes. These statements also bear out a gaseous 131I transfer on ambient particles of a broad size range during transport. Highest weighted activity levels were found on the 0.49-0.95 µm and on the 0.18-0.36 µm size ranges, in France and in Poland, respectively. The contribution from resuspension of old deposited 137Cs was assessed for the coarse particle fractions only for the first sampling week. AU - Masson, O.* AU - Ringer, W.* AU - Malá, H.* AU - Rulík, P.* AU - Dlugosz-Lisiecka, M.* AU - Eleftheriadis, K.* AU - Meisenberg, O. AU - de Vismes-Ott, A.* AU - Gensdarmes, F.* C1 - 27224 C2 - 32572 CY - Washington SP - 10995-11003 TI - Size distributions of airborne radionuclides from the Fukushima nuclear accident at several places in Europe. JO - Environ. Sci. Technol. VL - 47 IS - 19 PB - American Chem. Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Atrazine (Atz) and its metabolite desethylatrazine (DEA) frequently occur in the environment. Conclusive interpretation of their transformation is often difficult. This study explored evidence from (13)C/(12)C and (15)N/(14)N isotope trends in parent and daughter compounds when Atz was dealkylated by (i) permanganate and (ii) the bacterium Rhodococcus sp. NI86/21. In both transformations, (13)C/(12)C ratios of atrazine increased strongly (εcarbon/permanganate = -4.6 ± 0.6‰ and εcarbon/Rhodoccoccus = -3.8 ± 0.2‰), whereas nitrogen isotope fractionation was small. (13)C/(12)C ratios of DEA showed the following trends. (i) When DEA was formed as the only product (Atz + permanganate), (13)C/(12)C remained constant, close to the initial value of Atz, because the carbon atoms involved in the reaction step are not present in DEA. (ii) When DEA was formed together with desisopropylatrazine (biodegradation of Atz), (13)C/(12)C increased but only within 2‰. (iii) When DEA was further biodegraded, (13)C/(12)C increased by up to 9‰ giving strong testimony of the metabolite's breakdown. Two lines of evidence emerge. (a) Enrichment of (13)C/(12)C in DEA, compared to initial Atz, may contain evidence of further DEA degradation. (b) Dual element ((15)N/(14)N versus (13)C/(12)C) isotope plots for dealkylation of atrazine agree with indirect photodegradation but differ from direct photolysis and biotic hydrolysis. Trends in multielement isotope data of atrazine may, therefore, decipher different degradation pathways. AU - Meyer, A.H. AU - Elsner, M. C1 - 25993 C2 - 32012 SP - 6884-6891 TI - 13C/12C and 15N/14N isotope analysis to characterize degradation of atrazine: Evidence from parent and daughter compound values. JO - Environ. Sci. Technol. VL - 47 IS - 13 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - The injection of a mixed toluene and D2O (conservative tracer) pulse into a pristine mesoscale aquifer enabled a first direct experimental comparison of contaminant-specific isotopic fractionation from sorption versus biodegradation and transverse dispersion on a relevant scale. Water samples were taken from two vertically resolved sampling ports at 4.2 m distance. Analysis of deuterium and toluene concentrations allowed quantifying the extent of sorption (R = 1.25) and biodegradation (37% and 44% of initial toluene at the two sampling ports). Sorption and biodegradation were found to directly affect toluene (13)C/(12)C breakthrough curves. In particular, isotope trends demonstrated that biodegradation underwent Michaelis-Menten kinetics rather than first-order kinetics. Carbon isotope enrichment factors obtained from an optimized reactive transport model (Eckert et al., this issue) including a possible isotope fractionation of transverse dispersion were ε(equ)sorption = -0.31 ‰, ε(kin)transverse-dispersion = -0.82 ‰, and ε(kin)biodegradation = -2.15 ‰. Extrapolation of our results to the scenario of a continuous injection predicted that (i) the bias in isotope fractionation from sorption, but not transverse dispersion, may be avoided when the plume reaches steady-state; and (ii) the relevance from both processes is expected to decrease at longer flow distances when isotope fractionation of degradation increasingly dominates. AU - Qiu, S. AU - Eckert, D.* AU - Cirpka, O.A.* AU - Hünniger, M. AU - Knappett, P.S. AU - Maloszewski, P. AU - Meckenstock, R.U. AU - Griebler, C. AU - Elsner, M. C1 - 25480 C2 - 31856 SP - 6892-6899 TI - Direct experimental evidence of non-first order degradation kinetics and sorption-induced isotopic fractionation in a mesoscale aquifer: 13C/12C analysis of a transient toluene pulse. JO - Environ. Sci. Technol. VL - 47 IS - 13 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Toxic metals polluting aquatic ecosystems are taken up by inhabitants and accumulate in the food web, affecting species at all trophic levels. It is therefore important to have good tools to assess the level of risk represented by toxic metals in the environment. Macrophytes are potential organisms for the identification of metal-responsive biomarkers but are still underrepresented in ecotoxicology. In the present study, we used next-generation sequencing to investigate the transcriptomic response of Elodea nuttallii exposed to enhanced concentrations of Hg and Cd. We de novo assembled more than 60 000 contigs, of which we found 170 to be regulated dose-dependently by Hg and 212 by Cd. Functional analysis showed that these genes were notably related to energy and metal homeostasis. Expression analysis using nCounter of a subset of genes showed that the gene expression pattern was able to assess toxic metal exposure in complex environmental samples and was more sensitive than other end points (e.g., bioaccumulation, photosynthesis, etc.). In conclusion, we demonstrate the feasibility of using gene expression signatures for the assessment of environmental contamination, using an organism without previous genetic information. This is of interest to ecotoxicology in a wider sense given the possibility to develop specific and sensitive bioassays. AU - Regier, N.* AU - Baerlocher, L.* AU - Münsterkötter, M. AU - Farinelli, L.* AU - Cosio, C.* C1 - 27387 C2 - 32644 SP - 8825-8834 TI - Analysis of the Elodea nuttallii transcriptome in response to mercury and cadmiumpollution: Development of sensitive tools for rapid ecotoxicological testing. JO - Environ. Sci. Technol. VL - 47 IS - 15 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - A direct comparison between parallel activated sludge and integrated fixed-film activated sludge (IFAS) processes was performed in this study because both treatments received the same primary effluent, although differences may still remain due to different return flow rates. Modern ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry was applied to characterize the complexity of effluent organic matter (EfOM) and to evaluate both processes in their abilities to change the EfOM molecular composition. At different stages during the two processes a direct comparison of the performance and changes in molecular composition of the IFAS with those of the activated sludge was undertaken. Large differences in the molecular composition between both processes were only apparent in the early stage of the aeration cells and the first cell of the IFAS possibly due to the higher flow rate and a delay in aerobic bacterial degradation. Despite the double flow rate (0.263 m(3) s(-1)) in the IFAS reactors compared to the activated sludge, by the end of the treatment the EfOM composition of both processes were undistinguishable from each other. However, a much more complex EfOM was generated in both processes, suggesting that bacteria are responsible for an increase in molecular diversity in the effluent. AU - Tseng, L.Y.* AU - Gonsior, M.* AU - Schmitt-Kopplin, P. AU - Cooper, W.J.* AU - Pitt, P.* AU - Rosso, D.* C1 - 27580 C2 - 32731 SP - 10277-10284 TI - Molecular characteristics and differences of effluent organic matter from parallel activated sludge and Integrated Fixed-film Activated Sludge (IFAS) processes. JO - Environ. Sci. Technol. VL - 47 IS - 18 PB - ACS Publications PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Land use regression models (LUR) frequently use leave-one-out-cross-validation (LOOCV) to assess model fit, but recent studies suggested that this may overestimate predictive ability in independent data sets. Our aim was to evaluate LUR models for nitrogen dioxide (NO2) and particulate matter (PM) components exploiting the high correlation between concentrations of PM metrics and NO2. LUR models have been developed for NO2, PM2.5 absorbance, and copper (Cu) in PM10 based on 20 sites in each of the 20 study areas of the ESCAPE project. Models were evaluated with LOOCV and "hold-out evaluation (HEV)" using the correlation of predicted NO2 or PM concentrations with measured NO2 concentrations at the 20 additional NO2 sites in each area. For NO2, PM2.5 absorbance and PM10 Cu, the median LOOCV R(2)s were 0.83, 0.81, and 0.76 whereas the median HEV R(2) were 0.52, 0.44, and 0.40. There was a positive association between the LOOCV R(2) and HEV R(2) for PM2.5 absorbance and PM10 Cu. Our results confirm that the predictive ability of LUR models based on relatively small training sets is overestimated by the LOOCV R(2)s. Nevertheless, in most areas LUR models still explained a substantial fraction of the variation of concentrations measured at independent sites. AU - Wang, M.* AU - Beelen, R.* AU - Basagana, X.* AU - Becker, T.* AU - Cesaroni, G.* AU - de Hoogh, K.* AU - Dedele, A.* AU - Declercq, C.* AU - Dimakopoulou, K.* AU - Eeftens, M.* AU - Forastiere, F.* AU - Galassi, C.* AU - Grazuleviciene, R.* AU - Hoffmann, B.* AU - Heinrich, J. AU - Iakovides, M.* AU - Künzli, N.* AU - Korek, M.* AU - Lindley, S.* AU - Mölter, A.* AU - Mosler, G.* AU - Madsen, C.* AU - Nieuwenhuijsen, M.* AU - Phuleria, H.* AU - Pedeli, X.* AU - Raaschou-Nielsen, O.* AU - Ranzi, A.* AU - Stephanou, E.* AU - Sugiri, D.* AU - Stempfelet, M.* AU - Tsai, M.Y.* AU - Lanki, T.* AU - Udvardy, O.* AU - Varró, M.J.* AU - Wolf, K. AU - Weinmayr, G.* AU - Yli-Tuomi, T.* AU - Hoek, G.* AU - Brunekreef, B.* C1 - 25137 C2 - 31827 SP - 4357-4364 TI - Evaluation of land use regression models for NO2 and particulate matter in 20 European study areas: The ESCAPE project. JO - Environ. Sci. Technol. VL - 47 IS - 9 PB - Amer. Chemical Soc. PY - 2013 SN - 0013-936X ER - TY - JOUR AB - Pyrite is a key mineral in the global biogeochemical cycles of sulfur and iron, yet its anaerobic microbial oxidation has eluded geochemists and microbiologists for decades. Recent reports indicated that anaerobic oxidation of pyrite is occurring, but the mechanism remains unclear. Here, we provide evidence for the capability of Thiobacillus denitrificans to anaerobically oxidize a putatively nanosized pyrite particle fraction with nitrate as electron acceptor. Nanosized pyrite was readily oxidized to ferric iron and sulfate with a rate of 10.1 μM h(-1). The mass balance of pyrite oxidation and nitrate reduction revealed a closed recovery of the electrons. This substantiates a further "missing lithotrophy" in the global cycles of sulfur and iron and emphasizes the high reactivity of nanominerals in the environment. AU - Bosch, J. AU - Lee, K.Y.* AU - Jordan, G.* AU - Kim, K.W.* AU - Meckenstock, R.U. C1 - 7201 C2 - 29546 SP - 2095-2101 TI - Anaerobic, nitrate-dependent oxidation of pyrite nanoparticles by Thiobacillus denitrificans. JO - Environ. Sci. Technol. VL - 46 IS - 4 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - Land Use Regression (LUR) models have been used increasingly for modeling small-scale spatial variation in air pollution concentrations and estimating individual exposure for participants of cohort studies. Within the ESCAPE project, concentrations of PM(2.5), PM(2.5) absorbance, PM(10), and PM(coarse) were measured in 20 European study areas at 20 sites per area. GIS-derived predictor variables (e.g., traffic intensity, population, and land-use) were evaluated to model spatial variation of annual average concentrations for each study area. The median model explained variance (R(2)) was 71% for PM(2.5) (range across study areas 35-94%). Model R(2) was higher for PM(2.5) absorbance (median 89%, range 56-97%) and lower for PM(coarse) (median 68%, range 32- 81%). Models included between two and five predictor variables, with various traffic indicators as the most common predictors. Lower R(2) was related to small concentration variability or limited availability of predictor variables, especially traffic intensity. Cross validation R(2) results were on average 8-11% lower than model R(2). Careful selection of monitoring sites, examination of influential observations and skewed variable distributions were essential for developing stable LUR models. The final LUR models are used to estimate air pollution concentrations at the home addresses of participants in the health studies involved in ESCAPE. AU - Eeftens, M.* AU - Beelen, R.* AU - de Hoogh, K.* AU - Bellander, T.* AU - Cesaroni, G.* AU - Cirach, M.* AU - Declercq, C.* AU - Dedele, A.* AU - Dons, E.* AU - de Nazelle, A.* AU - Dimakopoulou, K.* AU - Eriksen, K.* AU - Falq, G.* AU - Fischer, P.* AU - Galassi, C.* AU - Grazuleviciene, R.* AU - Heinrich, J. AU - Hoffmann, B.* AU - Jerrett, M.* AU - Keidel, D.* AU - Korek, M.* AU - Lanki, T.* AU - Lindley, S.* AU - Madsen, C.* AU - Mölter, A.* AU - Nádor, G.* AU - Nieuwenhuijsen, M.* AU - Nonnemacher, M.* AU - Pedeli, X.* AU - Raaschou-Nielsen, O.* AU - Patelarou, E.* AU - Quass, U.* AU - Ranzi, A.* AU - Schindler, C.* AU - Stempfelet, M.* AU - Stephanou, E.* AU - Sugiri, D.* AU - Tsai, M.Y.* AU - Yli-Tuomi, T.* AU - Varró, M.J.* AU - Vienneau, D.* AU - von Klot, S.* AU - Wolf, K.* AU - Brunekreef, B.* AU - Hoek, G.* C1 - 10962 C2 - 30453 SP - 11195-11205 TI - Development of land use regression models for PM2.5, PM2.5 absorbance, PM10 and PMcoarse in 20 European study areas: Results of the ESCAPE project. JO - Environ. Sci. Technol. VL - 46 IS - 20 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - Elevated concentrations of dissolved organic matter (DOM) such as humic substances in raw water pose significant challenges during the processing of the commercial drinking water supplies. This is a relevant issue in Saxony, Central East Germany, and many other regions worldwide, where drinking water is produced from raw waters with noticeable presence of chromophoric DOM (CDOM), which is assumed to originate from forested watersheds in spring regions of the catchment area. For improved comprehension of DOM molecular composition, the seasonal and spatial variations of humic-like fluorescence and elemental formulas in the catchment area of the Muldenberg reservoir were recorded by excitation emission matrix fluorescence (EEMF) and ultrahigh-resolution mass spectrometry (FT-ICR-MS). The Spearman rank correlation was applied to link the EEMF intensities with exact molecular formulas and their corresponding relative mass peak abundances. Thereby, humic-like fluorescence could be allocated to the pool of oxygen-rich and relatively unsaturated components with stoichiometries similar to those of tannic acids, which are suspected to have a comparatively high disinfection byproduct formation potential associated with the chlorination of raw water. Analogous relationships were established for UV absorption at 254 nm (UV254) and dissolved organic carbon (DOG) and compared to the EEMF correlation. AU - Herzsprung, P.* AU - von Tümpling, W.* AU - Hertkorn, N. AU - Harir, M. AU - Büttner, O.* AU - Bravidor, J.* AU - Friese, K.* AU - Schmitt-Kopplin, P. C1 - 8053 C2 - 29945 SP - 5511-5518 TI - Variations of DOM quality in inflows of a drinking water reservoir: Linking of van Krevelen diagrams with EEMF spectra by rank correlation. JO - Environ. Sci. Technol. VL - 46 IS - 10 PB - Amer. Chemical Soc. PY - 2012 SN - 0013-936X ER - TY - JOUR AB - The integration of genome-scale, constraint-based models of microbial cell function into simulations of contaminant transport and fate in complex groundwater systems is a promising approach to help characterize the metabolic activities of microorganisms in natural environments. In constraint-based modeling, the specific uptake flux rates of external metabolites are usually determined by Michaelis-Menten kinetic theory. However, extensive data sets based on experimentally measured values are not always available. In this study, a genome-scale model of Pseudomonas putida was used to study the key issue of uncertainty arising from the parametrization of the influx of two growth-limiting substrates: oxygen and toluene. The results showed that simulated growth rates are highly sensitive to substrate affinity constants and that uncertainties in specific substrate uptake rates have a significant influence on the variability of simulated microbial growth. Michaelis-Menten kinetic theory does not, therefore, seem to be appropriate for descriptions of substrate uptake processes in the genome-scale model of P. putida. Microbial growth rates of P. putida in subsurface environments can only be accurately predicted if the processes of complex substrate transport and microbial uptake regulation are sufficiently understood in natural environments and if data-driven uptake flux constraints can be applied. AU - Klier, C. C1 - 7228 C2 - 29575 SP - 2790-2798 TI - Use of an uncertainty analysis for genome-scale models as a prediction tool for microbial growth processes in subsurface environments. JO - Environ. Sci. Technol. VL - 46 IS - 5 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5 to 1.3 log(10)/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence the how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater. AU - Knappett, P.S. AU - McKay, L.D.* AU - Layton, A.* AU - Williams, D.E.* AU - Alam, M.J.* AU - Huq, M.R.* AU - Mey, J.* AU - Feighery, J.E.* AU - Culligan, P.J.* AU - Mailloux, B.J.* AU - Zhuang, J.* AU - Escamilla, V.* AU - Emch, M.* AU - Perfect, E.* AU - Sayler, G.S.* AU - Ahmed, K.M.* AU - van Geen, A.* C1 - 7141 C2 - 29474 SP - 1361-1370 TI - Implications of fecal bacteria input from latrine-polluted ponds for wells in sandy aquifers. JO - Environ. Sci. Technol. VL - 46 IS - 3 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - Chlorinated ethenes are commonly found in contaminated groundwater. Remediation strategies focus on transformation processes that will ultimately lead to nontoxic products. A major concern with these strategies is the possibility of incomplete dechlorination and accumulation of toxic daughter products (cis-1,2-dichloroethene (cDCE), vinyl chloride (VC)). Ethene mass balance can be used as a direct indicator to assess the effectiveness of dechlorination. However, the microbial processes that affect ethene are not well characterized and poor mass balance may reflect biotransformation of ethene rather than incomplete dechlorination. Microbial degradation of ethene is commonly observed in aerobic systems but fewer cases have been reported in anaerobic systems. Limited information is available on the isotope enrichment factors associated with these processes. Using compound-specific isotope analysis (CSIA) we determined the enrichment factors associated with microbial degradation of ethene in anaerobic microcosms (ε = -6.7‰ ± 0.4‰, and -4.0‰ ± 0.8‰) from cultures collected from the Twin Lakes wetland area at the Savannah River site in Georgia (United States), and in aerobic microcosms (ε = -3.0‰ ± 0.3‰) from Mycobacterium sp. strain JS60. Under anaerobic and aerobic conditions, CSIA can be used to determine whether biotransformation of ethene is occurring in addition to biodegradation of the chlorinated ethenes. Using δ(13)C values determined for ethene and for chlorinated ethenes at a contaminated field site undergoing bioremediation, this study demonstrates how CSIA of ethene can be used to reduce uncertainty and risk at a site by distinguishing between actual mass balance deficits during reductive dechlorination and apparent lack of mass balance that is related to biotransformation of ethene. AU - Mundle, S.O.* AU - Johnson, T.* AU - Lacrampe-Couloume, G.* AU - Pérez-de-Mora, A. AU - Duhamel, M.* AU - Edwards, E.A.* AU - McMaster, M.L.* AU - Cox, E.* AU - Révész, K.* AU - Sherwood Lollar, B.* C1 - 7232 C2 - 29570 SP - 1731-1738 TI - Monitoring biodegradation of ethene and bioremediation of chlorinated ethenes at a contaminated site using compound-specific isotope analysis (CSIA). JO - Environ. Sci. Technol. VL - 46 IS - 3 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - 2,6-Dichlorobenzamide (BAM) is a metabolite of the herbicide 2,6-dichlorobenzonitrile (dichlobenil), and a prominent groundwater contaminant. Observable compound-specific isotope fractionation during BAM formation-through transformation of dichlobenil by Rhodococcus erythropolis DSM 9685-was small. In contrast, isotope fractionation during BAM degradation-with Aminobacter sp. MSH1 and ASI1, the only known bacterial strains capable of mineralizing BAM-was large, with pronounced carbon (ε(C) = -7.5‰ to -7.8‰) and nitrogen (ε(N) = -10.7‰ to -13.5‰) isotopic enrichment factors. BAM isotope values in natural samples are therefore expected to be dominated by the effects of its degradation rather than formation. Dual isotope slopes Δ (=Δδ(15)N/Δδ(13)C ≈ ε(N)/ε(C)) showed only small differences for MSH1 (1.75 ± 0.03) and ASI1 (1.45 ± 0.03) suggesting similar transformation mechanisms of BAM hydrolysis. Observations are in agreement with either a tetrahedral intermediate promoted by OH(-) or H(3)O(+) catalysis, or a concerted reaction mechanism. Therefore, owing to consistent carbon isotopic fractionation, isotope shifts of BAM can be linked to BAM biodegradation, and may even be used to quantify degradation of this persistent metabolite. In contrast, nitrogen isotope values may be rather indicative of different sources. Our results delineate a new approach to assessing the fate of BAM in the environment. AU - Reinnicke, S. AU - Simonsen, A.* AU - Sørensen, S.R.* AU - Aamand, J.* AU - Elsner, M. C1 - 7149 C2 - 29489 SP - 1447-1454 TI - C and N isotope fractionation during biodegradation of the pesticide metabolite 2,6-dichlorobenzamide (BAM): Potential for environmental assessments. JO - Environ. Sci. Technol. VL - 46 IS - 3 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - The use of nanoscale ferrihydrite particles, which are known to effectively enhance microbial degradation of a wide range of contaminants, represents a promising technology for in situ remediation of contaminated aquifers. Thanks to their small size, ferrihydrite nanoparticles can be dispersed in water and directly injected into the subsurface to create reactive zones where contaminant biodegradation is promoted. Field applications would require a detailed knowledge of ferrihydrite transport mechanisms in the subsurface, but such studies are lacking in the literature. The present study is intended to fill this gap, focusing in particular on the influence of flow rate and ionic strength on particle mobility. Column tests were performed under constant or transient ionic strength, including injection of ferrihydrite colloidal dispersions, followed by flushing with particle-free electrolyte solutions. Particle mobility was greatly affected by the salt concentration, and particle retention was almost irreversible under typical salt content in groundwater. Experimental results indicate that, for usual ionic strength in European aquifers (2 to 5 mM), under natural flow condition ferrihydrite nanoparticles are likely to be transported for 5 to 30 m. For higher ionic strength, corresponding to contaminated aquifers, (e.g., 10 mM) the travel distance decreases to few meters. A simple relationship is proposed for the estimation of travel distance with changing flow rate and ionic strength. For future applications to aquifer remediation, ionic strength and injection rate can be used as tuning parameters to control ferrihydrite mobility in the subsurface and therefore the radius of influence during field injections. AU - Tosco, T.* AU - Bosch, J. AU - Meckenstock, R.U. AU - Sethi, R.* C1 - 7297 C2 - 29658 SP - 4008-4015 TI - Transport of ferrihydrite nanoparticles in saturated porous media: Role of ionic strength and flow rate. JO - Environ. Sci. Technol. VL - 46 IS - 7 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - In batch experiments, we studied the isotope fractionation in N and O of dissolved nitrate during dentrification. Denitrifying strains Thauera aromatica and "Aromatoleum aromaticum strain EbN1" were grown under strictly anaerobic conditions with acetate, benzoate, and toluene as carbon sources. (18)O-labeled water and (18)O-labeled nitrite were added to the microcosm experiments to study the effect of putative backward reactions of nitrite to nitrate on the stable isotope fractionation. We found no evidence for a reverse reaction. Significant variations of the stable isotope enrichment factor ε were observed depending on the type of carbon source used. For toluene (ε(15)N, -18.1 ± 0.6‰ to -7.3 ± 1.4‰; ε(18)O, -16.5 ± 0.6‰ to -16.1 ± 1.5‰) and benzoate (ε(15)N, -18.9 ± 1.3‰; ε(18)O, -15.9 ± 1.1‰) less negative isotope enrichment factors were calculated compared to those derived from acetate (ε(15)N, -23.5 ± 1.9‰ to -22.1 ± 0.8‰; ε(18)O, -23.7 ± 1.8‰ to -19.9 ± 0.8‰). The observed isotope effects did not depend on the growth kinetics which were similar for the three types of electron donors. We suggest that different carbon sources change the observed isotope enrichment factors by changing the relative kinetics of nitrate transport across the cell wall compared to the kinetics of the intracellular nitrate reduction step of microbial denitrification. AU - Wunderlich, A. AU - Meckenstock, R.U. AU - Einsiedl, F.* C1 - 7475 C2 - 29735 SP - 4861-4868 TI - Effect of different carbon substrates on nitrate stable isotope fractionation during microbial denitrification. JO - Environ. Sci. Technol. VL - 46 IS - 9 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - Dissolved organic matter (DOM) was characterized in eight full scale continuous stirred tank biogas reactors (CSTBR) using solid-phase extraction and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). An overview of the DOM molecular complexity in the samples from biogas reactors with conventional operational conditions and various substrate profiles is provided by assignments of unambiguous exact molecular formulas for each measured mass peak. Analysis of triplicate samples for each reactor demonstrated the reproducibility of the solid-phase extraction procedure and ESI-FT-ICR-MS which allowed precise evaluation of the DOM molecular differences among the different reactors. Cluster analysis on mass spectrometric data set showed that the biogas reactors treating sewage sludge had distinctly different DOM characteristics compared to the codigesters treating a combination of organic wastes. Furthermore, the samples from thermophilic and mesophilic codigesters had different DOM composition in terms of identified masses and corresponding intensities. Despite the differences, the results demonstrated that compositionally linked organic compounds comprising 28-59% of the total number of assigned formulas for the samples were shared in all the reactors. This suggested that the shared assigned formulas in studied CSTBRs might be related to common biochemical transformation in anaerobic digestion process and therefore, performance of the CSTBRs. AU - Yekta, S.S.* AU - Gonsior, M.* AU - Schmitt-Kopplin, P. AU - Svensson, B.H.* C1 - 23163 C2 - 31005 SP - 12711-12719 TI - Characterization of dissolved organic matter in full scale continuous stirred tank biogas reactors using ultrahigh resolution mass spectrometry: A qualitative overview. JO - Environ. Sci. Technol. VL - 46 IS - 22 PB - American Chemical Society PY - 2012 SN - 0013-936X ER - TY - JOUR AB - Anaerobic polycyclic aromatic hydrocarbon (PAH) degradation is a key process for natural attenuation of oil spills and contaminated aquifers. Assessments by stable isotope fractionation, however, have largely been limited to monoaromatic hydrocarbons. Here, we report on measured hydrogen isotope fractionation during strictly anaerobic degradation of the PAH naphthalene. Remarkable large hydrogen isotopic enrichment factors contrasted with much smaller values for carbon: ε(H) = -100‰ ± 15‰, ε(C) = -5.0‰ ± 1.0‰ (enrichment culture N47); ε(H) = -73‰ ± 11‰, ε(C) = -0.7‰ ± 0.3‰ (pure culture NaphS2). This reveals a considerable potential of hydrogen isotope analysis to assess anaerobic degradation of PAHs. Furthermore, we investigated the conclusiveness of dual isotope fractionation to characterize anaerobic aromatics degradation. C and H isotope fractionation during benzene degradation (ε(C) = -2.5‰ ± 0.2‰; ε(H) = -55‰ ± 4‰ (sulfate-reducing strain BPL); ε(C) = -3.0‰ ± 0.5‰; ε(H) = -56‰ ± 8‰ (iron-reducing strain BF)) resulted in dual isotope slopes (Λ = 20 ± 2; 17 ± 1) similar to those reported for nitrate-reducers. This breaks apart the current picture that anaerobic benzene degradation by facultative anaerobes (denitrifiers) can be distinguished from that of strict anaerobes (sulfate-reducers, fermenters) based on the stable isotope enrichment factors. AU - Bergmann, F.D. AU - Abu Laban, N.M.F.H. AU - Meyer, A.H. AU - Elsner, M. AU - Meckenstock, R.U. C1 - 6535 C2 - 28918 SP - 6947-6953 TI - Dual (C, H) isotope fractionation in anaerobic low molecular weight (poly)aromatic hydrocarbon (PAH) degradation: Potential for field studies and mechanistic implications. JO - Environ. Sci. Technol. VL - 45 IS - 16 PB - American Chemical Society PY - 2011 SN - 0013-936X ER - TY - JOUR AB - Enzymatic activities involved in decay processes of natural aromatic macromolecules, such as humic acids (HA) and lignin by white rot fungi, have been widely investigated. However, the physical and chemical analysis of degradation products of these materials has not been intensively explored. Fourier transform cyclotron resonance mass spectrometry (FTICR MS) and 1H NMR as well as CHNOS and size exclusion chromatography were employed to study the mechanisms of HA degradation by Trametes sp. M23 and Phanerochaete sp. Y6. Size exclusion chromatography analyses demonstrate and provide evidence for HA breakdown into low MW compounds. The 1H NMR analysis revealed oxidation, a decrease in the aromatic content, and an indication of demethylation of the HA during biodegradation. Evidence for oxidation was also obtained using CHNOS. Analysis of FTICR MS results using a new software program developed by our group (David Mass Sort) revealed consecutive series of masses suggesting biochemical degradation trends such as oxidation, aromatic cleavage, and demethylation. These results are in agreement with the 1H NMR analysis and with the suggested role of the ligninolytic system leading to HA degradation. AU - Grinhut, T.* AU - Hertkorn, N. AU - Schmitt-Kopplin, P. AU - Hadar, Y.* AU - Chen, Y.N.* C1 - 6336 C2 - 27859 SP - 2748-2754 TI - Mechanisms of humic acids degradation by white rot fungi explored using 1H NMR spectroscopy and FTICR mass spectrometry. JO - Environ. Sci. Technol. VL - 45 IS - 7 PB - American Chemical Society PY - 2011 SN - 0013-936X ER - TY - JOUR AB - Anaerobic degradation processes play an important role in contaminated aquifers. To indicate active biodegradation processes signature metabolites can be used. In this study field samples from a high-resolution multilevel well in a tar oil-contaminated, anoxic aquifer were analyzed for metabolites by liquid chromatography-tandem mass spectrometry and time-of-flight mass spectrometry. In addition to already known specific degradation products of toluene, xylenes, and naphthalenes, the seldom reported degradation products benzothiophenemethylsuccinic acid (BTMS), benzofuranmethylsuccinic acid (BFMS), methylnaphthyl-2-methylsuccinic acid (MNMS), and acenaphthene-5-carboxylic acid (AC) could be identified (BFMS, AC) and tentatively identified (BTMS, MNMS). The occurrence of BTMS and BFMS clearly show that the fumarate addition pathway, known for toluene and methylnaphthalene, is also important for the anaerobic degradation of heterocyclic contaminants in aquifers. The molar concentration ratios of metabolites and their related parent compounds differ over a wide range which shows that there is no simple and consistent quantitative relation. However, generally higher ratios were found for the more recalcitrant compounds, which are putatively cometabolically degraded (e.g., 2-carboxybenzothiophene and acenaphthene-5-carboxylic acid), indicating an accumulation of these metabolites. Vertical concentration profiles of benzylsuccinic acid (BS) and methyl-benzylsuccinic acid (MBS) showed distinct peaks at the fringes of the toluene and xylene plume indicating hot spots of biodegradation activity and supporting the plume fringe concept. However, there are some compounds which show a different vertical distribution with the most prominent concentrations where also the precursor compounds peaked. AU - Jobelius, C.* AU - Ruth, B. AU - Griebler, C. AU - Meckenstock, R.U. AU - Hollender, J.* AU - Reineke, A.* AU - Frimmel, F.H.* AU - Zwiener, C.* C1 - 6089 C2 - 28051 CY - Washington, DC SP - 474-481 TI - Metabolites indicate hot spots of biodegradation and biogeochemical gradients in a high-resolution monitoring well. JO - Environ. Sci. Technol. VL - 45 IS - 2 PB - American Chemical Society PY - 2011 SN - 0013-936X ER - TY - JOUR AB - Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 ((131)I) and cesium isotopes ((137)Cs and (134)Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous (131)I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous (131)I and the large underestimation of the total (131)I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous (131)I fraction to total (131)I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the (134)Cs to (137)Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total (131)I inventory that has passed over Europe during this period was <1% of the released amount. According to the measurements, airborne activity levels remain of no concern for public health in Europe. AU - Masson, O.* AU - Baeza, A.* AU - Bieringer, J.* AU - Brudecki, K.* AU - Bucci, S.* AU - Cappai, M.* AU - Carvalho, F.P.* AU - Connan, O.* AU - Cosma, C.* AU - Dalheimer, A.* AU - Didier, D.* AU - Depuydt, G.* AU - de Geer, L.E.* AU - de Vismes, A.* AU - Gini, L.* AU - Groppi, F.* AU - Gudnason, K.* AU - Gurriaran, R.* AU - Hainz, D.* AU - Halldórsson, Ó.* AU - Hammond, D.* AU - Hanley, O.* AU - Holeý, K.* AU - Homoki, Z.* AU - Ioannidou, A.* AU - Isajenko, K.* AU - Jankovic, M.* AU - Katzlberger, C.* AU - Kettunen, M.* AU - Kierepko, R.* AU - Kontro, R.* AU - Kwakman, P.J.* AU - Lecomte, M.* AU - Leon Vintro, L.* AU - Leppänen, AP.* AU - Lind, B.* AU - Lujaniene, G.* AU - Mc Ginnity, P.* AU - Mc Mahon, C.* AU - Malá, H.* AU - Manenti, S.* AU - Manolopoulou, M.* AU - Mattila, A.* AU - Mauring, A.* AU - Mietelski, J.W.* AU - Møller, B.* AU - Nielsen, S.P.* AU - Nikolic, J.* AU - Overwater, R.M.* AU - Pálsson, S.E.* AU - Papastefanou, C.* AU - Penev, I.* AU - Pham, M.K.* AU - Povinec, P.P.* AU - Ramebäck, H.* AU - Reis, M.C.* AU - Ringer, W.* AU - Rodriguez, A.* AU - Rulík, P.* AU - Saey, P.R.* AU - Samsonov, V.* AU - Schlosser, C.* AU - Sgorbati, G.* AU - Silobritiene, B.V.* AU - Söderström, C.* AU - Sogni, R.* AU - Solier, L.* AU - Sonck, M.* AU - Steinhauser, G.* AU - Steinkopff, T.* AU - Steinmann, P.* AU - Stoulos, S.* AU - Sýkora, I.* AU - Todorovic, D.* AU - Tooloutalaie, N.* AU - Tositti, L.* AU - Tschiersch, J. AU - Ugron, A.* AU - Vagena, E.* AU - Vargas, A.* AU - Wershofen, H.* AU - Zhukova, O.* C1 - 6603 C2 - 28967 CY - Washington, DC SP - 7670-7677 TI - Tracking of airborne radionuclides from the damaged Fukushima Dai-ichi nuclear reactors by European networks. JO - Environ. Sci. Technol. VL - 45 IS - 18 PB - American Chemical Society PY - 2011 SN - 0013-936X ER - TY - JOUR AB - The impact of bacteria-solid and bacteria-bacteria interactions on the transport of Klebsiella oxytoca, Burkholderia cepacia G4PR1, and Pseudomonas sp. #5 was investigated in saturated sand column experiments (L = 114 mm; circle divide = 33 mm) under constant water velocities (similar to 5 cm . h(-1)). Bacterial strains were injected into the columns as pulses either individually, simultaneously, or successively. A one-dimensional mathematical model for advective-dispersve transport and for irreversible and reversible bacterial kinetic sorption was used to analyze the bacterial breakthrough Different sorption parameters were obtained for each strain in each of the three experimental setups. In the presence of other bacteria, sorption parameters for B. cepacia G4PR1 remained similar to results from individual experiments, indicating the presence of other,. bacteria generally had a lesser influence on its migration than for the other bacteria K oxytoca is more competitive for the sorption, sites when simultaneously injected with the I other bacteria. Ps. sp. #5 generally yielded the greatest detachment rates and the least affinity to attach to the sand, indicative of its mobility in groundwater systerns. The results of this study clearly indicate both bacteria-solid and bacteria bacteria interactions influence the migration of bacteria. A more complete understanding of such interactions is necessary to determine potential migration in groundwater systems. AU - Stumpp, C. AU - Lawrence, J.R.* AU - Hendry, M.J.* AU - Maloszewski, P. C1 - 5432 C2 - 28456 CY - Washington, USA SP - 2116-2123 TI - Transport and bacterial interactions of three bacterial strains in saturated column experiments. JO - Environ. Sci. Technol. VL - 45 IS - 6 PB - Amer. Chemical Soc. PY - 2011 SN - 0013-936X ER - TY - JOUR AB - Toxicological studies have provided evidence of the toxicity of ultrafine particles (UFP), but epidemiological evidence for health effects of ultrafines is limited. No quantitative summary currently exists of concentration-response functions for ultrafine particles that can be used in health impact assessment. The goal was to specify concentration-response functions for ultrafine particles in urban air including their uncertainty through an expert panel elicitation. Eleven European experts from the disciplines of epidemiology, toxicology, and clinical medicine selected using a systematic peer-nomination procedure participated. Using individual ratings supplemented with group discussion, probability distributions of effect estimates were obtained for all-cause mortality and cardiovascular and respiratory hospital admissions. Experts judged the small database of epidemiological studies supplemented with experimental studies sufficient to quantify effects of UFP on all-cause mortality and to a lesser extent hospital admissions. Substantial differences in the estimated UFP health effect and its uncertainty were found between experts. The lack of studies on long-term exposure to UFP was rated as the most important source of uncertainty. Effects on hospital admissions were considered more uncertain. This expert elicitation provides the first quantitative evaluation of estimates of concentration response functions between urban air ultrafine particles and all-cause mortality and hospital admissions. AU - Hoek, G.* AU - Boogaard, H.* AU - Knol, A.* AU - de Hartog, J.* AU - Slottje, P.* AU - Ayres, J.G.* AU - Borm, P.* AU - Brunekreef, B.* AU - Donaldson, K.* AU - Forastiere, F.* AU - Holgate, S.* AU - Kreyling, W.G. AU - Nemery, B.* AU - Pekkanen, J.* AU - Stone, V.* AU - Wichmann, H.-E. AU - van der Sluijs, J.* C1 - 711 C2 - 27076 SP - 476-482 TI - Concentration response functions for ultrafine particles and all-cause mortality and hospital admissions: Results of a European expert panel elicitation. JO - Environ. Sci. Technol. VL - 44 IS - 1 PB - American Chemical Society PY - 2010 SN - 0013-936X ER - TY - JOUR AB - Site-specific isotopic values of methyl tertiary butyl ether (MTBE) were measured using quantitative site-specific (2)H nuclear magnetic resonance (NMR) spectroscopy for seven commercially available MTBE products. The delta(2)H values of the methoxy and tertiary butyl groups ranged from -103 per thousand to -171 per thousand, and from -76 per thousand to -104 per thousand, reflecting their production from methanol and isobutene, respectively. Several MTBE products whose whole-compound delta(13)C and delta(2)H MTBE values were within error of each other, as measured by isotope ratio mass spectrometry (IRMS), had demonstrably different delta(2)H values for their methoxy and tertiary butyl groups measured by (2)H NMR. Site-specific isotopic variations were large enough to provide proof of principle that quantitative site-specific (2)H NMR may provide an additional parameter for contaminant sourcing at field sites. Isotopic variations were small enough to not bias the comparability of degradation-associated isotopic enrichment factors determined using different MTBE products. Calculated delta(2)H values for MTBE, derived as weighted averages of (2)H NMR measurements of the two functional groups, showed good agreement with IRMS measurements. The ability to gain accurate information about the site-specific isotopic ratios of (2)H/(1)H within a molecule offers considerable promise as a new environmental tool to track the source and fate of environmental contaminants. AU - McKelvie, J.R.* AU - Elsner, M. AU - Simpson, A.J.* AU - Lollar, B.S.* AU - Simpson, M.J.* C1 - 3417 C2 - 27782 SP - 1062-1068 TI - Quantitative site-specific ²H NMR investigation of MTBE: Potential for assessing contaminant sources and fate. JO - Environ. Sci. Technol. VL - 44 IS - 3 PB - American Chemical Society PY - 2010 SN - 0013-936X ER - TY - JOUR AB - The fate of pesticides in the subsurface is of great interest to the public, industry, and regulatory authorities. Compound-specific isotope analysis (CSIA) is a promising tool complementary to existing methods for elucidating pesticide degradation reactions. Here, we address three different initial biotransformation reactions of the phenylurea herbicide isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) in pure culture experiments with bacterial and fungal strains. When analyzing isotopic changes in different parts of the isoproturon molecule, hydroxylation of the isopropyl group by fungi was found to be associated with C and H isotope fractionation. In contrast, hydrolysis by Arthrobacter globiformis D47 caused strong C and N isotope fractionation, albeit in a different manner than abiotic hydrolysis so that isotope measurements can distinguish between both modes of transformation. No significant isotope fractionation was observed during N-demethylation by Sphingomonas sp. SRS2. The observed isotope fractionation patterns were in agreement with the type of reactions and elements involved. Moreover, their substantially different nature suggests that isotope changes in natural samples may be uniquely attributed to either pathway, allowing even to distinguish the abiotic versus biotic nature of hydrolysis. Our investigations show how characteristic isotope patterns may significantly add to the present understanding of the environmental fate of pesticides. AU - Penning, H. AU - Sørensen, S.R.* AU - Meyer, A.H. AU - Aamand, J.* AU - Elsner, M. C1 - 3011 C2 - 27185 SP - 2372-2378 TI - C, N, and H isotope fractionation of the herbicide isoproturon reflects different microbial transformation pathways. JO - Environ. Sci. Technol. VL - 44 IS - 7 PB - American Chemical Society PY - 2010 SN - 0013-936X ER - TY - JOUR AB - Flow-through experiments were carried out to investigate the role of transverse dispersion on the isotopic behavior of an organic compound during conservative and bioreactive transport in a homogeneous porous medium. Ethylbenzene was selected as model contaminant and a mixture of labeled (perdeuterated) and light isotopologues was continuously injected in a quasi two-dimensional flow-through system. We observed a significant fractionation of ethylbenzene isotopologues during conservative transport at steady state. This effect was particularly pronounced at the plume fringe and contrasted with the common assumption that physical processes only provide a negligible contribution to isotope fractionation. Under the experimental steady state conditions, transverse hydrodynamic dispersion was the only process that could have caused the observed fractionation. Therefore, the measured isotope ratios at the outlet ports were interpreted with different parameterizations of the transverse dispersion coefficient. A nonlinear compound-specific parameterization showed the best agreement with the experimental data. Successively, bioreactive experiments were performed in two subsequent stages: a first oxic phase, involving a single strain of ethylbenzene degraders and a second phase with aerobic and anaerobic (i.e., ethylbenzene oxidation coupled to nitrate reduction) degradation. Significant fractionation through biodegradation occurred exclusively due to the metabolic activity of the anaerobic degraders. We performed analytical and numerical reactive transport simulations of the different experimental phases which confirmed that both the effects of physical processes (diffusion and dispersion) and microbially mediated reactions have to be considered to match the observed isotopic fractionation behavior. AU - Rolle, M.* AU - Chiogna, G.* AU - Bauer, R.D. AU - Griebler, C. AU - Grathwohl, P.* C1 - 2595 C2 - 27452 SP - 6167-6173 TI - Isotopic fractionation by transverse dispersion: Flow-through microcosms and reactive transport modeling study. JO - Environ. Sci. Technol. VL - 44 IS - 16 PB - American Chemical Society PY - 2010 SN - 0013-936X ER - TY - JOUR AB - The effects of low NO2(-) concentrations on stable isotope fractionation during dissimilatory sulfate reduction by strain Desulfovibrio desulfuricans were investigated. Nitrite, formed as an intermediate during nitrification and denitrification processes in marine and freshwater habitats, inhibits the reduction of the sulfuroxy intermediate SO3(2-) to H2S even at low concentrations. To gain an understanding of the inhibition effect of the reduction of the sulfuroxy intermediate on stable isotope fractionation in sulfur and oxygen during bacterial sulfate reduction, nitrite was added in the form of short pulses. In the batch experiments that contained 0.02, 0.05, and 0.1 mM nitrite, sulfur enrichment factors epsilon of -12 +/- 1.6, -15 +/- 1.1, and -26 +/- 1.3 per thousand, respectively were observed. In the control experiment (no addition of nitrite) a sulfur enrichment factor epsilon of around -11 per thousand was calculated. In the experiments that contained no 18O enriched water (delta18O: -10 per thousand) and nitrite concentrations of 0.02, 0.05, and 0.1 mM, delta18O values in the remaining sulfate were fairly constant during the experiments (delta18O sulfate: approximately equal to 10 per thousand) and were similar to those obtained from the control experiment (no nitrite and no enriched water). However, in the batch experiments that contained 18O enriched water (+700 per thousand) and nitrite concentrations of 0.05 and 0.1 mM increasing delta18O values in the remaining sulfate from around 15 per thousand to approximately 65 and 85 per thousand, respectively, were found. Our experiments that contained isotopic enriched water and nitrite show clear evidence that the ratio of forward and backward fluxes regulated by adenosine-5'-phosphosulfate reductase (APSR) controls the extent of sulfur isotope fractionation during bacterial sulfate reduction in strain Desulfovibrio desulfuricans. Since the metabolic sulfuroxy intermediate SO3(2-) exchanges with water, evidence of 18O enriched water in the remaining sulfate in the experiments that contained nitrite also demonstrates that SO3(2-) recycling to sulfate affects sulfur and oxygen isotope fractionation during bacterial sulfate reduction to some extent. Even though reduction of adenosine-5'-phosphosulfate (APS) to sulfite of -25 per thousand was not fully expressed, SO3(2-) was recycled to SO4(2-). On the basis of the results of this study a sulfur isotope fractionation for APSR of upto approximately -30 per thousand can be assumed. However, reported NO2(-) concentrations of up to 20 microM in freshwater and marine habitats may not significantly impact the ability to use stable isotope analysis in assessing bacterial sulfate reduction. AU - Einsiedl, F. C1 - 1295 C2 - 25975 SP - 82-87 TI - Effect of NO₂⁃on stable isotope fractionation during bacterial sulfate reduction. JO - Environ. Sci. Technol. VL - 43 IS - 1 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - This study explored them potential of eutrophic river sediment to attenuate the infiltration of chlorinated aliphatic hydrocarbon (CAH)- polluted groundwater discharging into the Zenne River near Brussels, Belgium. Active CAH biodegradation by reductive dechlorination in the sediment was suggested by a high dechlorination activity in microcosms containing sediment samples and the detection of dechlorination products in sediment pore water. A unique hydrogeochemical evaluation, including a delta H-2 and delta O-18 stable isotope approach, allowed to determine the contribution of different abiotic and biotic CAH attenuation processes and to delineate their spatial distribution in the riverbed. Reductive dechlorination of the CAHs seemed to be the most widespread attenuation process, followed by dilution by unpolluted groundwater. discharge and by surface water mixing. Although CAHs were never detected in tie surface water, 26-28% of the investigated locations in the riverbed did not show CAH attenuation. We conclude that the. riverbed sediments can attenuate infiltrating CAHs to a certain extent, but will probably not completely prevent CAHs to discharge from the contaminated groundwater into the Zenne River. AU - Hamonts, K.* AU - Kuhn, T.K. AU - Maesen, M.* AU - Bronders, J.* AU - Lookman, R.* AU - Kalka, H.* AU - Diels, L.* AU - Meckenstock, R.U. AU - Springael, D.* AU - Dejonghe, W.* C1 - 2842 C2 - 26828 SP - 5270-5275 TI - Factors determining the attenuation of chlorinated aliphatic hydrocarbons in eutrophic river sediment impacted by discharging polluted groundwater. JO - Environ. Sci. Technol. VL - 43 IS - 14 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - There is increasing interest in combined carbon-chlorine compound-specific isotope analysis (CSIA) to differentiate between contaminant sources and to assess transformation processes, However, the significant abundance of polychlorinated molecules with several heavy chlorine isotopes complicates the evaluation of chlorine isotope trends. Therefore, the goal of this study was to develop a conceptual and mathematical framework that describes the expected chlorine isotope fractionation patterns during multistep transformation of chlorinated compounds. Reductive dechlorination of chlorinated ethenes served as an example. The study demonstrates that chlorine isotope trends can be simulated by reproducing the average behavior of light and heavy isotopes or by explicitly simulating molecules with different numbers of heavy isotopes (isotopologues). The calculations reveal that initial chlorine isotope ratios of products equal the isotope ratios of their parent compounds in the absence of secondary isotope effects, while steadily increasing during transformation. The slopes in dual isotope plots are linear for reactant and product during a one-step reaction. They become nonlinear for products that are degraded further but converge to characteristic slopes. Consideration of different scenarios reveals that combined carbon-chlorine isotope analysis bears high potential to differentiate between contaminant sources, to elucidate reaction mechanisms in laboratory studies, and to identify transformation processes in the field. AU - Hunkeler, D.* AU - van Breukelen, B.M.* AU - Elsner, M. C1 - 966 C2 - 26773 CY - WASHINGTON SP - 6750-6756 TI - Modelling chlorine isotope trends during sequential transformation of chlorinated ethenes. JO - Environ. Sci. Technol. VL - 43 IS - 17 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - At a field site in the industrial area of Vilvoorde, Belgium, we investigated the capacity of the indigenous microbial community of a eutrophic river sediment to biodegrade chlorinated aliphatic hydrocarbons (CAHs) originating from discharging, polluted groundwater using a compound-specific isotope approach. We specifically targeted the site's major pollutants cis-1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Analysis of Rayleigh correlation plots enabled us to assess the Went to which microbial and abiotic natural attenuation processes contributed to the mitigation of a pollution of the surface water due to discharging CAH-contaminated groundwater. Our results provide evidence for (i) the occurrence of biodegradation of cis-DCE and VC by reductive dechlorination in parts of the aquifer and at several positions in the river sediment, (ii) the presence of river sediment zones exhibiting attenuation of chloroethenes by a combination of biodegradation and dilution through unpolluted water, (iii) the existence of zones in the river sediment lacking significant biodegradation, and thus (iv) a pronounced spatial heterogeneity in the occurrence and extent of biodegradation in the aquifer and river sediment, We conclude that at many investigated positions in the river sediment the indigenous microbial community failed to facilitate complete biodegradation of the groundwater-sourced chloroethenes. The overall intrinsic bioremediation capacity of the river sediment was thus not high enough to completely prevent the release of these pollutants into the surface water. These findings and conclusions are thus in agreement with those of our companion paper ( 1), which investigated the river sediments at the Vilvoorde study site by a combination of stable hydrogen and oxygen isotope analysis of water and the detection of chlorinated aliphatic hydrocarbons (CAHs) and their dechlorination products. AU - Kuhn, T.K. AU - Hamonts, K.* AU - Dijk, J.A.* AU - Kalka, H.* AU - Stichler, W. AU - Springael, D.* AU - Dejonghe, W.* AU - Meckenstock, R.U. C1 - 1689 C2 - 26988 SP - 5263-5269 TI - Assessment of the intrinsic bioremediation capacity of an eutrophic river sediment polluted by discharging chlorinated aliphatic hydrocarbons: A compound-specific isotope approach. JO - Environ. Sci. Technol. VL - 43 IS - 14 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - Carbon isotopic enrichment factors (epsilon(c)) measured during cometabolic biodegradation of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) by Pseudonocardia tetrahydrofuranoxydans strain K1 were -2.3 +/- 0.2 parts per thousand, -1.7 +/- 0.2 parts per thousand, and -1.7 0.3 parts per thousand, respectively. The measured carbon apparent kinetic isotope effect was 1.01 for all compounds, consistent with the expected kinetic isotope effects for both oxidation of the methoxy(or ethoxy) group and enzymatic S(N)1 biodegradation mechanisms. Significantly, delta C-13 measurements of the tert-butyl alcohol and tert-amyl alcohol products indicated that the tert-butyl and tert-amyl groups do not participate in the reaction and confirmed that ether biodegradation by strain K1 involves oxidation of the methoxy (or ethoxy) group. Measured hydrogen isotopic enrichment factors (CH) were -100 +/- 10 parts per thousand, -73 +/- 7 parts per thousand, and -72 +/- 2 parts per thousand for MTBE, ETBE, and TAME respectively. Previous results reported for aerobic biodegradation of MTBE by Methylibium petroleiphilum PM1 and Methylibium R8 showed smaller EH values (-35 parts per thousand and -42 parts per thousand, respectively. Plots of Delta H-2/Delta C-13 show different slopes for strain K1 compared with strains PM1 and 138, suggesting that different mechanisms are utilized by K1 and PM1/R8 during aerobic MTBE biodegradation. AU - McKelvie, J.R.* AU - Hyman, M.R.* AU - Elsner, M. AU - Smith, C.* AU - Aslett, D.M.* AU - Lacrampe-Couloume, G.* AU - Lollar, B.S.* C1 - 1101 C2 - 26177 SP - 2793-2799 TI - Isotopic fractionation of methyl tert-butyl ether suggests different initial reaction mechanisms during aerobic biodegradation. JO - Environ. Sci. Technol. VL - 43 IS - 8 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - Transformation of atrazine to hydroxyatrazine in the environment may be underestimated by current assessment schemes since immobilization and further transformation of the metabolite can render parent-to-daughter compound ratios unreliable. This study reports significant C and N isotope fractionation of atrazine in transformation to hydroxyatrazine by Chelatobacter heintzii, Pseudomonas sp. ADP, and Arthrobacter aurescens M highlighting an alternative approach to detecting this natural transformation pathway. Indistinguishable dual isotope slopes Delta (= delta N-15/delta C-13 approximate to epsilon(N)/epsilon(C)) for Chelatobacter heintzii (-0.65 +/- 0.08) and Arthrobacter aurescens TC1 (-0.61 +/- 0.02) suggest the same biochemical transformation mechanism despite different hydrolyzing enzymes (AtzA versus TrzN). With Pseudomonas sp. ADP (also AtzA) significantly smaller fractionation indicates masking effects by steps prior to enzyme catalysis, while a distinguishable Delta = -0.32 +/- 0.06 suggests that some of these steps showed slight isotope fractionation. Abiotic reference experiments reproduced the pattern of biotic transformation at pH 3 (enrichment of C-13, depletion of N-15 in atrazine), but showed enrichment of both C-13 and N-15 at pH 12. This indicates that the organisms activated atrazine by a similar Lewis acid complexation (e.g., with H+) prior to nucleophilic aromatic substitution, giving the first detailed mechanistic insight into this important enzymatic reaction. AU - Meyer, A.H. AU - Penning, H. AU - Elsner, M. C1 - 751 C2 - 26774 CY - Washington SP - 8079-8085 TI - C and N isotope fractionation suggests similar mechanisms of microbial atrazine transformation despite involvement of different enzymes (AtzA and TrzN). JO - Environ. Sci. Technol. VL - 43 IS - 21 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - A high spatial resolution data set documenting carbon and sulfur isotope fractionation at a tar oil-contaminated, sulfate-reducing field site was analyzed with a reactive transport model. Within a comprehensive numerical model, the study links the distinctive observed isotope depth profiles with the degradation of various monoaromatic and polycyclic aromatic hydrocarbon compounds (BTEX/PAHs) under sulfate-reducing conditions. In the numerical model, microbial dynamics were simulated explicitly and isotope fractionation was directly linked to the differential microbial uptake of lighter and heavier carbon isotopes during microbial growth. Measured depth profiles from a multilevel sampling well with high spatial resolution served as key constraints for the parametrization of the model simulations. The results of the numerical simulations illustrate particularly well the evolution of the isotope signature of toluene, which is the most rapidly degrading compound and the most important reductant at the site. The resulting depth profiles at the observation well show distinct differences between the small isotopic enrichment in the contaminant plume core and the much stronger enrichment of up to 3.3‰ at the plume fringes. AU - Prommer, H.* AU - Anneser, B. AU - Rolle, M.* AU - Einsiedl, F.* AU - Griebler, C. C1 - 2082 C2 - 26568 CY - Washington SP - 8206-8212 TI - Biogeochemical and isotopic gradients in a BTEX/PAH contaminant plume: Model-based interpretation of a high-resolution field data set. JO - Environ. Sci. Technol. VL - 43 IS - 21 PB - American Chemical Society PY - 2009 SN - 0013-936X ER - TY - JOUR AB - Information on the density (p) and refractive index m(=n-ik) of elemental carbon (ECa) and organic matter (OMa), the main carbon components of atmospheric aerosols, has frequently been obtained from closure calculations between physical and chemical aerosol properties. However, this approach has suffered from large uncertainties since there were more unknown (or poorly known) parameters than defining equations. In this study, we propose a method that avoids this ambiguity mainly by considering both optical and mass closure and by expressing the three ECa parameters (p(Eca), n(Eca), k(ECa)) by a single (unknown) parameter. This allows mathematically rigorous determination of p(Eca), m(Eca), p(OMa) and m(OMa) from standard physico-chemical aerosol data and rigorous error analysis. The results are unambiguous and self-consistent, i.e., there is no difference between the chemically and physically derived p and m values of the atmospheric aerosol. Application of this method to our previously published data on biomass burning particles from Amazonia yields p(Eca) = 1.8(+/- 0.2) g/cm(3), m(ECa) = 1.9(+/- 0.1)-i0.20(-0.04/+0.02), p(OMa) = 1.39(+/- 0.13) g/cm(3) and m(OMa)=1.46(+/- 0.02), where the 1 sigma uncertainty limits given in parenthesis are based on the principles of error propagation. The relatively low imaginary part of mEca indicates the presence of only partially graphitized elemental carbon, which is consistent with biomass burning aerosol dominated bysmoldering combustion conditions. AU - Schmid, O.* AU - Chand, D.* AU - Karg, E.W. AU - Guyon, P.* AU - Frank, G.P.* AU - Swietlicki, E.* AU - Andreae, M.O.* C1 - 427 C2 - 26423 SP - 1166-1172 TI - Derivation of the density and refractive index of organic matter and elemental carbon from closure between physical and chemical aerosol properties. JO - Environ. Sci. Technol. VL - 43 IS - 4 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - The present study investigated the distribution, transportation, and biodegradation of the selected chiral persistent organochlorine pesticides (OCP) in the Alps. In the complex environment, we found the movement and fate of OCP could be defined by many factors. Taking HCE as an example, below the timberline its accumulation from air into SPMD increased with altitude and seasonally changed, but the trends reversed above the timberline. In soil, the tendency of HCE concentrations vs organic materials followed a sigmoid curve, and HCE concentration-altitude correlations are positive in central Alps but negative in southern Alps. The HCE enantiomeric ratios (ERs) in soil correlated to HCE isomers concentrations, the humus pH values, and the sampling site altitudes. HCE shift from humus to mineral soil can also be traced by ERs. The altitudinal and longitudinal trends in needles suggested that (alpha-HCH has a more complex movement than HCE in Alps. In conclusion, altitude conducted condensation, plant canopies, organic material in soil, and geographic specific precipitations may affect OCP distributions and transportation, whereas altitude conducted temperature and soil pH could dictate their fate in the environment. AU - Shen, H. AU - Henkelmann, B. AU - Levy, W. AU - Zsolnay, A. AU - Weiss, P.* AU - Jakobi, G. AU - Kirchner, M. AU - Moche, W.* AU - Braun, K.* AU - Schramm, K.-W. C1 - 2234 C2 - 26233 SP - 2450-2455 TI - Altitudinal and chiral signature of persistent organochlorine pesticides in air, soil, and spruce needles (Picea abies) of the Alps. JO - Environ. Sci. Technol. VL - 43 IS - 7 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - Humic substances (HS) and quinones can accelerate dissimilatory Fe(III) reduction by electron shuttling between microorganisms and poorly soluble iron(III) (hydr)oxides. The mechanism of electron shuttling for HS is not fully understood, but it is suggested that the most important redox-active components in HS are also quinones. Here we studied the influence of HS and different quinones at low concentrations on ferrihydrite reduction by Geobacter metallireducens. The aquatic HS used were humic and fulvic acids (HA and FA) isolated from groundwater of a deep aquifer in Gorleben (Niedersachsen, Germany). HA stimulated iron reduction stronger than FA down to total HA concentrations as low as 1 mg/L. The quinones studied showed large differences: some had strong accelerating effects, whereas others showed only small effects, no effects, or even inhibitory effects on the kinetics of iron reduction. We found that the redox potentials of the most active quinones fall in a narrow range of -137 to -225 mV vs NHE at pH 7. These results give evidence that the kinetic of microbial iron reduction mediated by electron shuttles is mainly controlled by thermodynamic parameters, i.e., by the redox potential of the shuttle compound, rather than by the proportion of dissolved vs adsorbed compound. AU - Wolf, M. AU - Kappler, A.* AU - Jiang, J.* AU - Meckenstock, R.U. C1 - 1187 C2 - 26359 SP - 5679-5685 TI - Effects of humic substances and quinones at low concentrations on ferrihydrite reduction by Geobacter metallireducens. JO - Environ. Sci. Technol. VL - 43 IS - 15 PB - Amer Chemical Soc PY - 2009 SN - 0013-936X ER - TY - JOUR AB - Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a common contaminant at explosives production sites. Here, we report on the use of compound-specific isotope analysis of RDX to obtain ?15N and ?18O enrichment factors during biodegradation in batch cultures. A new preparation method has been developed based on RDX purification using thin-layer chromatography. RDX is then subjected to an elemental analyzer coupled with an isotope-ratio mass spectrometer (EA-IRMS). The precision of the method shows standard deviations of 0.13‰ and 1.18‰ for ?15N and ?18O, respectively, whereas the accuracy of the method has been checked routinely, adhering to external standards. The method was applied to RDX samples subjected to biodegradation under aerobic or anaerobic conditions. Enrichment factors under aerobic conditions were -2.1‰ and -1.7‰ for ?15N and ?18O, respectively, and under anaerobic conditions, -5.0‰ and -5.3‰ for ?15N and ?18O, respectively. The results of this study provide a tool for monitoring natural attenuation of RDX in a contaminated environment. AU - Bernstein, A.* AU - Ronen, Z.* AU - Adar, E.* AU - Nativ, R.* AU - Lowag, H. AU - Stichler, W. AU - Meckenstock, R.U. C1 - 2926 C2 - 25714 SP - 7772-7771 TI - Compound-specific Isotope analysis of RDX and stable isotope fractionation during aerobic and anaerobic Bbiodegradation. JO - Environ. Sci. Technol. VL - 42 IS - 21 PB - ACS Publ. PY - 2008 SN - 0013-936X ER - TY - JOUR AB - Groundwater samples collected in a shallow oxic and reduced deep groundwater system revealed the influence of dissolved sulfide on the chemical and isotopic composition of fulvic acid associated sulfur. Stable isotope compositions of groundwater sulfate and fulvic acid sulfur and sulfur K-edge X-ray absorption near edge structure (XANES) spectroscopy data were used to determine the sources and processes affecting fulvic acid sulfur in the aquifer. A ?34S value of 2.2 ‰ for the shallow groundwater sulfate and a ?34S value of fulvic acids of 4.9 ‰ accompanied by a contribution of up to 49% of the most oxidized sulfur species (S+6) documented that fulvic acid sulfur is mainly derived from soil S compounds such as ester sulfates, with ?34S values similar to those of atmospheric sulfate deposition. In contrast, in the deep groundwater system with elevated ?34S values in groundwater sulfate of up to 20‰ due to bacterial sulfate reduction, ?34S values in fulvic acid sulfur were negative and were up to 22‰ lower compared to those of groundwater sulfate. Furthermore, reduced sulfur compounds constituted a significantly higher proportion of total fulvic acid sulfur in the deep groundwater compared to fulvic acids in shallow groundwater, supporting the hypothesis that fulvic acids act as a sink for dissolved hydrogen sulfide in the deep aquifer. Our results suggest that the combination of sulfur K edge XANES spectroscopy and stable isotope analysis on fulvic acids represents a powerful tool to elucidate the role of fulvic acids in the sulfur cycle in groundwater. AU - Einsiedl, F. AU - Mayer, B.* AU - Schäfer, T.* C1 - 647 C2 - 25209 SP - 2439-2444 TI - Evidence for incorporation of H2S in groundwater fulvic acids from stable isotope ratios and sulfur K-edge X-ray absorption near edge structure spectroscopy. JO - Environ. Sci. Technol. VL - 42 IS - 1 PB - ACS Publ. PY - 2008 SN - 0013-936X ER - TY - JOUR AB - Carbon isotope fractionation is of great interest in assessing chlorinated ethene transformation by nanoscale zero-valent iron at contaminated sites, particularly in distinguishing the effectiveness of an implemented abiotic degradation remediation scheme from intrinsic biotic degradation. Transformation of trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), and vinyl chloride (VC) with two types of nanoscale iron materials showed different reactivity trends, but relatively consistent carbon isotope enrichment factors (?) of -19.4‰ 1.8‰ (VC), -21.7‰ 1.8‰ (cis-DCE), and -23.5‰ 2.8‰ (TCE) with one type of iron (FeBH), and from -20.9‰ 1.1‰ to -26.5‰ 1.5‰ (TCE) with the other (FeH2). Products of the dichloroelimination pathway (ethene, ethane, and acetylene) were consistently 10‰ more isotopically depleted than those of the hydrogenolysis pathway (cis-DCE from TCE, VC from cis-DCE), displaying a characteristic pattern that may serve as an indicator of abiotic dehalogenation reactions and as a diagnostic parameter for differentiating the effects of abiotic versus biotic degradation. In contrast, the product-related enrichment factors of each respective pathway varied significantly in different experiments. Because such variation would not be expected for independent pathways with constant kinetic isotope effects, our data give preliminary evidence that the two pathways may share an irreversible first reaction step with subsequent isotopically sensitive branching. AU - Elsner, M. AU - Chartrand, M.* AU - van Stone, N.* AU - Lacrampe-Couloume, G.* AU - Sherwood Lollar, B.* C1 - 2598 C2 - 25496 SP - 5963-5970 TI - Identifying Abiotic Chlorinated Ethene Degradation: Characteristic Isotope Patterns in Reaction Products with Nanoscale Zero-Valent Iron. JO - Environ. Sci. Technol. VL - 42 IS - 16 PB - ACS Publ. PY - 2008 SN - 0013-936X ER - TY - JOUR AB - The initial metabolic reactions for anaerobic benzene biodegradation remain uncharacterized. Isotopic data for carbon and hydrogen fractionation from nitrate-reducing, sulfate-reducing, and methanogenic benzene-degrading enrichment cultures and phylogenic information were used to investigate the initial reaction step in anaerobic benzene biodegradation. Dual parameter plots of carbon and hydrogen isotopic data (deltadelta2H/ deltadelta13C) from each culture were linear, suggesting a consistent reaction mechanism as degradation proceeded. Methanogenic and sulfate-reducing cultures showed consistently higher slopes (m = 29 +/- 2) compared to nitrate-reducing cultures (m = 13 +/- 2) providing evidence for different initial reaction mechanisms. Phylogenetic analyses confirmed that culture conditions were strictly anaerobic, precluding any involvement of molecular oxygen in the observed differences. Using published kinetic data, we explored the possibility of attributing such slopes to reaction mechanisms. The higher slopes found under methanogenic and sulfate-reducing conditions suggest against an alkylation mechanism for these cultures. Observed differences between the methanogenic and nitrate-reducing cultures may not represent distinct reactions of different bonds, but rather subtle differences in relative reaction kinetics. Additional mechanistic conclusions could not be made because kinetic isotope effect data for carboxylation and other putative mechanisms are not available. AU - Mancini, S.A.* AU - Devine, C.E.* AU - Elsner, M. AU - Nandi, M.E.* AU - Ulrich, A.C.* AU - Edwards, E.A.* AU - Lollar, B.S.* C1 - 2564 C2 - 25822 SP - 8290-8296 TI - Isotopic evidence suggests different initial reaction mechanisms for anaerobic benzene biodegradation. JO - Environ. Sci. Technol. VL - 42 IS - 22 PB - American Chemical Society PY - 2008 SN - 0013-936X ER - TY - JOUR AB - Compound-specific stable isotope analysis by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) is increasingly used to assess origin and fate of organic substances in the environment. Although analysis without isotopic discrimination is essential, it cannot be taken for granted for new target compounds. We developed and validated carbon isotope analysis of atrazine, a herbicide widely used in agriculture. Combustion was tested with reactors containing (i) CuO/NiO/Pt operating at 940 °C; (ii) CuO operating at 800 °C; (iii) Ni/NiO operating at 1150 °C and being reoxidized for 2 min during each gas chromatographic run. Accurate and precise carbon isotope measurements were only obtained with Ni/NiO reactors giving a mean deviation ??13C from dual inlet measurements of -0.1-0.2‰ and a standard deviation (SD) of ±0.4‰. CuO at 800 °C gave precise, but inaccurate values (??13C = -1.3‰, SD ±0.4‰), whereas CuO/NiO/Pt reactors at 940 °C gave inaccurate and imprecise data. Accurate (??15N = 0.2‰) and precise (SD ±0.3‰) nitrogen isotope analysis was accomplished with a Ni/NiO-reactor previously used for carbon isotope analysis. The applicability of the method was demonstrated for alkaline hydrolysis of atrazine at 20 °C and pH 12 (nucleophilic aromatic substitution) giving ?carbon = -5.6‰ ± 0.1‰ (SD) and ?nitrogen = -1.2‰ ± 0.1‰ (SD). AU - Meyer, A.H. AU - Penning, H. AU - Lowag, H. AU - Elsner, M. C1 - 3864 C2 - 25712 SP - 7757-7763 TI - Precise and accurate compound specific carbon and nitrogen isotope analysis of atrazine: Critical role of combustion oven conditions. JO - Environ. Sci. Technol. VL - 42 IS - 21 PB - ACS Publ. PY - 2008 SN - 0013-936X ER - TY - JOUR AB - Stable isotope fractionation permits quantifying contaminant degradation in the field when the transformation reaction is associated with a consistent isotope enrichment factor ?. When interpreted in conjunction with dual isotope plots, isotope fractionation is also particularly useful for elucidating reaction mechanisms. To assess the consistency of ? and dual isotope slopes in a two-step reaction, we investigated the abiotic hydrolysis of the herbicide isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) using a fragmentation method that allows measuring isotope ratios in different parts of the molecule. Carbon and nitrogen position-specific isotope fractionation, as well as slopes in dual isotope plots, varied linearly with rate constants kobs depending on the presence of buffers that mediate the initial zwitterion formation. The correlation can be explained by two consecutive reaction steps (zwitterion formation followed by dimethylamine elimination) each of which has a different kinetic isotope effect and may be rate-limiting. Intrinsic isotope effects for both steps, extracted from our kinetic data using a novel theoretical treatment, agree well with values computed from density functional calculations. Our study therefore demonstrates that more variable isotope fractionation may be observed in simple chemical reactions than commonly thought, but that consistent ? or dual isotope slopes may nonetheless be encountered in certain molecular fragments. AU - Penning, H. AU - Cramer, C.J. AU - Elsner, M. C1 - 3865 C2 - 25713 SP - 7764-7771 TI - Rate-dependent carbon and nitrogen kinetic Isotope fractionation in hydrolysis of isoproturon. JO - Environ. Sci. Technol. VL - 42 IS - 21 PB - ACS Publ. PY - 2008 SN - 0013-936X ER - TY - JOUR AB - The apparent particle density of particulate matter with aerodynamic diameter < 2.5 microm (rho2.5) was determined at an urban site in Augsburg, Germany and its correlation with chemical composition and meteorological conditions was investigated. rho2.5 showed strong day-to-day variation from 1.05 to 2.36 g cm(-3) (5 to 95% percentile), and nearly 64% of the daily variability could be explained by a multiple variable regression model. A minimum in the morning and afternoon (about 1.5 g cm(-3)), and a maximum (near 1.8 g cm(-3)) during midday was observed. The minima represent fresh primary aerosol emissions, which were related to traffic soot particles with low density due to their agglomerate structure, especially observed in the early morning hours of weekdays. The maximum is likely due to increased secondary particle production and the presence of more aged particles with the built-up of the convectively mixed boundary layer. rho2.5 has the potential to serve as a crude tracer for chemical composition and atmospheric processing and might play an important role when considering the associations between health effects and ambient particles. AU - Pitz, M. AU - Schmid, O. AU - Heinrich, J. AU - Birmili, W.* AU - Maguhn, J. AU - Zimmermann, R. AU - Wichmann, H.-E. AU - Peters, A. AU - Cyrys, J. C1 - 2450 C2 - 25584 SP - 5087-5093 TI - Seasonal and diurnal variation of PM2.5 apparent particle density in urban air in Augsburg, Germany. JO - Environ. Sci. Technol. VL - 42 IS - 14 PB - ACS Publ PY - 2008 SN - 0013-936X ER - TY - JOUR AB - Degradation of 1,1- and 1,2-dichloroethane (1,1-DCA, 1,2-DCA) and carbon tetrachloride (CCl4) on Zn0 was investigated using compound specific isotope analysis (CSIA) to measure isotopic fractionation factors for chloroalkane degradation by hydrogenolysis, by ?-elimination, and by ?-elimination. Significant differences in enrichment factors (?) and associated apparent kinetic isotope effects (AKIE) were measured for these different reaction pathways, suggesting that carbon isotope fractionation by ?-elimination is substantially larger than fractionation by hydrogenolysis or by ?-elimination. Specifically, for 1,1-DCA, the isotopic composition of the reductive ?-elimination product (ethane) and the hydrogenolysis product (chloroethane) were the same, indicating that cleavage of a single C-Cl bond was the rate-limiting step in both cases. In contrast, for 1,2-DCA, ? = ?reactive position = -29.7 ± 1.5‰, and the calculated AKIE (1.03) indicated that ?-elimination was likely concerted, possibly involving two C-Cl bonds simultaneously. Compared to 1,1-DCA hydrogenolysis, the AKIE of 1.01 for hydrogenolysis of CCl4 was much lower, indicating that, for this highly reactive organohalide, mass transfer to the surface was likely partially rate-limiting. These findings are a first step toward delineating the relative contribution of these competing pathways in other abiotic systems such as the degradation of chlorinated ethenes on zerovalent iron (ZVI), iron sulfide, pyrite, or magnetite, and, potentially, toward distinguishing between degradation of chlorinated ethenes by abiotic versus biotic processes. AU - van Stone, N.* AU - Elsner, M. AU - Lacrampe-Couloume, G.* AU - Mabury, S.* AU - Sherwood Lollar, B.* C1 - 4278 C2 - 25112 SP - 126-132 TI - Potential for identifying abiotic chloroalkane degradation mechanisms using carbon isotopic fractionation. JO - Environ. Sci. Technol. VL - 42 PB - ACS Publ. PY - 2008 SN - 0013-936X ER - TY - JOUR AB - The interior of motor vehicles is made of a wide variety of synthetic materials, which emit volatile organic compounds (VOC). We tested the health effects of emissions from vehicles exposed to "parked in sunshine" conditions. A new and a 3 year old vehicle with identical interior were exposed to 14 000 W of light. Indoor air was analyzed by GC-MS. Toxicity of extracts of indoor air was assayed in human primary keratinocytes, human lung epithelial A549 cell line, and Chinese hamster V79 lung fibroblasts. In addition, toxicity after metabolic activation by CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, and CYP2E1 was assayed. The effect on type I allergic reaction (IgE-mediated immune response), type IV allergic reaction (T-cell mediated immune response), and irritative potential was evaluated also. A total of 10.9 and 1.2 mg/m(3) VOC were found in new and used motor vehicle indoor air, respectively. The major compounds in the new vehicle were o,m,p-xylenes, C3 and C4-alkylbenzenes, dodecane, tridecane, and methylpyrrolidinone. In the used vehicle they were acetone, methylpyrrolidinone, methylcyclohexane, acetaldehyde, o,m,p-xylenes, ethylhexanol, and toluene. No toxicity was observed in any cell line with or without metabolic activation. Neither did we find an effect on type IV sensitization or an irritative potential. A slight but statistically significant aggravating effect on IgE-mediated immune response of only the new vehicle indoor air was determined (p < 0.05). The IgE-response modulating effect of indoor air might be relevant for atopic individuals. Else no direct toxicity, no toxicity after metabolic activation by cytochrome P450, and no irritative or type IV sensitizing potential of motor vehicle indoor air were found, neither from the new nor used vehicle. Our investigations indicated no apparent health hazard of parked motor vehicle indoor air. AU - Buters, J.T.M. AU - Schober, W. AU - Gutermuth, J. AU - Jakob, T.* AU - Aguilar-Pimentel, J.A. AU - Huss-Marp, J. AU - Traidl-Hoffmann, C. AU - Mair, S.* AU - Mayer, F.* AU - Breuer, K.* AU - Behrendt, H. C1 - 1342 C2 - 24725 SP - 2622-2629 TI - Toxicity of parked motor vehicle indoor air. JO - Environ. Sci. Technol. VL - 41 IS - 7 PB - ACS Publ. PY - 2007 SN - 0013-936X ER - TY - JOUR AB - Despite widespread implementation of zero-valent iron remediation schemes, the manner and order of chemical bond cleavage in iron-mediated organohalide transformations remains imperfectly understood. We present insights from carbon isotope fractionation for the dehalogenation of 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA) and 1,1,1-trichloroethane (1,1,1-TCA) by various reactants. Elimination of HCl by OH- gave isotope fractionation in 1,1,2,2-TeCA of = -25.6”, KIEC = 1.02 to 1.03 per carbon center, consistent with a concerted (E2) mechanism. In contrast, 1,1,1-TCA reduction by Cr(II), Fe(0), and Cu-plated iron (Cu/Fe) resulted in = -13.6” to -15.8” indicating the initial involvement of a single C-Cl bond (KIEC 1.03). 1,1,2,2-TeCA reduction by Cr(II), Fe(0), and Cu/Fe yielded = -18.7”, -19.3”, and -17.0”, respectively. In the two latter cases, depletion of the minor product TCE by 26” indicated its formation via nonreductive dehydrohalogenation. The major 1,1,2,2-TeCA reduction products, cis- and trans-DCE, differed by 2.3” ± 1.0” in Cr(II) systems, but were equivalent in Fe(0) and Cu/Fe systems. In contrast, the ratio of cis-DCE to trans-DCE concentration was 2.5 for reduction with Cr(II) and Fe(0), but ~3.8 with Cu/Fe. Complementary isotope and concentration data therefore suggest differences in the transition state geometry and/or reaction intermediates in each reductant system. AU - Elsner, M. AU - Cwiertny, D.M.* AU - Roberts, L.* AU - Sherwood Lollar, B.* C1 - 1181 C2 - 24430 SP - 4111-4117 TI - 1,1,2,2-Tetrachloroethane Reactions with OH-, Cr(II), Granular Iron, and a Copper-Iron Bimetal: Insights from Product Formation and Associated Carbon Isotope Fractionation. JO - Environ. Sci. Technol. VL - 41 IS - 11 PB - ACS Publ. PY - 2007 SN - 0013-936X ER - TY - JOUR AB - Methyl group oxidation, SN2-type hydrolysis, and SN1-type hydrolysis are suggested as natural transformation mechanisms of MTBE. This study reports for the first time MTBE isotopic fractionation during acid hydrolysis and for oxidation by permanganate. In acid hydrolysis, MTBE isotopic enrichment factors were C = -4.9” ± 0.6” for carbon and H = -55” ± 7” for hydrogen. Position-specific values were C,reactive position = -24.3” ± 2.3” and H,reactive position = -73” ± 9”, giving kinetic isotope effects KIEC = 1.025 ± 0.003 and KIEH = 1.08 ± 0.01 consistent with an SN1-type hydrolysis involving the tert-butyl group. The characteristic slope of 2Hbulk/13Cbulk bulk,H/ bulk,C = 11.1 ± 1.3 suggests it may identify SN1-type hydrolysis also in settings where the pathway is not well constrained. Oxidation by permanganate was found to involve specifically the methyl group of MTBE, similar to aerobic biodegradation. Large hydrogen enrichment factors of H = -109” ± 9” and H,reactive position = -342” ± 16” indicate both large primary and large secondary hydrogen isotope effects. Significantly smaller values reported previously for aerobic biodegradation suggest that intrinsic fractionation is often masked by additional non-fractionating steps. For conservative estimates of biodegradation at field sites, the largest values reported should, therefore, be used. AU - Elsner, M. AU - McKelvie, J.* AU - Lacrampe Couloume, G.* AU - Sherwood Lollar, S.* C1 - 5860 C2 - 24540 SP - 5693-5700 TI - Insight into Methyl tert-Butyl Ether (MTBE) Stable Isotope Fractionation from Abiotic Reference Experiments. JO - Environ. Sci. Technol. VL - 41 IS - 16 PB - ACS Publ. PY - 2007 SN - 0013-936X ER - TY - JOUR AB - The chemical composition of ambient aerosol particles affects numerous important aerosol parameters such as their hygroscopicity, optics, and mass as well as their potentially adverse health effects. The objective of this study was to derive both detailed chemical speciation and useful proxies for the quantitative classification of the organic matter (OM) content of carbonaceous aerosol samples. Using three different thermal desorption techniques in an inert atmosphere we investigated eight different carbonaceous particulate matter (PM) samples used for health effect studies: thermal desorption gas chromatography with mass spectrometry, evolved gas analysis with mass spectrometry, and thermogravimetry with Fourier transform infrared spectroscopy. The samples include different types of laboratory-generated particles (pigment black, diffusion flame soot, spark-generated carbon) and two ambient aerosol samples (diesel soot and particulates collected in a road tunnel). All samples showed increasing mass desorption with rising temperature, but no reliable OM classification was possible based on thermal mass desorption alone. In fact, the “organic-free” spark-generated carbon particles showed the second highest mass desorption at 800 °C due to the formation of oxygenated structures on unsaturated surface sites and the subsequent evolution of CO and CO2 at elevated temperatures. A quantitative OM classification was accomplished by combining measurements of thermogravimetry and mass spectrometry (up to 800 °C) into a novel parameter, the “apparent organic mass fraction”. The validity of this classification was confirmed with a second proxy parameter, based only on the evolution of organic components during thermal desorption and information on the generation process of the particles. Both types of pigment blacks (Printex) samples and the spark-generated carbon particles showed the lowest apparent organic mass fraction (<5%), whereas for road tunnel and diesel emission particles <16 and <19% was estimated, respectively. AU - Matuschek, G. AU - Karg, E.W. AU - Schröppel, A. AU - Schulz, S. AU - Schmid, O. C1 - 1821 C2 - 24972 SP - 8406-8411 TI - Chemical investigation of eight different types of carbonaceous particles using thermoanalytical techniques. JO - Environ. Sci. Technol. VL - 41 IS - 24 PB - ACS Publ. PY - 2007 SN - 0013-936X ER - TY - JOUR AB - Concentrations of ambient semivolatile organic compounds (SVOC) in the PM2.5 fraction of Augsburg, Germany, have been monitored on a daily basis from January 2003 through December 2004. Samples were taken in a large garden in the city center. Quantitative analysis of n-alkanes, alkanones, alkanoic acid methylesters, long chain linear alkyl benzenes and toluenes, hopanes, polycyclic aromatic hydrocarbons (PAH) and oxidized PAH, and some abietan type diterpenes was done. All compounds showed distinct seasonal variations in concentration. Most compounds showed highest concentrations during the cold seasons, but some n-alkanones and 6,10,14-trimethylpentadecanone showed maximum concentration during summer. Changes in patterns between and within compound classes were obvious, e.g., the hopane pattern exhibited a strong seasonal variation. The main source related contributions to changes observed were discussed. Using positive matrix factorization (PMF) for the statistical investigation of the data set, five factors have been separated. These factors are dominated by the pattern of single sources or groups of similar sources: factor 1, lubricating oil; factor 2, emissions of unburned diesel and heating oil consumption; factor 3, wood combustion; factor 4, brown coal combustion; and factor 5, biogenic emissions and transport components. Like the SVOC, the factors showed strong seasonality with highest values in winter for factors 1-4 and in summer for factor 5. AU - Schnelle-Kreis, J.* AU - Sklorz, M. AU - Orasche, J.* AU - Stölzel, M.* AU - Peters, A. AU - Zimmermann, R. C1 - 2684 C2 - 24558 SP - 3821-3828 TI - Semi volatile organic compounds in ambient PM2.5. Seasonal trends and daily resolved source contributions. JO - Environ. Sci. Technol. VL - 41 IS - 11 PB - ACS Publ. PY - 2007 SN - 0013-936X ER - TY - JOUR AU - Einsiedl, F. AU - Mayer, B.* C1 - 4465 C2 - 24007 SP - 6697-6702 TI - Hydrodynamic and microbial processes controlling nitrate in a fissured-porous karst aquifer of the Franconian Alb, Southern Germany. JO - Environ. Sci. Technol. VL - 40 PY - 2006 SN - 0013-936X ER - TY - JOUR AB - Different particulate matter (PM) samples were investigated by on-line single-particle aerosol time-of-flight mass spectrometry (ATOFMS). The samples consist of soot particulates made by a diffusion flame soot generator (combustion aerosol standard, CAST), industrially produced soot material (printex), soot from a diesel passenger car as well as ambient particulates (urban dust (NIST) and road tunnel dust). Five different CAST soot particle samples were generated with different elemental carbon (EC) and organic carbon (OC) content. The samples were reaerosolized and on-line analyzed by ATOFMS, as well as precipitated on quartz filters for conventional EC/OC analysis. For each sample ca. 1000 ATOFMS single-particle mass spectra were recorded and averaged. A typical averaged soot ATOFMS mass spectrum shows characteristic carbon cluster peak progressions (Cn+) as well as hydrogen-poor carbon cluster peaks (CnH(1-3)+). These peaks are originated predominately from the elemental carbon (EC) content of the particles. Often additional peaks, which are not due to carbon clusters, are observed, which either are originated from organic compounds (OC-organic carbon), or from the non-carbonaceous inorganic content of the particles. By classification of the mass spectral peaks as elemental carbon (i.e., the carbon cluster progression peaks) or as peaks originated from organic compounds (i.e., molecular and fragment ions), the relative abundance of elemental (EC) and organic carbon (OC) can be determined. The dimensionless TC/EC values, i.e., the ratio of total carbon content (TC, TC = OC + EC) to elemental carbon (EC), were derived from the ATOFMS single-particle aerosol mass spectrometry data. The EC/TC values measured by ATOFMS were compared with the TC/EC values determined by the thermal standard techniques (thermooptical and thermocoulometric method). A good agreement between the EC/TC values obtained by on-line ATOFMS and the offline standard method was found. AU - Ferge, T. AU - Karg, E.W. AU - Schröppel, A. AU - Coffee, K.R.* AU - Tobias, H.J.* AU - Frank, M.* AU - Gard, E.E.* AU - Zimmermann, R. C1 - 2689 C2 - 24950 SP - 3327-3335 TI - Fast determination of the relative elemental and organic carbon content of aerosol samples by on-line single-particle aerosol time-of-flight mass spectrometry. JO - Environ. Sci. Technol. VL - 40 IS - 10 PB - ACS Publ. PY - 2006 SN - 0013-936X ER - TY - JOUR AU - Fischer, A.* AU - Bauer, J.* AU - Meckenstock, R.U. AU - Stichler, W. AU - Griebler, C. AU - Maloszewski, P. AU - Kästner, M.* AU - Richnow, H.H.* C1 - 2803 C2 - 23645 SP - 4245-4252 TI - A multitracer test proving the reliability of rayleigh equation-based approach for assessing biodegradation in a BTEX contaminated aquifer. JO - Environ. Sci. Technol. VL - 40 PY - 2006 SN - 0013-936X ER - TY - JOUR AU - Mancini, S.A.* AU - Hirschorn, S.K.* AU - Elsner, M. AU - Lacrampe-Couloume, G.* AU - Sleep, B.E.* AU - Edwards, E.A.* AU - Sherwood Lollar, B.* C1 - 5810 C2 - 24136 SP - 7675-7681 TI - Effects of trace element concentration on enzyme controlled stable isotopes fractionation during aerobic biodegradation of toluene. JO - Environ. Sci. Technol. VL - 40 PY - 2006 SN - 0013-936X ER - TY - JOUR AB - Nonstationary combustion conditions at municipal solid waste incineration (MSWI) plants cause increased crude gas concentrations of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and other products of incomplete combustion (PIC). Such transient conditions occur, e.g., during and after start-up processes in MSWI plants. The start-up and shut-down processes of a MSWI plant were investigated in detail. PCDD/F and other PIC concentrations were determined in the crude gas, in the boiler ash, and in the ash from the electrostatic precipitator (ESP ash), with the outcome that only the start-up procedure significantly affected the concentrations of the organic pollutants in the flue gas and in the ESP ash. The shut-down procedure was evaluated as less problematic for the concentration of the organic pollutants. Moreover the concentration of the PCDD/F and other PIC in the boiler ash was determined as not influenced by shut-down and start-up processes. The homologue profiles and the congener patterns as well as the PCDF/PCDD ratio in the flue gas and in the ESP ash change during MSWI start-up. The changing patterns point at a transition from dominant de novo synthesis to precursor synthesis. AU - Neuer-Etscheidt, K. AU - Nordsieck, H.O.* AU - Liu, Y.* AU - Kettrup, A. AU - Zimmermann, R. C1 - 4471 C2 - 23535 SP - 342-349 TI - PCDD/F and other micropollutants in MSWI crude gas and ashes during plant start-up and shut-down processes. JO - Environ. Sci. Technol. VL - 40 IS - 1 PY - 2006 SN - 0013-936X ER - TY - JOUR AU - Reithmeier, H.* AU - Lazarev, V.* AU - Rühm, W. AU - Schwikowski, M.* AU - Gäggeler, H.W.* AU - Nolte, E.* C1 - 5771 C2 - 24161 SP - 5891-5896 TI - Estimate of European 129I releases supported by 129I analysis in an alpine ice core. JO - Environ. Sci. Technol. VL - 40 PY - 2006 SN - 0013-936X ER - TY - JOUR AU - Safinowski, M.* AU - Griebler, C. AU - Meckenstock, R.U. C1 - 3055 C2 - 23644 SP - 4165-4173 TI - Anaerobic cometabolic transformation of polycyclic and heterocyclic aromatic hydrocarbons: Evidence from laboratory and field studies. JO - Environ. Sci. Technol. VL - 40 PY - 2006 SN - 0013-936X ER - TY - JOUR AU - Schroll, R. AU - Becher, H.H.* AU - Dörfler, U. AU - Gayler, S. AU - Grundmann, S. AU - Hartmann, H.P. AU - Ruoss, J. C1 - 4802 C2 - 23563 SP - 3305-3312 TI - Quantifying the effect of soil moisture on the aerobic microbial mineralization of selected pesticides in different soils. JO - Environ. Sci. Technol. VL - 40 PY - 2006 SN - 0013-936X ER - TY - JOUR AU - Amme, M.* AU - Bors, W. AU - Michel, C. AU - Stettmaier, K. AU - Rasmussen, G.* AU - Betti, M.* C1 - 3354 C2 - 22656 SP - 221-229 TI - Effects of Fe(II) and hydrogen peroxide interaction upon dissolving UO2 under geologic repository conditions. JO - Environ. Sci. Technol. VL - 39 PY - 2005 SN - 0013-936X ER - TY - JOUR AB - Chemical and isotope analyses on groundwater sulfate and 3H measurements on groundwater were used to determine the sulfate sources and sulfur transformation processes in a heterogeneous karst aquifer of the Franconian Alb, southern Germany. Sulfate was found to be derived from atmospheric deposition. Young groundwater was characterized by high sulfate concentrations and δ34S values similar to those of recent atmospheric sulfate deposition. However, the δ18O values of groundwater SO42- were depleted by several per mil with respect to those of atmospheric deposition. This isotopic shift is indicative of mineralization of carbon-bonded S in the vadose zone of the karst system. In groundwater with mean residence times of more than 60 years, a trend of increasing δ34S values and δ18O values with decreasing sulfate concentrations was observed. This trend could not be solely explained by preindustrial atmospheric sulfate deposition with higher δ34S values, and hence, we conclude that bacterial (dissimilatory) sulfate reduction in the porous matrix of the karst aquifer must have occurred. This process has the potential to contribute to long-term biodegradation of contaminants in the porous rock matrix representing the dominant water reservoir of the fissured porous karst aquifer. AU - Einsiedl, F. AU - Mayer, B.* C1 - 1701 C2 - 22924 SP - 7118-7125 TI - Sources and processes affecting sulfate in a karstic groundwater system of the Franconian Alb, Southern Germany. JO - Environ. Sci. Technol. VL - 39 IS - 18 PY - 2005 SN - 0013-936X ER - TY - JOUR AB - The emission of particulate matter and gaseous compounds during combustion of wood and refuse-derived fuel in a small batch reactor is investigated by laser mass-spectrometric on-line measurement techniques for gas-phase analysis and simultaneous registration of physical aerosol properties (number size distribution). The gas-phase composition is addressed by a laser-based mass spectrometric method, namely, vacuum-UV single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS). Particle-size distributions are measured with a scanning mobility particle sizer. Furthermore, a photoelectric aerosol sensor is applied for detection of particle-bound polycyclic aromatic hydrocarbons. The different phases of wood combustion are distinguishable by both the chemical profiles of gas-phase components (e.g., polycyclic aromatic hydrocarbons, PAH) and the particle-size distribution. Furthermore, short disturbances of the combustion process due to air supply shortages are investigated regarding their effect on particle-size distribution and gas-phase composition, respectively. It is shown that the combustion conditions strongly influence the particle-size distribution as well as on the emission of particle-bound polycyclic aromatic hydrocarbons. AU - Ferge, T. AU - Maguhn, J. AU - Hafner, K. AU - Mühlberger, F. AU - Davidovic, M.* AU - Warnecke, R.* AU - Zimmermann, R. C1 - 4552 C2 - 22593 SP - 1393-1402 TI - On-line analysis of gas-phase composition in the combustion chamber and particle emission characteristics during combustion of wood and waste in a small batch reactor. JO - Environ. Sci. Technol. VL - 39 IS - 6 PY - 2005 SN - 0013-936X ER - TY - JOUR AB - Co-combustion of coal and waste in power plants poses both environmental and economic challenges, especially because of the high polychlorinated dibenzo-p-dioxin and furan (PCDD/F) emissions from solid waste. In this study, we performed a series of experiments focusing on the prevention of PCDD/F formation by the use of various inhibitors added to the fuel before combustion. A mixture of lignite coal, solid waste, and poly(vinyl chloride) (PVC) was thermally treated in a laboratory-scale furnace at 400 °C. Twenty different additives were investigated at a level of 10 wt % of the total fuel during the experiments. We have divided them into four general groups according to their chemical nature:  metal oxides, N-containing compounds, S-containing compounds, and N- and S-containing compounds. The resulting values showed a significant reduction of PCDD/F levels when N- and S-containing compounds were used as additives to the fuel. Principle component analysis (PCA) was used to illustrate the effect of the 20 different inhibitors on the congener patterns emitted. As a result, the most effective inhibitors for PCDD/F formation in flue gases were determined to be (NH4)2SO4 and (NH4)2S2O3; they are inexpensive and nontoxic materials. Both compounds can suppress the formation of toxic compounds such as PCDD/Fs by more than 98−99%, and the most toxic PCDD/F congeners were not detectable in most of the samples. Thus, these compounds were also studied as a lower percentage of the fuel. (NH4)2SO4 resulted in a greater than 90% reduction of PCDD/F even when composing only 3% of the fuel combusted. However, less than 5% (NH4)2S2O3 resulted in far weaker inhibition. The PCDD/F homologue distribution ratio for samples with varying percentages of (NH4)2SO4 and (NH4)2S2O3 was also investigated. Higher percentages of the inhibitors produced a lower percentage of lower chlorinated PCDDs. The opposite effect was found for PCDFs. AU - Pandelova, M. AU - Lenoir, D. AU - Kettrup, A. AU - Schramm, K.-W. C1 - 3111 C2 - 22664 SP - 3345-3350 TI - Primary measures for reduction of pcdd/f in co-combustion of lignite coal and waste: Effect of various inhibitors. JO - Environ. Sci. Technol. VL - 39 IS - 9 PY - 2005 SN - 0013-936X ER - TY - JOUR AB - The primary goal of this work was to develop quinonoid-enriched humic materials with enhanced redox properties that could be used as potentially effective redox mediators and reducing agents for in situ remediation of soil and aquatic environments. Two different strategies were formulated and tested to derive these materials. The first strategy called for the oxidation of phenolic fragments associated with the humic aromatic core. In a second strategy, polycondensation of these phenolic fragments was carried out with hydroquinone and catechol. The oxidized derivatives and copolymers obtained were characterized using elemental and functional group analyses, and capillary zone electrophoresis. The redox properties were evaluated using ESR spectrometry and reducing capacity determinations. The reducing capacities of copolymers ranged between 1 and 4 mmol/g, which were much higher than the parent material and the oxidized derivatives. Hence, preference should be given to the copolycondensation approach. The quinonoid-enriched humics are nontoxic, water soluble, and resistant to biodegradation; thus, they could be applied as soil amendments to reduce highly mobile oxoanions of heavy metals and radionuclides, or as redox mediators to enhance in situ bioremediation. Otherwise, cross-linked copolymers could be created to serve as inexpensive reductants in permeable reactive barriers designed to remove highly oxidized contaminants from polluted groundwaters. AU - Perminova, I.V.* AU - Kovalenko, A.A.* AU - Schmitt-Kopplin, P. AU - Hatfield, K.* AU - Hertkorn, N. AU - Belyaeva, E.Y.* AU - Petrosyan, V.S.* C1 - 5531 C2 - 23372 SP - 8518-8524 TI - Design of quinonoid-enriched humic materials with enhanced rediox properties. JO - Environ. Sci. Technol. VL - 39 IS - 21 PY - 2005 SN - 0013-936X ER - TY - JOUR AB - Atomic force microscopy (AFM) was used to determine the shape of fine and ultrafine ambient aerosol particles with sizes between 25 and 700 nm after soft landing on a solid substrate. The particles were collected in summer during daytime at a relative humidity around 50%. To avoid kinetically induced deformation, as previously observed using high-velocity sampling in impactors, the particles were collected on pore filters at very low face velocities (on the order of 10 cm/s). The shape of the collected particles was quantified in terms of their height and apparent diameter. The amount of broadening introduced by the pyramidal shape of the nonideally sharp AFM tips was calibrated using Latex reference spheres with a range of diameters. The height-to-diameter ratios, H/D, of the collected aerosol particles could be extracted from the measured data. Specified in terms of volume-equivalent (dry) diameters, Dv, the size selected frequency distributions of the H/Dv-ratios were found to be bimodal. A small mode centered at H/Dv = 1.0 +/- 0.1 is attributed to nonhygroscopic particles that retained their shape after deposition on the substrate. The large mode, with a peak at H/Dv = 0.65 +/- 0.05, reflects soft particles which were strongly deformed due to vertical collapse after deposition. The pronounced deformation suggests that these particles had previously experienced deliquescence and, when collected at a comparatively low humidity, were in a metastable, supersaturated aqueous state. After landing and indoor sample storage the water evaporated, resulting in minimum H/Dv-ratios as low as 0.45. The dried metastable fraction amounted to 81 +/- 12% in the size range 150 < Dv < 700 nm, and 79 +/- 10% for 50 < or = Dv < or = 150 nm, but only 26 +/- 10% for Dv < 50 nm. Comparison with recently reported data suggests that the observed metastable fraction is the same as the hygroscopic fraction identified by other means. The interpretation is further substantiated by a comparison of the size distributions of collected and airborne particles. AU - Wittmaack, K. AU - Strigl, M.* C1 - 5281 C2 - 23299 SP - 8177-8184 TI - Novel approach to identifying supersaturated metastable ambient aerosol particles. JO - Environ. Sci. Technol. VL - 39 IS - 21 PY - 2005 SN - 0013-936X ER - TY - JOUR AB - In several recent studies it was shown that high atmospheric loads of submicrometer particles in the size range below 500 nm have strong impact on human health. Therefore, extensive research concerning the reduction of fine particle emissions is needed to further improve air quality. Regarding health effects, especially the emission characteristics of fine and ultrafine particles emerging from anthropogenic sources such as combustion processes are of special interest. This study shows that the emission characteristic of an electrostatic precipitator (ESP) due to re-entrainment of fine particles and their subsequent release into the atmosphere can be significantly lowered by application of different operating conditions. For this purpose the particle collection efficiency of an ESP was studied in a municipal sewage sludge incineration plant. Particles were sampled under different operating conditions upstream and downstream from the ESP, and the particle number concentrations were measured simultaneously with aerodynamic particle sizers. In addition, the size distribution of the particles downstream from the ESP was measured with high time resolution by an electrical low-pressure impactor to investigate the particle re-entrainment into the flue gas. To determine the influence of operating conditions, different rapping cycles were investigated regarding their impact on the collection efficiency and the subsequent particle re-entrainment. AU - Ferge, Th. AU - Maguhn, J. AU - Felber, H.* AU - Zimmermann, R. C1 - 2033 C2 - 21710 SP - 1545-1553 TI - Particle Collection Efficiency and Particle Re-entrainment of an Electrostatic Precipitator in a Sewage Sludge Incineration Plant. JO - Environ. Sci. Technol. VL - 38 IS - 5 PY - 2004 SN - 0013-936X ER - TY - JOUR AB - To evaluate the intrinsic bioremediation potential in an anoxic tar oil-contaminated aquifer at a former gasworks site, groundwater samples were qualitatively and quantitatively analyzed by compound-specific isotope analysis (CSIA) and signature metabolites analysis (SMA). C-13/C-12 fractionation data revealed conclusive evidence for in situ biodegradation of benzene, toluene, o-xylene, m/p-xylene, naphthalene, and 1-methylnaphthalene. In laboratory growth studies, C-13/C-12 isotope enrichment factors for anaerobic degradation of naphthalene (epsilon = -1.1 +/- 0.4) and 2-methylnaphthalene (epsilon = -0.9 +/- 0.1) were determined with the sulfate-reducing enrichment culture N47, which was isolated from the investigated test site. On the basis of these and other laboratory-derived enrichment factors from the literature, in situ biodegradation could be quantified for toluene, o-xylene, m/p-xylene, and naphthalene. Stable carbon isotope fractionation in the field was also observed for ethylbenzene, 2-methylnaphthalene, and benzothiophene but without providing conclusive results. Further evidence for the in situ turnover of individual BTEX compounds was provided by the presence of acetophenone, o-toluic acid, and p-toluic acid, three intermediates in the anaerobic degradation of ethylbenzene, o-xylene, and p-xylene, respectively. A number of groundwater samples also contained naphthyl-2-methylsuccinic acid, a metabolite that is highly specific for the anaerobic degradation of 2-methylnaphthalene. Additional metabolites that provided evidence on the anaerobic in situ degradation of naphthalenes were 1-naphthoic acid, 2-naphthoic acid, 1,2,3,4-tetrahydronaphthoic acid, and 5,6,7,8-tetrahydronaphthoic acid. 2-Carboxybenzothiophene, 5-carboxybenzothiophene, a putative further carboxybenzothiophene isomer, and the reduced derivative dihydrocarboxybenzothiophene indicated the anaerobic conversion of the heterocyclic aromatic hydrocarbon benzothiophene. The combined application of CSIA and SMA, as two reliable and independent tools to collect direct evidence on intrinsic bioremediation, leads to a substantially improved evaluation of natural attenuation in situ. AU - Griebler, C. AU - Safinowski, M.* AU - Vieth, A.* AU - Richnow, H.H.* AU - Meckenstock, R.U. C1 - 4950 C2 - 21723 SP - 617-631 TI - Combined application of stable carbon isotope analysis and specific metabolites determination for assessing in situ degradation of aromatic hydrocarbons in a Tar oil-contaminated aquifer. JO - Environ. Sci. Technol. VL - 38 IS - 2 PY - 2004 SN - 0013-936X ER - TY - JOUR AB - A test system has been developed that allows the formation of mass balances for 14C-labeled organic compounds in soil-plant-atmosphere systems under field conditions. The main focus was the quantification of all different 14C-labeled gaseous losses from soil and plant surfaces after the application of 14C-labeled chemicals; therefore, a two-chamber system with specially designed trapping facilities was designed. Volatile 14C-labeled compounds and 14CO2 resulting from the total degradation of the applied 14C-labeled chemical could be trapped separately, and 14C gaseous losses from plant and soil surfaces could be determined separately as well. With this test system, it was feasible for the first time to distinguish between 14C volatile and 14CO2 losses from soil surfaces and from plant surfaces in soil monolith systems under real environmental conditions. The system itself was established on surfaces of soil monoliths (lysimeters) to study the above-mentioned processes along with the transport and leaching behavior of the chemicals in soil cores. With the new system, the behavior of organic chemicals was followed up for a whole vegetation period, and a mass balance for the applied chemical was established. Therefore, a better prediction of the long-term behavior of organic chemicals under real environmental climatic conditions was achieved. The first results for the fate of the model herbicide isoproturon in two different types of agricultural soils are presented and compared with results from an extensive laboratory study. AU - Schroll, R. AU - Kühn, S.S. C1 - 2066 C2 - 21699 SP - 1537-1544 TI - Test system to establish mass balances for 14C-labeled substances in soil, plant, atmosphere systems under field conditions. JO - Environ. Sci. Technol. VL - 38 IS - 5 PB - ACS Publ. PY - 2004 SN - 0013-936X ER - TY - JOUR AB - Trichloroacetic acid (TCA) has been implicated as an airborne pollutant responsible for adverse effects on forest health. There is considerable debate as to whether TCA observed in trees and forest soils is derived from atmospheric deposition or from in situ production. This experiment reports the results from treating 4-year-old Sitka spruce (Picea sitchensis (Bong.) Carr) plants in a greenhouse over a growing season with TCA supplied either to the soil or to the foliage at concentrations of 10 and 100 ng mL-1. Similar uptake of TCA by needles was observed for both modes of treatment, with significant accumulation of TCA (300 ng g-1 dry wt) at the higher concentration. Larger concentrations in stem tissue were seen for the foliar-applied TCA (280 ng g-1) than for the soil-applied TCA (70 ng g-1), suggesting that direct stem uptake may be important. Six months after treatments stopped, TCA concentrations in the needles of plants exposed to 100 ng mL-1 TCA were still enhanced, showing that biological degradation of TCA in needles was slow over the winter. By contrast, no significant enhancement of TCA in soil could be detected in the directly treated soils even during the experiment. The protein content of needles treated with the higher concentration of TCA by either route was significantly smaller than for the controls, but there was no effect of TCA on the conjugation of 1-chloro-2,4-dinitrobenzene in roots nor on the conjugation of 1,2-dichloro-4-nitrobenzene in needles. AU - Cape, J.N.* AU - Reeves, N.M.* AU - Schröder, P. AU - Heal, M.R.* C1 - 10196 C2 - 21441 SP - 2953-2957 TI - Long-term exposure of sitka spruce seedlings to trichloroacetic acid. JO - Environ. Sci. Technol. VL - 37 IS - 13 PY - 2003 SN - 0013-936X ER - TY - JOUR AB - The size distribution of particles in the waste gas of a municipal waste incineration plant (23 MW) was measured on-line at two sampling points in the flue-gas duct (700 and 300 °C) as well as in the stack gas (80 °C). The measurements were performed during both stable combustion conditions and transient operating conditions. The particle measurements were carried out by a mobile system consisting of a home-designed sampling system with dilution device and a scanning mobility particle sizer (SMPS) for the particle size range 17−600 nm as well as an aerodynamic particle sizer (APS) for the size range 500 nm−30 μm. The APS and SMPS data were combined using a special method and a home written software tool. The maximum of the particle-size distribution in the flue gas of the incinerator shifts from about 90 nm at the 700 °C sampling point to about 140 nm at the 300 °C point, showing the particle growth by coagulation processes and condensation of inorganic and organic gaseous species with decreasing temperature. This finding is consistent with the measured concentration profiles of gaseous organic chemical species in the flue gas. While at flue-gas temperatures of 600−800 °C a rich pattern of polycyclic aromatic hydrocarbon species (PAH) is observable, the PAH concentrations are considerably reduced further downstream of the flue-gas channel, where the temperature drops below 500 °C. Condensation and reactive bonding of gaseous chemicals onto particulate matter is, among other reasons, responsible for the depletion of gas-phase species. Process control measures, such as firing the back-up burners or cleaning of the grate with pressurized air, can cause dynamic changes of the particle-size distribution. Furthermore the flue-gas cleaning measures have great impact onto both the particle concentration and the size distribution. For this reason the impact of one particular emission reduction device, the wet electrostatic dust precipitator (wet-ESP), is evaluated. The wet-ESP reduces considerably the particle concentration over the whole size range. Behind the flue-gas processing units a broad maximum in the particle-size distribution occurs at about 70 nm, but no pronounced particle-size distribution could be observed. The particle concentration level at this maximum is about 3 magnitudes lower than in the raw flue gas. However, intermittent periods lasting for several minutes of high emissions of ultrafine particles with d < 40 nm were observed. These particles are most likely formed by nucleation processes behind the wet-ESP from gas-phase constituents of the stack gas. AU - Maguhn, J. AU - Karg, E.W. AU - Kettrup, A. AU - Zimmermann, R. C1 - 10195 C2 - 21354 SP - 4761-4770 TI - On-line Analysis of the Size Distribution of Fine and Ultrafine Aerosol Particles in Flue and Stack Gas of a Municipal Waste Incineration Plant : Effects of Dynamic Process Control Measures and Emission Reduction Devices. JO - Environ. Sci. Technol. VL - 37 IS - 20 PY - 2003 SN - 0013-936X ER - TY - JOUR AB - The day to day and diurnal variation of apparent particle density was studied using highly time-resolved measurements of particle number distribution and fine-particle mass concentration. The study was conducted in Erfurt, Germany, from January 1, 1999, to November 22, 2000. A setup consisting of a differential mobility particle spectrometer and a laser aerosol spectrometer was used for particle number distribution measurements. PM2.5 particle mass was measured in parallel on an hourly basis using a tapered element oscillating microbalance (TEOM) and on daily base by using a Harvard marple impactor (HI). For the estimation of the mean apparent density of particles, number size distributions were converted into volume size distributions, assuming that the particles were spherically shaped. The volume size distributions were integrated over the range of 10 nm to 2.03 μm Stokes equivalent diameter to obtain volume concentrations. Mean apparent particle density was calculated as ratio of mass concentration and volume concentration. The mean apparent particle density, determined from HI and number size distribution on a daily basis was 1.6 ± 0.5 g cm-3. We found a strong day-to-day variation of apparent density ranging from 1.0 to 2.5 g cm-3 (5th and 95th percentile). Furthermore, the apparent density showed pronounced diurnal pattern both in summer and in winter and also on weekdays and weekends. The apparent density was lowest in the morning and highest in the afternoon. The mean apparent density on an hourly basis was 1.4 ± 0.5 and 1.5 ± 0.5 g cm-3 for PM2.5TEOM and corrected PM2.5TEOM using regression equation between daily mass concentration of HI and TEOM, respectively. The strong diurnal variation of apparent particle density was associated predominantly with the vertical temperature inversion and with traffic intensity. Thus, the apparent particle density depends on the physical particle properties and might be related to chemical composition of the sampled particle. AU - Pitz, M. AU - Cyrys, J. AU - Karg, E.W. AU - Wiedensohler, A.* AU - Wichmann, H.-E. AU - Heinrich, J. C1 - 10194 C2 - 21351 SP - 4336-4342 TI - Variability of Apparent Particle Density of an Urban Aerosol. JO - Environ. Sci. Technol. VL - 37 IS - 19 PY - 2003 SN - 0013-936X ER - TY - JOUR AB - Aquatic humic substances (HS) from a bog lake water, a river water, and a groundwater were isolated after enrichment on XAD 8 columns and added to a Czapek-Dox nutrient broth which was used either in full strength or without glucose and/or NaNO3. The individual flasks were inoculated with natural microbial populations of corresponding water samples or with a Pseudomonas fluorescens strain isolated from groundwater. The presence of HS resulted in an increase of bacterial numbers in nearly all cultures incubated for 3 weeks at 25 °C on a shaker. HS reisolated from cultures without glucose or NaNO3 showed no or only minor quantitative differences as compared to those from sterile controls. In full strength nutrient broth up to 27% of HS were utilized. Data obtained by spectroscopic methods (UV/vis/FTIR) and elemental analysis indicated a decrease in particle size and a loss in aromaticity and aliphatic carbon in HS reisolated from the microbial cultures. Simultaneously an increase in the N content of HS was observed, which probably originated from some constituents of microbial biomass such as proteins and amino sugars. The NMR data also documented that significant transformations of HS occurred in the individual microbial cultures. After incubation, increased amounts of aromatic acids were detected in some liquid media and residual HS by GC/MS or capillary electrophoresis. 1H NMR spectroscopy was less effective in indicating structural differences in the HS than 13C NMR but revealed considerable detail of the microbial degradation of riverine HS, when limited sample was available. The newly developed NMR increment analysis provided substantial detail of aromatic structures in a microbially altered HS. The microbial degradation of HS strongly depended on the composition of the HS, the species selection of the microorganisms, and to a lesser extent on the culture conditions. For any series of identical inoculum and HS, full broth media initiated the most extensive alteration of HS. AU - Hertkorn, N. AU - Claus, H.* AU - Schmitt-Kopplin, P. AU - Perdue, E.M.* AU - Filip, Z.K.* C1 - 33104 C2 - 20395 SP - 4334-4345 TI - Utilization and transformation of aquatic humic substances by autochthonous microorganisms. JO - Environ. Sci. Technol. VL - 36 IS - 20 PB - ACS Publications PY - 2002 SN - 0013-936X ER - TY - JOUR AU - Zsolnay, A. C1 - 21982 C2 - 20510 SP - 4195 TI - Comment on "Fluorescence Inner-Filtering Correction for Determining the Humification Index of Dissolved Organic Matter". JO - Environ. Sci. Technol. VL - 36 IS - 19 PY - 2002 SN - 0013-936X ER - TY - JOUR AB - The profiles of different products of incomplete combustion (PIC) in the flue gas of a 1 MW pilot combustion facility were investigated under normal steady-state and disturbed combustion conditions. The behavior of emission profiles after disturbed combustion conditions was investigated in order to obtain a better understanding of emission memory effects. Highly time-resolved, quantitative on-line measurements of several aromatic species down to low ppbv or higher pptv concentrations were performed by a mobile resonance-enhanced multiphoton ionization time-of-flight mass spectrometer. Conventional analytical methods (gas chromatography-mass spectrometry and high-performance liquid chromatography) were also applied for measurement of polycyclic aromatic hydrocarbons (PAH) and polychlorinated dibenzo-p-dioxins and -furans (PCDD/F). The sampling point was located in the high-temperature region of the plant at the outlet of the post-combustion chamber at temperatures between 650 and 880 degrees C, prior to any emission reduction devices. The investigation pointed out that after a short phase of disturbed combustion conditions, e.g., due to process changes, transient puffs, or malfunctions, the composition of combustion byproducts in the flue gas can be changed drastically for a very long time (memory emission" effect). It is suggested that carbonaceous layers, deposited on the inner walls in the high-temperature zone of the plant, might be responsible for the observed memory emission of some PAH species. Drastic changes in the profiles of the PCDD/F homologues were also observed during memory emission conditions. The PAH memory most likely is due to pyrolytic degradation of the carbonaceous layers, while the altered PCDD/F homologue pattern may be mediated by the high catalytic activity of the freshly formed deposit layers. Finally, it should be emphasized that a rich pattern of aromatic species, including PCDD/F, was found in a temperature regime well above the typical temperature window (approximately 300 degrees C) for de novo PCDD/F formation." AU - Zimmermann, R. AU - Blumenstock, M. AU - Heger, H.- J. AU - Schramm, K.-W. AU - Kettrup, A. C1 - 10193 C2 - 19751 SP - 1019-1030 TI - Emission of Nonchlorinated and Chlorinated Aromatics in the Flue Gas of Incineration Plants during and after Transient Disturbances of Combustion Conditions: Delayed Emission Effects. JO - Environ. Sci. Technol. VL - 35 IS - 6 PB - American Chemical Society PY - 2001 SN - 0013-936X ER - TY - JOUR AB - It has been assessed the influence of four organic amendments (OA) consisting of two commercial humic amendments (liquid LF and solid SF) from olive-mill wastes, a solid urban waste (SUW), and a sewage sludge (SS) on the sorption properties and leaching potential of simazine and 2,4-D. A sandy soil (TR) and a sandy-clay soil with a relatively high montmorillonite content (A) were treated with the diverse OA. Dissolved organic matter (DOM) was extracted from the amendments, the soils, and the amended soils and studied by fluorescence spectroscopy. A humification index (HIX) was calculated from the fluorescence data. Sorption was determined with the batch technique. Spectroscopical studies revealed that the DOM of the LF differs from the other OA by having a very low ability to absorb and to fluoresce and by its very low HIX values, which indicates that the LF contains large amounts of nonhumified material and consists of small molecules. On the other hand, the SF amendment contains the highest amounts of highly humified material and a large number of carboxylic groups. Amended soils sorbed simazine and 2,4-D to a greater extent than the untreated soils, except in the case of simazine sorption in the LF amended soil A, which had a lower simazine sorption than the original soil. The small molecules of DOM in the LF compete with simazine for montmorillonite sorption sites in soil A. This is not the case for 2,4-D, since this herbicide does not sorb on montmorillonite. In the case of the soil TR, with a lower montmorillonite content, there is no competition between simazine and the LF molecules for sorption sites. Soils amended with the highly humified SF were the best sorbents for simazine but not for 2,4-D, which can be attributed to repulsion between negatively charged 2,4-D molecules and COO- groups, which are more abundant in SF. AU - Cox, L.* AU - Celis, R.* AU - Hermosin, M.C.* AU - Cornejo, J.* AU - Zsolnay, A. AU - Zeller, K. C1 - 24297 C2 - 32743 SP - 4600-4605 TI - Effect of organic amendments on herbicide sorption as related to the nature of the dissolved organic matter. JO - Environ. Sci. Technol. VL - 34 IS - 21 PB - Amer. Chemical Soc. PY - 2000 SN - 0013-936X ER - TY - JOUR AB - The objectives of this work were to study the addition of sulfur and nitrogen containing compounds to the fuel before the combustion, to examine their capacity for preventing PCDD/F emissions, to investigate their influence on the PCDD/F homologue patterns and to determine the most effective additive concentration used for inhibition. Various sulfur and nitrogen containing solid compounds were mixed with Refuse Derived Fuel (RDF) in proportions of 10% w/w of the fuel, and the mixtures were combusted in a lab-scale reactor at 1000 °C. Analysis and quantification of PCDD/F showed that inorganic sulfur containing compounds significantly affected PCDD/F emissions, resulting in more than 98% reduction of toxic compounds. However, urea presented a lower prevention capacity and resulted in about 28% reduction of PCDD/Fs. High PCDD/F prevention efficiencies, about 96%, were also obtained during the combustion of a mixture containing 1% w/w of amidosulfonic acid (ASA) used as the additive. In addition, the presence of sulfur and nitrogen containing compounds affected the PCDD/F formation pathways, as it was observed from the PCDD/F ratios and the homologue profiles. The PCDD/F prevention ability of sulfur containing compounds is discussed; it could be attributed to the formation of sulfur−copper complexes. AU - Samaras, P.* AU - Blumenstock, M. AU - Lenoir, D. AU - Schramm, K.-W. AU - Kettrup, A. C1 - 21596 C2 - 19723 SP - 5092-5096 TI - PCDD/F Prevention by Novel Inhibitors : Addition of Inorganic S- and N-Compounds in the Fuel before Combustions. JO - Environ. Sci. Technol. VL - 34 IS - 24 PY - 2000 SN - 0013-936X ER - TY - JOUR AB - Combustion-related soot particles in the state of formation were sampled from the stoker system of a 0.5 MW incineration pilot plant. The plant was operated with wood as feeding material. Samples were taken in different air supply zones at different heights over the feed bed. Polycyclic aromatic hydrocarbons (PAH) which are adsorbed on the soot particles were analyzed by Fourier transform laser microprobe mass spectrometry (FT LMMS). The structure of the observed PAH patterns was analyzed using a multivariate statistical method (principle component analysis, PCA). The samples obtained closest to the feed bed near the first three air supply zones exhibit the most significant differences in the PAH patterns. This result is due to different contribution of the elementary processes (drying, pyrolysis, gasification, and combustion) in the different zones. Possible applications for monitoring the combustion efficiency of incinerators are discussed. AU - Zimmermann, R. AU - van Vaeck, L.* AU - Davidovic, M.* AU - Beckmann, M.* AU - Adams, F.* C1 - 21434 C2 - 19551 SP - 4780-4788 TI - Analysis of Polycyclic Aromatic Hydrocarbons (PAH) Adsorbed on Soot Particles by Fourier Transform Laser Microprobe Mass Spectrometry (FT LMMS): Variation of the PAH Patterns at Different Positions in the Combustion Chamber of an Incineration Plant. JO - Environ. Sci. Technol. VL - 34 IS - 22 PY - 2000 SN - 0013-936X ER - TY - JOUR AB - Based on the known ability of the white rot fungus Phanerochaete chrysosporium to metabolize PAHs, a fungal reactor system with separate soil extraction and fungal incubation units was constructed. The design of the system allowed samples to be easily removed at strategic positions and to ascertain mineralization. The highly contaminated soil (1-2 mm particle diameter), with a total EPA Method 610 concentration of 41 g of PAHs kg(-1), was spiked with [7,10-C-14]benzo[a]pyrene in order to follow the fate of this tracer by HPLC and high-performance gel permeation chromatography. While mineralization amounted to only 2.5%, it was observed that the fungus reduced the total soil PAH concentration by 45% through polymerization processes. For [7,10-C-14] benzo[a] pyrene, a value of 4.9 mg kg(-1) day(-1) or overall 5.5% was obtained. The polymers remained associated with soil, and no monomeric PAHs were detected in the medium. In parallel experiments without soil, high molecular weight polymers could be found in the medium. Sterile soil and medium controls revealed no polymerization. The results were consistent with literature reports that P. chrysosporium converts PAHs primarily to quinones, which have a strong tendency to polymerize. On the basis of the success of this system, scaling up appears to be justifiable. AU - May, R.* AU - Schröder, P. AU - Sandermann, H. C1 - 23293 C2 - 31177 SP - 2626-2633 TI - Ex-situ process for treating PAH-contaminated soil with Phanerochaete chrysosporium. JO - Environ. Sci. Technol. VL - 31 IS - 9 PB - American Chemical Society PY - 1997 SN - 0013-936X ER - TY - JOUR AB - Model studies were performed to determine quantitatively the predominance of two proposed pathways of polychlorinated dibenzo-p-dioxin (PCDD) formation during municipal refuse incineration: surface-catalyzed reactions of precursors occurring on fly ash and de novo synthesis of PCDD and related compounds from reactions of particulate carbon. The relative yields of PCDD formed from the model precursor compound pentachlorophenol (PCP) were 72-99 000 times higher than PCDD formed from the reactions of activated charcoal, air, inorganic chloride, and Cu(II) as catalyst under identical reaction conditions. Yields and homologue distributions of PCDD were strongly influenced by heating time, air flow rate, and temperature, with marked differences observed between the two pathways. Activated charcoal also catalyzed the formation of PCDD from PCP in the absence of Cu(II) and promoted the dechlorination of PCDD. We speculate that Cu(II) and carbon represent two different types of active catalytic species which could be present on the surface of municipal incinerator fly ash. AU - Dickson, L.C. AU - Lenoir, D. AU - Hutzinger, O. C1 - 40589 C2 - 38764 SP - 1822-1828 TI - Quantitative comparison of de novo and precursor formation of polychlorinated dibenzo-p-dioxins under simulated municipal solid waste incinerator postcombustion conditions. JO - Environ. Sci. Technol. VL - 26 IS - 9 PY - 1992 SN - 0013-936X ER - TY - JOUR AU - Lippert, T. AU - Wokaun, A. AU - Lenoir, D. C1 - 19605 C2 - 12715 SP - 1485-1489 TI - Surface Reactions of Brominated Arenes as a Model for the Formation of Clorinated Dibenzodioxins and -furans in Incineration: Inhibition by Ethanolamine. JO - Environ. Sci. Technol. VL - 25 IS - 8 PY - 1991 SN - 0013-936X ER - TY - JOUR AB - The aryl coupling reaction of bromobenzene on alumina-supported copper catalysts has been studied as model for dioxin formation. The reaction was monitored in situ by transmittance FTIR spectroscopy. Time-dependent changes in the spectra were recorded during addition of bromobenzene to the carrier gas stream. Both coupling of phenyl intermediates to yield biphenyls and formation of phenol and phenolate were observed. Novel approaches to inhibit the coupling reaction of aryl halides by addition of ethanolamine to the catalyst surface were studied. The resulting inhibition was attributed to site blocking and irreversible deactivation of the copper surface due to imine and nitride formation. AU - Lippert, T.H. AU - Wokaun, A. AU - Lenoir, D. C1 - 40768 C2 - 38672 SP - 1485-1489 TI - Surface reactions of brominated arenes as a model for the formation of chlorinated dibenzodioxins and -furans in incineration: Inhibition by ethanolamine. JO - Environ. Sci. Technol. VL - 25 IS - 8 PY - 1991 SN - 0013-936X ER - TY - JOUR AU - Brunner, S. AU - Hornung, E. AU - Santl, H. AU - Wolff, E. AU - Piringer, O.G. AU - Altschuh, J. AU - Brüggemann, R. C1 - 18236 C2 - 11449 SP - 1751-1754 TI - Henry's Law constants for polychlorinated biphenyls: Experimental determination and structure- property relationships. JO - Environ. Sci. Technol. VL - 24 IS - 11 PY - 1990 SN - 0013-936X ER - TY - JOUR AU - Trapp, S. AU - Matthies, M. AU - Scheunert, I. AU - Topp, E.M. C1 - 18105 C2 - 10952 SP - 1246-1252 TI - Modeling the Bioconcentration of Organic Chemicals in Plants. JO - Environ. Sci. Technol. VL - 24 IS - 8 PY - 1989 SN - 0013-936X ER - TY - JOUR AU - Zsolnay, A. AU - Kotzias, D. AU - Herrmann, M.E. C1 - 17176 C2 - 10280 TI - The prediction of photochemical free radical and singlet oxygen production from the light absorbing properties of aquatic systems. JO - Environ. Sci. Technol. PY - 1988 SN - 0013-936X ER -