TY - JOUR AB - Aerosol dosimetry in respiratory airways is relevant for pulmonary drug delivery and inhalation toxicology. Consequently, computational fluid-particle dynamics (CF-PD) modelling of pulmonary aerosol delivery is an active research field. Additionally, mice are the most commonly used animals in medical research. Technological advances have provided information on whole mice lung morphologies with unprecedented high resolution. Therefore, in this study, we used high-resolution light sheet fluorescent microscopy (LSFM) images of a healthy C57BL/6 mouse lung with a constant air flow rate of 72 ml/min, to extract an anatomical 3-dimensional (3D) geometry of the entire airway tree of the left lung from the primary bronchi to the most distal bronchioles excluding the trachea. The airways were segmented based on an order- and generation-based method. Also, to compare the morphological data and regional deposition, a generation-based investigation including 25 generations was employed in the present model. One-way coupling of CF-PD modeling was applied to model an intubated and mechanically-ventilated mouse. Maximum values of the velocity and vorticity magnitude of 3.2 m/s and 200,000 1/s were reached in the second order, respectively, and maximum pressure and wall shear stress levels were 30 Pa and 3.5 Pa, respectively. Finally, order- and generation-based particle deposition efficiency and dose per lung area were obtained for the particle size range of 1 μm ≤ dp ≤ 10 μm yielding pronounced hotspot deposition patterns mainly near the proximal bifurcations. The results showed a positive correlation between deposition efficiency and particle size due to a size-dependent increase in inertial and gravitational effects. Maximum regional deposition and normalized dose was seen for 10 μm particles in the 1st order of the murine left lung. Smaller peak sizes of deposition efficiency were seen in the third and fourth orders of the mouse left lung due to almost complete loss of the largest particles in lower order airways. It also justifies the close to zero deposition efficiency in the highest orders (fifth to sixth). Both lung morphology as well as total and regional aerosol deposition showed reasonably good agreement with empirical data from the literature. The present CF-PD model with accurate realistic lung morphology, improves our knowledge of airway aerosol deposition hotspots. The obtained modeling method and the qualitative results can be implemented on human airways. AU - Estaji, M.* AU - Nabaei, M.* AU - Yang, L. AU - Schmid, O. AU - Farnoud, A. C1 - 73253 C2 - 56819 TI - Aerosol dosimetry in the whole conducting zone of a murine left-lung using CF-PD and LSFM images. JO - J. Aerosol Sci. VL - 181 PY - 2024 SN - 0021-8502 ER - TY - JOUR AB - This paper, one of several in a special issue of the Journal of Aerosol Science on “Inhaled Aerosol Dosimetry”, covers selected methods for defining the respiratory tract anatomy required as input to inhaled aerosol deposition models, along with some applications and challenges. “Anatomy” refers to the study of biological structures and to the structures themselves. Quantitative anatomical data obtained by morphometric measurements are used in inhaled aerosol deposition dose models. The equations used in modeling calculations define the needed specific quantitative anatomy input, whether the model is deterministic, stochastic, semi-empirical, or computational fluid dynamics based. Replica airway casts are widely used for defining airway morphology, and for making hollow models to validate deposition calculations. The parameters measured on casts, e.g., airway lengths, diameters, branching and gravity angles, alveolar shapes, and generational linkages do not capture some important airway details, such as bifurcation shapes, airway motion, deviations from airway smoothness, and non-uniform airway tube diameters. These details can affect inhaled aerosol fates. Advances in methods for scanning airways in living subjects or in non-dissected excised lungs have overcome many of the problems associated with replica cast morphometry, but limitations remain with respect to providing linked airway regions, capturing airway motion, and resolving fine structural detail. There are also needs for cast measurements and scans that represent additional animal species and normal variations within species and individuals. Other methods for defining airway anatomy, such as serial sectioning of fixed or frozen tissue, planar x-ray imaging, and bolus aerosol inhalation, also provide useful airway anatomical data. Along with advances in aerosol dynamics, the current state of understanding airway anatomy is adequate for modeling many medical and environmental exposure cases. However, it appears that advances in understanding respiratory tract anatomy and physiology have lagged behind advances in the quality of aerosol science used in current inhaled aerosol deposition models, with the exception of dynamic and/or multi-component aerosol systems (e.g., cigarette smoke). Accordingly, for anatomists and aerosol scientists working on inhaled aerosol dose models both challenges and opportunities lie ahead for addressing remaining anatomical issues of concern. AU - Phalen, R.F.* AU - Hoover, M.D.* AU - Oldham, M.J.* AU - Schmid, O. AU - Golshahi, L.* C1 - 61771 C2 - 50427 CY - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, Oxon, England TI - Anatomical considerations for inhaled aerosol deposition modeling: Methods, applications, challenges and opportunities. JO - J. Aerosol Sci. VL - 156 PB - Elsevier Sci Ltd PY - 2021 SN - 0021-8502 ER - TY - JOUR AB - Denuder sampling devices consisting of two multi-channel silicone rubber traps separated by a quartz fibre filter, have been effectively employed for the simultaneous sampling of gas and particle associated semi-volatile organic compounds. Here controlled laboratory experiments were conducted to further elucidate the fundamental operating mechanisms of this portable denuder with respect to particle transmissions. Particle collection efficiency of the quartz fibre filters as well as particle transmission efficiency through the silicone rubber traps using ambient aerosol and aqueous suspensions of monodisperse polystyrene latex (PSL) as test particles (0.3, 0.5 and 0.8 mu m), were evaluated for various scenarios. Particle size and number concentration were measured with a scanning mobility particle sizer. Transmission efficiency of the denuder was determined from the ratio of particle concentration transmitted by the denuder to that of a bypass line. All sizes of PSL particles were collected with high efficiency and reproducibility by the quartz fibre filter ( > 98% with variation coefficients < 16%). Overall transmission efficiencies for all particles > 100 nm ranged from 91% to 100% (variation coefficients of 2-14%). Transmission efficiencies decreased when PDMS tubes were twisted but were not significantly different for traps made by different individuals. Ambient particles, which were studied for the first time, were collected with 88-95% collection efficiency. Losses of smaller particle size fractions in the trap portion of the denuder were likely due to diffusion and electrostatic effects. The high particle collection and transmission efficiencies of all tested particle sizes indicated that these denuders are very effective tools for aerosol measurements. AU - Munyeza, C.F.* AU - Kohlmeier, V. AU - Dragan, G.-C. AU - Karg, E.W. AU - Rohwer, E.R.* AU - Zimmermann, R. AU - Forbes, P.B.C.* C1 - 55588 C2 - 46315 CY - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, Oxon, England SP - 22-31 TI - Characterisation of particle collection and transmission in a polydimethylsiloxane based denuder sampler. JO - J. Aerosol Sci. VL - 130 PB - Elsevier Sci Ltd PY - 2019 SN - 0021-8502 ER - TY - JOUR AB - The authors regret for the following typos: 1) The units for the “nanoparticle surface area dose delivered to the lung” (including the EC 50 doses) should read cm 2 /g-lung, not m 2 /g-lung as stated erroneously in the Abstract, the Conclusion section as well as on p. 141 (5 lines and 12 lines above the Conclusions section).2) In Fig 3c, R 2 = 0.19 (not R 2 = 19).The authors would like to apologise for any inconvenience caused. DOI of original article: 10.1016/j.jaerosci.2015.12.006 AU - Schmid, O. AU - Stöger, T. C1 - 52010 C2 - 43645 CY - Oxford SP - 276 TI - Corrigendum to “Surface area is the biologically most effective dose metric for acute nanoparticle toxicity in the lung” [Journal of Aerosol Science 99 (2016) 133–143](S0021850215301166)(10.1016/j.jaerosci.2015.12.006). JO - J. Aerosol Sci. VL - 113 PB - Elsevier Sci Ltd PY - 2017 SN - 0021-8502 ER - TY - JOUR AB - In vitro toxicity testing of airborne particles usually takes place in multi-well plates, where the cells are exposed to a suspension of particles in cell culture medium. Due to the artefacts caused by particle collection and preparation of suspensions, the air-liquid interface (ALI) exposure is challenging this conventional exposure technique to become the method of choice. The ALI technique allows for direct sampling of an aerosol and exposure of cell cultures to airborne particles. At the same time, it reflects the physiological conditions in the lung to a greater extent. So far, the available ALI systems have mostly been laboratory set-ups of the single components. Here, we present a mobile and complete system providing all process technology required for cell exposure experiments at dynamic aerosol sources. The system is controlled by a human machine interface (HMI) with standard routines for experiments and internal testing to assure reproducibility. It also provides documentation of the exposure experiment regarding process parameters and measured doses. The performance of this system is evaluated using fluorescein-sodium dosimetry, which is also used to determine the factor of dose enhancement by optional electrostatic deposition. The application of the system is shown for two different technical aerosol sources: wood smoke particles emitted by a household log wood stove and emissions from a ship diesel engine. After exposure of lung cells, cytotoxicity and gene regulation on a genome-wide scale were analysed. AU - Mülhopt, S.* AU - Dilger, M.* AU - Diabaté, S.* AU - Schläger, C.* AU - Krebs, T.* AU - Zimmermann, R. AU - Buters, J.T.M. AU - Oeder, S. AU - Wäscher, T.* AU - Weiss, C.* AU - Paur, H.R.* C1 - 48260 C2 - 39982 CY - Oxford SP - 38-55 TI - Toxicity testing of combustion aerosols at the air-liquid interface with a self-contained and easy-to-use exposure system. JO - J. Aerosol Sci. VL - 96 PB - Elsevier Sci Ltd PY - 2016 SN - 0021-8502 ER - TY - JOUR AB - In this study, we present the impact of fuel additives (Fe, Al, and V) on the measured particulate organic matter (OM) fraction formed from the combustion of propane-heated diesel fuel (DF) in a DF Combustion Aerosol STandard (DF-CAST) burner prototype within the range of air-fuel-equivalence ratios (λDF) from 5.4 to 10.4. The OM fraction was measured by using high resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) and unmixed into factor profiles by applying the SoFi program, a source apportionment tool using positive matrix factorization (PMF)/multilinear engine (ME-2) solvers. The separated factors were correlated with the particle light absorption properties at UV (370 nm) and IR (950 nm) wavelengths, NO3-, and NH4+ as well as exhaust gas (CO2, CO, NO, NH3, hydrocarbons (HC), and formaldehyde (HCHO)). Addition of Fe, Al, and V to the DF yielded apparent catalytic processes leading to the formation of nitrogen-containing particulate OM (CHN and CHON families). The separated factors were distinct in terms of their oxidation state, correlation with the measured particulate and gaseous emissions. Similarities in the separated factors based on temporal evolution were observed in DF and DF+additive experiments. This study gives a new insight in the modification of DF combustion particle properties in the presence of fuel additives. AU - Müller, L. AU - Schnelle-Kreis, J. AU - Jakobi, G. AU - Orasche, J.* AU - Jing, L.* AU - Canonaco, F.* AU - Prevot, A.S.H.* AU - Zimmermann, R. C1 - 48920 C2 - 41494 CY - Oxford SP - 61-72 TI - Combustion process apportionment of carbonaceous particulate emission from a diesel fuel burner. JO - J. Aerosol Sci. VL - 100 PB - Elsevier Sci Ltd PY - 2016 SN - 0021-8502 ER - TY - JOUR AB - In this study we provide guidance on the biologically most relevant dose metric for pulmonary toxicity of biopersistent, spherical nanoparticles (NPs). A retrospective analysis of nine in vivo studies on particle-induced, acute pulmonary toxicity in animal models (mouse, rat) was performed encompassing five different types of nanomaterials (polystyrene, titanium dioxide, carbonaceous materials, transition metal oxides (Co, Ni, Zn) and hydrothermally synthesized α-quartz) with a wide range of primary particle diameters (9-535nm) and mass-specific BET surface areas (6-800m2/g). The acute influx of polymorphonuclear neutrophils (PMNs) into the lungs after intratracheal instillation of NPs was chosen as a toxicological endpoint for acute lung inflammation. The allometrically scaled toxicological data were investigated with respect to various dose metrics, namely (primary) particle number, joint length, BET and geometric surface area, volume and mass.Surface area is identified as the biologically most relevant dose metric for spherical NPs explaining about 80% of the observed variability in acute pulmonary toxicity (R 2=0.77). None of the other dose metrics explains more than 50% of the observed variability in pulmonary inflammation. Moreover, using surface area as the dose metric allows identification of material-based toxicity classes independent of particle size. Typical materials without intrinsic toxicity - here referred to as low-solubility, low-toxicity (LSLT) materials - show low surface-specific toxicity with an EC50 dose of 175m2/g-lung (geometric mean; σ g =2.2), where EC50 represents the dose inducing 50% of the maximum effect (here 30% PMN). In contrast, transition metal oxides (here Co, Ni, Zn) - materials known for their intrinsic toxicity - display a 12-fold enhanced surface-specific toxicity compared to LSLT particles (EC50=15m2/g-lung).This analysis implies that surface-related modes of action are driving acute pulmonary toxicity for the types of NPs investigated here. The relevance of other dose metrics such as number and volume is acknowledged in the context of different modes of action, namely shape-induced toxicity (fiber paradigm) and extremely high particle lung burden (overload conditions), respectively. So which dose metric should be monitored by aerosol scientists involved in health related aerosol exposure measurements? The short answer is - all of them (except length), but there is a strong preference towards surface area. AU - Schmid, O. AU - Stöger, T. C1 - 48637 C2 - 41231 CY - Oxford SP - 133-143 TI - Surface area is the biologically most effective dose metric for acute nanoparticle toxicity in the lung. JO - J. Aerosol Sci. VL - 99 PB - Elsevier Sci Ltd PY - 2016 SN - 0021-8502 ER - TY - JOUR AB - Ambient particles (PM2.5) are estimated to be the leading source of environmental burden of disease. Modern populations spend more than 80%, often over 90% of their time indoors, where the exposures to ambient particles are modified by the building and ventilation system. The health risks, however, are routinely evaluated and controlled using only outdoor concentration measurements. The objective of the current work is to integrate a number of previously developed methods for estimation of the particle size distribution changes caused by infiltration of particles from outdoor air. The model is evaluated against population-based measurements conducted in 45 homes in Helsinki, Finland, with 3–5 repeated daily measurements. In comparison with previous sulphur-based estimation of PM2.5 infiltration rate, the aerosol model using 12-channel particle number size distribution from an electrical aerosol spectrometer (EAS) as input, was capable of capturing 85% of variance of indoor PM2.5 originating from outdoors. The estimated residential PM2.5 infiltration factor in Helsinki was 0.55±0.13 (mean±sd), while the corresponding values from the previously used elemental marker method were 0.58±0.15. These results demonstrate the importance of the particle size dependent aerosol processes in forming actual human exposures and doses, especially in showing that the exposures and doses are not equally modified by infiltration. AU - Hänninen, O.* AU - Sorjamaa, R.* AU - Lipponen, P.* AU - Cyrys, J. AU - Lanki, T.* AU - Pekkanen, J.* C1 - 28560 C2 - 33450 SP - 111-122 TI - Aerosol-based modelling of infiltration of ambient PM2.5 and evaluation against population-based measurements in homes in Helsinki, Finland. JO - J. Aerosol Sci. VL - 66 PB - Elsevier Science PY - 2013 SN - 0021-8502 ER - TY - JOUR AB - We studied the transport and deposition of quasi-monodisperse nanoparticles (with mobility diameter d(m) ranging from 1 nm to 52 nm) inside an extrathoracic airway model (which showed all relevant features of a computed tomography based model) by numerical simulation and, for part of the size range (14.5 nm <= d(m) <= 52 nm), by experimental measurement. For each particle size, three physiologically relevant steady inspiratory flow rates (Q=10, 20 and 30 l/min) were considered. The validation of the numerical results consisted of (i) a comparison of numerical flow results to available Particle Image Velocimetry and Large-Eddy Simulation data and (ii) a comparison of numerical particle deposition simulations to new nanoparticle deposition measurements as well as previously published experimental and numerical deposition data. Computations of the laminar-turbulent flow were carried out using an open-source steady-state solver in conjunction with the k-omega SST turbulence model. The particle motion and their subsequent deposition was computed by the so-called Eulerian mass transport model. Quasi-monodisperse carbon nanopartides (14.5 nm <= d(m) <= 52 nm) were generated by spark ignition and their deposition was measured in a cast of the extrathoracic airway model. Both simulations and experiments showed that particle deposition increases with decreasing flow rate and decreasing particle size. A direct comparison between our numerical and all available experimental deposition results in fact showed a good overall agreement in the entire flow and size range. In the particle size range that could be studied experimentally in the same extrathoracic airway model geometry (d(m) >= 14.5 nm), absolute differences were of the order of a few percent, in the face of very low deposition fractions in this nanoparticle size range (with all experimental deposition fractions less than 5%). However, when normalizing to the largest deposition for the smallest flow rate (Q = 10 l/min), the dependency on flow rate was very similar between experiments and simulations. An adjustment of the turbulent Schmidt number (0.9-0.5) led to a slightly 'better agreement with experimental values. Finally, the simulations also showed that within the extrathoracic model, particular deposition patterns appeared that were similar for different particle sizes, however with more marked deposition hot-spots for the smallest particle size. AU - Krause, F.* AU - Wenk, A. AU - Lacor, C.* AU - Kreyling, W.G. AU - Möller, W. AU - Verbanck, S.* C1 - 23755 C2 - 31282 SP - 131-143 TI - Numerical and experimental study on the deposition of nanoparticles in an extrathoracic oral airway model. JO - J. Aerosol Sci. VL - 57 IS - 1 PB - Elsevier Science PY - 2013 SN - 0021-8502 ER - TY - JOUR AB - The introduction of engineered nanostructured materials into a rapidly increasing number of industrial and consumer products will result in enhanced exposure to engineered nanoparticles. Workplace exposure has been identified as the most likely source of uncontrolled inhalation of engineered aerosolized nanoparticles, but release of engineered nanoparticles may occur at any stage of the lifecycle of (consumer) products. The dynamic development of nanomaterials with possibly unknown toxicological effects poses a challenge for the assessment of nanoparticle induced toxicity and safety. In this consensus document from a workshop on in-vitro cell systems for nanoparticle toxicity testing(1) an overview is given of the main issues concerning exposure to airborne nanoparticles, lung physiology, biological mechanisms of (adverse) action, in-vitro cell exposure systems, realistic tissue doses, risk assessment and social aspects of nanotechnology. The workshop participants recognized the large potential of in-vitro cell exposure systems for reliable, high-throughput screening of nanoparticle toxicity. For the investigation of lung toxicity, a strong preference was expressed for air-liquid interface (ALI) cell exposure systems (rather than submerged cell exposure systems) as they more closely resemble in-vivo conditions in the lungs and they allow for unaltered and dosimetrically accurate delivery of aerosolized nanoparticles to the cells. An important aspect, which is frequently overlooked, is the comparison of typically used in-vitro dose levels with realistic in-vivo nanoparticle doses in the lung. If we consider average ambient urban exposure and occupational exposure at 5 mg/m(3) (maximum level allowed by Occupational Safety and Health Administration (OSHA)) as the boundaries of human exposure, the corresponding upper-limit range of nanoparticle flux delivered to the lung tissue is 3 x 10(-5)-5 x 10(-3) mu g/h/cm(2) of lung tissue and 2-300 particles/h/(epithelial) cell. This range can be easily matched and even exceeded by almost all currently available cell exposure systems. The consensus statement includes a set of recommendations for conducting in-vitro cell exposure studies with pulmonary cell systems and identifies urgent needs for future development. As these issues are crucial for the introduction of safe nanomaterials into the marketplace and the living environment, they deserve more attention and more interaction between biologists and aerosol scientists. The members of the workshop believe that further advances in in-vitro cell exposure studies would be greatly facilitated by a more active role of the aerosol scientists. The technical know-how for developing and running ALI in-vitro exposure systems is available in the aerosol community and at the same time biologists/toxicologists are required for proper assessment of the biological impact of nanoparticles. AU - Paur, H.R.* AU - Cassee, F.R.* AU - Teeguarden, J.* AU - Fissan, H.* AU - Diabaté, S.* AU - Aufderheide, M.* AU - Kreyling, W.G. AU - Hänninen, O.* AU - Kasper, G.* AU - Riediker, M.* AU - Rothen-Rutishauser, B.* AU - Schmid, O. C1 - 6822 C2 - 29316 SP - 668-692 TI - In-vitro cell exposure studies for the assessment of nanoparticle toxicity in the lung - a dialog between aerosol science and biology. JO - J. Aerosol Sci. VL - 42 IS - 10 PB - Elsevier PY - 2011 SN - 0021-8502 ER - TY - JOUR AB - Effective densities derived from combined mobility and aerodynamic sizing provide a valuable tool for the characterization of non-spherical particles. Different effective densities have been introduced depending on the primary measurement parameters (mass, mobility and/or aerodynamic size) and the flow regime (transition, free-molecular). Here we explore the relationship between these effective densities, their physical interpretation and their dependence on particle shape, density and various equivalent diameters. We also provide an overview over the wide range of practical implications of the effective density concept with a particular focus on the characterization of particles with irregular or even unknown shape using commercially available instruments such as DMA, SMPS, FMPS, ELPI, APS, TEOM and multi-stage impactors. Finally, we identify new perspectives for particle characterization by extending the effective density concept into the free-molecular regime and by suggesting a triple-instrument approach for on-line determination of both particle density and shape as well as the dynamic shape factor for different flow regimes. AU - Schmid, O. AU - Karg, E.W. AU - Hagen, D.E.* AU - Whitefield, P.D.* AU - Ferron, G.A. C1 - 3824 C2 - 24419 SP - 431-443 TI - On the effective density of non-spherical particles as derived from combined measurements of aerodynamic and mobility equivalent size. JO - J. Aerosol Sci. VL - 38 IS - 4 PB - Elsevier PY - 2007 SN - 0021-8502 ER - TY - JOUR AB - Laboratory experiments were performed to investigate the emission of particulate matter by electric universal motors controlled by phase angle modulation. The motor of a commercial professional vacuum cleaner (PVC) served as a standard source of the particles. Total number concentrations were measured with a condensation particle counter (CNC), number size distributions with a scanning mobility particle sizer (SMPS) and with a portable optical aerosol spectrometer (PAS). Impactor samples were collected to determine the size-segregated concentrations of mass and of copper. The total number concentration produced by the motor operated at full power input (Click to view the MathML source, rotational speed Click to view the MathML source) in a test room (volume Click to view the MathML source, air exchange rate Click to view the MathML source) saturates rapidly at Click to view the MathML source within 15 min of operation. The concentrations of the total mass and of copper were, at an air exchange rate of Click to view the MathML source, 146 and Click to view the MathML source, respectively. With a simple box model these concentrations correspond to emission rates of the motor of Click to view the MathML source, Click to view the MathML source of total mass and Click to view the MathML source of copper. When phase angle modulation was employed to reduce the power input of the motor, the number concentration was found to be nearly proportional to the jump in the applied voltage and the total number concentration increased by up to a factor of 5 at a rotational speed of Click to view the MathML source (power input Click to view the MathML source). The number size distributions indicated that the phase angle modulation increases mainly the emissions of ultrafine particles (UFPs) and the impactor samples suggest that these UFPs consist nearly entirely of copper. AU - Szymczak, W. AU - Menzel, N. AU - Keck, L. C1 - 5332 C2 - 24399 SP - 520-531 TI - Emission of ultrafine copper particles by universal motors controlled by phase angle modulation. JO - J. Aerosol Sci. VL - 38 IS - 5 PB - Elsevier PY - 2007 SN - 0021-8502 ER - TY - JOUR AU - Keck, L. AU - Wittmaack, K. C1 - 3282 C2 - 23924 SP - 1165-1173 TI - Miniature parallel-plate denuder for the collection of inorganic trace gases and their removal from aerosol-laden air. JO - J. Aerosol Sci. VL - 37 PY - 2006 SN - 0021-8502 ER - TY - JOUR AU - Möller, W. AU - Felten, K. AU - Seitz, J.* AU - Sommerer, K.* AU - Takenaka, S. AU - Wiebert, P.* AU - Philipson, K.* AU - Svartengren, M.* AU - Kreyling, W.G. C1 - 3281 C2 - 23598 SP - 631-644 TI - A generator for the production of radiolabelled ultrafine carbonaceous particles for deposition and clearance studies in the respiratory tract. JO - J. Aerosol Sci. VL - 37 PY - 2006 SN - 0021-8502 ER - TY - JOUR AU - Bitterle, E. AU - Hofer, T.P. AU - Karg, E.W. AU - Ferron, G.A. AU - Schröppel, A. AU - Tippe, A. AU - Geffers, R.* AU - Kreyling, W.G. AU - Maier, K.L. AU - Heyder, J. C1 - 2426 C2 - 22076 SP - 1111-1112 TI - A new in-vitro device for exposure of epithelial cells to airborne ultrafine elemental carbon particles at the air-liquid interface. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Ferge, T. AU - Mühlberger, F. AU - Zimmermann, R. C1 - 2670 C2 - 22515 SP - 425-426 TI - Laser desorption/ionization using vacuum-UV single photon ionization for analysis of organic components in tobacco smoke and ambient aerosols. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Ferge, T. AU - Karg, E.W. AU - Schröppel, A. AU - Tobias, H.* AU - Frank, M.* AU - Gard, E.* AU - Zimmermann, R. C1 - 4329 C2 - 22507 SP - 1169-1170 TI - Single particle analysis of standard soot samples for fast determination of EC/OC values. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Ferge, T. AU - Maguhn, J. AU - Hafner, K. AU - Mühlberger, F. AU - Davidovic, M.* AU - Zimmermann, R. C1 - 4330 C2 - 22514 SP - 1087-1088 TI - Correlation of gas-phase composition and particle emission during combustion of wood and model waste in a small batch reactor. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Roth, C. AU - Heyder, J. C1 - 3298 C2 - 22071 SP - 1265-1266 TI - Drug targeting in the human respiratory tract. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Semmler, M. AU - Möller, W. C1 - 2425 C2 - 22070 SP - 1155-1156 TI - Health effects of ultrafine particles. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Möller, W. AU - Felten, K. AU - Seitz, J.* AU - Sommerer, K.* AU - Takenaka, S. AU - Wiebert, P.* AU - Philipson, K.* AU - Svartengren, M.* AU - Kreyling, W.G. C1 - 4325 C2 - 22073 SP - 279-280 TI - Modified technegas generator to produce 99mTc-labeled ultrafine carbon particles for deposition and clearance studies in the respiratory tract. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Szymczak, W. AU - Kreyling, W.G. AU - Seitz, J. AU - Wittmaack, K. C1 - 4326 C2 - 22072 SP - 37-38 TI - Mass spectrometry characterisation of pure and mixed ultrafine particles of iridium and carbon. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Welthagen, W. AU - Schnelle-Kreis, J.* AU - Zimmermann, R. C1 - 4328 C2 - 22504 SP - 17-19 TI - Group classification method for PM2.5 aerosols analysed with comprehensive two-dimensional gas chromatography (GCxGC TOF MS). JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Wittmaack, K. C1 - 2556 C2 - 22281 SP - 611-620 TI - Towards a realistic description of the contribution of primary and secondary aerosols to ambient particle number and mass distributions. JO - J. Aerosol Sci. VL - 35 PY - 2004 SN - 0021-8502 ER - TY - JOUR AU - Ferge, T. AU - Nordsieck, H.* AU - Neuer-Etscheidt, K.* AU - Maguhn, J. AU - Zimmermann, R. C1 - 9483 C2 - 21480 SP - S1261-S1262 TI - Application of a photoelectric aerosol sensor (PAS) for monitoring combustion process in industrial scale incinerators. JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Ferge, T. AU - Maguhn, J. AU - Zimmermann, R. C1 - 9484 C2 - 21481 SP - S1327-S1328 TI - Performance and efficiency an electrostatic precipitator in a sludge incineration plant during different rapping cycles. JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Ferge, T. AU - Maguhn, J. AU - Hafner, K. AU - Mühlberger, F. AU - Zimmermann, R. AU - Kettrup, A. C1 - 9486 C2 - 21483 SP - S1443-S1444 TI - Correlation of the size distribution of combustion aerosols with chemical information of emitted particles and the combustion of the gas phase. JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Gallavardin, S. AU - Ferge, T. AU - Zimmermann, R. C1 - 9482 C2 - 21479 SP - S945-S946 TI - A mobile and modular single particle laser desorption/ionisation time of flight mass spectrometer for analysis of combustion aerosols at incineration plants. JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Hauler, T.E. AU - Kaesdorf, S.* AU - Boesl, U.* AU - Zimmermann, R. C1 - 8887 C2 - 21478 SP - S943-S944 TI - A novel laser mass spectrometer for characterisation of organic components in gas and particulate phase of combustion aerosols. JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Schnelle-Kreis, J.* AU - Zimmermann, R. C1 - 9489 C2 - 21477 SP - S89-S90 TI - Characterization of semi-volatile organic compounds in ambient air particulate matter (PM2.5) by direct thermal desorption -gas chromatography - time-of-flight mass spectrometry. JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Zimmermann, R. AU - Parry, R.* AU - Schnelle-Kreis, J.* C1 - 9485 C2 - 21482 SP - S1441-S1442 TI - Application of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOF) for characterization of organic compounds in ambient air particulate matter (PM2.5). JO - J. Aerosol Sci. VL - 34 PB - Elsevier PY - 2003 SN - 0021-8502 ER - TY - JOUR AU - Tippe, A. AU - Heinzmann, U. AU - Roth, C. C1 - 10119 C2 - 20527 SP - 207-218 TI - Deposition of fine and ultrafine aerosol particles during exposure at the air/cell interface. JO - J. Aerosol Sci. VL - 33 PY - 2002 SN - 0021-8502 ER - TY - JOUR AB - The concept of size-differential sampling of aerosol particles and the methods of data evaluation and presentation are reconsidered. Starting with a careful definition of logarithmically equidistant sampling intervals, the differences between mean interval positions and mean particle sizes are outlined. It is shown that for reason of particle-number conservation, log-differential concentration distributions, dN/d log D, must be presented as a function of log D, not as a function of the particle size D. Procedures for evaluating low-resolution (impactor-type) data are discussed. The properties of lognormal model distributions are analysed with the aim of evaluating the relation between concentration distributions and the derived distributions of joint length, surface area and volume. One important result is that for relatively narrow distributions the spacing between the distributions of the surface area and the volume (or mass) may be too small to be detectable experimentally. The findings derived from the basic investigation are used to evaluate recently reported particle-concentration distributions of urban aerosols which exhibit a very rapid decrease at particle sizes between 0.4 and 0.8 mum. As a result, the peak positions of the (calculated) distributions of the surface area and mass as well as large fractions of the cumulative distributions around the median differ by only 20%, a difference that cannot be identified by currently available techniques. Methods to derive information on particle sizes from combined time-dependent measurements of total particle concentrations and mass are discussed. Also addressed are the problems associated with attempts to determine the mass density of aerosol particles. AU - Wittmaack, K. C1 - 10118 C2 - 20440 SP - 1009-1025 TI - Advanced evaluation of size-differential distributions of aerosol particles. JO - J. Aerosol Sci. VL - 33 PB - Elsevier PY - 2002 SN - 0021-8502 ER - TY - JOUR AU - Maguhn, J. AU - Zimmermann, R. AU - Karg, E.W. AU - Kettrup, A. C1 - 21433 C2 - 19550 SP - 873-874 TI - On-line measurement of the particle-size distribution in the stack gas of a waste incineration plant. JO - J. Aerosol Sci. VL - 31 (Suppl.1) PY - 2000 SN - 0021-8502 ER - TY - JOUR AU - Zimmermann, R. AU - Maguhn, J. AU - Kettrup, A. C1 - 21432 C2 - 19549 SP - 622-623 TI - On-line analysis of combustion aerosols in the state of formation (900-300COD,1,248C) at industrial incinerators. JO - J. Aerosol Sci. VL - 31 (Suppl.1) PY - 2000 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Karg, E.W. AU - Busch, B. AU - Heyder, J. C1 - 28369 C2 - 33336 SP - S19-S20 TI - Hygroscopicity of ambient particles. JO - J. Aerosol Sci. VL - 30 PY - 1999 SN - 0021-8502 ER - TY - JOUR AU - Ziesenis, A. AU - Karg, E.W. AU - Korbel, R.E. AU - Kreyling, W.G. AU - Maier, K.L. AU - Ostermaier, S. AU - Roth, C. AU - Schulz, H. AU - Takenaka, S. AU - Heyder, J. C1 - 33103 C2 - 35487 SP - S995-S996 TI - Do inhaled ultrafine particles cause acute health effects in rats? III: Biological responses. JO - J. Aerosol Sci. VL - 29 IS - SUPPL.2 PY - 1998 SN - 0021-8502 ER - TY - JOUR AU - Heyder, J. AU - Beck-Speier, I. AU - Dirscherl, P. AU - Ferron, G.A. AU - Karg, E.W. AU - Kreyling, W.G. AU - Lenz, A.-G. AU - Maier, K.L. AU - Schulz, H. AU - Takenaka, S. AU - Ziesenis, A. C1 - 40068 C2 - 38347 SP - 551 TI - 31.O.03 Responses of the canine lungs during long-term exposure to a neutral sulfite and an acidic sulfate aerosol at low concentrations. JO - J. Aerosol Sci. VL - 25 IS - SUPPL. 1 PY - 1994 SN - 0021-8502 ER - TY - JOUR AU - Scheuch, G. AU - Stahlhofen, W. C1 - 40041 C2 - 37857 SP - 553-554 TI - Aerosol dispersion in human airways during one breathing cycle: The dependence of the aerosol penetration. JO - J. Aerosol Sci. VL - 25 PY - 1994 SN - 0021-8502 ER - TY - JOUR AU - Siekmeier, R. AU - Kronenberger, H.* AU - Stahlhofen, W. C1 - 40035 C2 - 38068 SP - 499-500 TI - 29.P.15 The effect of inhaled ipratropiumbromide powder on aerosol derived effective airway dimensions. JO - J. Aerosol Sci. VL - 25 IS - SUPPL. 1 PY - 1994 SN - 0021-8502 ER - TY - JOUR AU - Wagenpfeil, F. AU - Härtl, T. AU - Tschiersch, J. C1 - 40050 C2 - 0 SP - 111-112 TI - 14.P.01 Size-fractionating sampler for giant particles. JO - J. Aerosol Sci. VL - 25 IS - SUPPL. 1 PY - 1994 SN - 0021-8502 ER - TY - JOUR AB - Regional deposition of an arbitrary hygroscopic material is estimated by interpolation of deposition efficiencies previously calculated using a hygroscopic particle lung deposition (HPLD) model by Ferron et al. (J. Aerosol Sci., 1988, 19, 611) for spheres of NaCl, ZnSO4· 7H2O and a non-hygroscopic material in the range of 0.1 and 10 μm aerodynamic diameter. The interpolation is performed for the aerodynamic growth factors of the materials for each individual airway generation. A polydisperse size distribution is simulated by using discrete monodisperse fractions. Applying the estimation method to the deposition of monodisperse and polydisperse CoCl2·6H2O particles, deposition differs by less than 13% from the values obtained from the HPLD model. Two modifications of the estimation model are described: one using the equivalent growth factor instead of the aerodynamic growth factor and the other using the deposition efficiencies of NaCl and a non-hygroscopic material instead of the three materials mentioned above. The first modification gives similar results and the second modification gives larger differences up to 20% if compared with the deposition efficiencies obtained with the HPLD model. The estimation method is easier to handle than the HPLD model. AU - Ferron, G.A. AU - Karg, E.W. AU - Peter, J.E. C1 - 40320 C2 - 40085 SP - 655-670 TI - Estimation of deposition of polydisperse hygroscopic aerosols in the human respiratory tract. JO - J. Aerosol Sci. VL - 24 IS - 5 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Thoma, M.* AU - Schulz, A. C1 - 40357 C2 - 38002 SP - S471-S472 TI - 36 P 13 Transient airflows in two-dimensional bifurcations. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Frank, G. AU - Tschiersch, J. C1 - 40414 C2 - 37988 SP - S483-S484 TI - 37 P 03 Dye concentrations in fluorescent MAGE aerosol. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Heibel, T. AU - Gebhart, J. AU - Schumacher, D.* C1 - 40469 C2 - 37862 SP - S221-S222 TI - Use of Rayleigh scattering ratios to determine the refractive index of small particles. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Heyder, J. AU - Brand, P. AU - Dua, S.K. AU - Karg, E.W. C1 - 40457 C2 - 0 SP - S185 TI - 20 P 05 Gravitational particle transport in pure gases and gas mixtures. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Heyder, J. C1 - 40462 C2 - 40113 SP - S351-S352 TI - 31 I 08 A new physical concept in aerosol therapy. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Karg, E.W. C1 - 40471 C2 - 37864 SP - S511-S512 TI - Modeling of an aerosol transport system. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Ferron, G.A. C1 - 40405 C2 - 40032 SP - S451-S452 TI - 36 P 03 A miniature jet nebulizer for aerosol bolus delivery to respiratory airways via bronchoscopy. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Kronenberger, H.* AU - Siekmeier, R. AU - Schiller-Scotland, C.F.* AU - Gebhart, J. C1 - 40382 C2 - 40068 SP - S453-S454 TI - 36 P 04 Effect of bronchodilation with the beta2-agonist formoterol on convective gas transport in young healthy smokers. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Risse, U. AU - Flammenkamp, E. AU - Kettrup, A. C1 - 40474 C2 - 40036 SP - S203-S204 TI - 19 P 08 Experimental characterization of sampling systems with dynamically generated multi component test gases. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Roth, C. AU - Scheuch, G. AU - Stahlhofen, W. C1 - 40418 C2 - 37983 SP - S95-S96 TI - 14 O 04 Clearance of the human lungs for ultrafine particles. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Roth, C. AU - Gebhart, J. C1 - 40466 C2 - 40116 SP - S449-S450 TI - 36 P 02 Output of medical jet nebulizers in dependence on their design and the drug solution characteristics. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Scheuch, G. AU - Stahlhofen, W. AU - Fang, C.* AU - Lippmann, M.* C1 - 40460 C2 - 40111 SP - S355-S356 TI - 32 O 02 Aerosol recovery after bolus inhalations into an airway cast. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Schiller-Scotland, C.F.* AU - Siekmeier, R. C1 - 40461 C2 - 40112 SP - S475-S476 TI - 36 P 15 Correlation between aerosol derived airspace dimensions and airway resistance in the case of pharmacon induced bronchoconstriction. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Schiller-Scotland, C.F.* AU - Siekmeier, R. C1 - 40463 C2 - 40114 SP - S465-S466 TI - 36 P 10 The effect of inhaled terbutaline sulfate powder on aerosol derived airspace dimensions. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Siekmeier, R. AU - Schiller-Scotland, C.F.* AU - Gebhart, J. C1 - 40458 C2 - 40109 SP - S447-S448 TI - 36 P 01 Influence of experimental changes of lung inflation on pulmonary convective gas transport. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Siekmeier, R. AU - Schiller-Scotland, C.F.* AU - Stahlhofen, W. C1 - 40465 C2 - 40117 SP - S467-S468 TI - 36 P 11 Biological tolerance of inhaled 0.8 micrometer diethyl-hexyl-sebacate particles in men. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Spahn, U.* AU - Schiller-Scotland, C.F.* AU - Gebhart, J. C1 - 40467 C2 - 37975 SP - S215-S216 TI - 20 P 06 Effect of photophoresis during the observation of aerosols in a sedimentation cell. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Thomas, A.J. AU - Gebhart, J. AU - Müller, J.P.H.* C1 - 40420 C2 - 40041 SP - S117-S118 TI - 16 O 05 Effect of relative humidity on light scattering of atmospheric aerosols. JO - J. Aerosol Sci. VL - 24 IS - SUPPL. 1 PY - 1993 SN - 0021-8502 ER - TY - JOUR AU - Westenberger, S. AU - Gebhart, J. C1 - 40470 C2 - 37863 SP - S223-S224 TI - An automated Tyndall-spectrometer for the size evaluation of monodisperse aerosols. JO - J. Aerosol Sci. VL - 24 PY - 1993 SN - 0021-8502 ER - TY - JOUR AB - A method has been presented (Ferron et al., J. Aerosol Sci. 1991, 22, S863) to estimate the deposition of polydisperse hygroscopic aerosol particles in the human respiratory tract. This method uses data obtained from a hygroscopic particle lung deposition (HPLD) model (Ferron et al., J. Aerosol Sci. 1988, 19, 611). Here errors in this calculation method are estimated by comparing data obtained with the estimation method and data calculated with the HPLD model for CoCl2.6H20 particles. These differences are normally less than 10% for monodisperse and polydisperse aerosols. This estimation method is more easy to handle with respect to the HPLD model. AU - Ferron, G.A. AU - Karg, E.W. AU - Rudolf, G. C1 - 40559 C2 - 13687 SP - 465-468 TI - Deposition of polydisperse hygroscopic aerosol particles in the human respiratory tract: Estimation of errors in the calculation methods. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - To study the influence of diffusive effects on the washout of atmosheric aerosol particles an investigation has been performed at low precipitation intensities. The below cloud scavenging of aerosol has been measured in field experiments using monodisperse aerosol tagged with fluorescent dye tracer. It has been found that at low rainfall intensities diffusion is the most effective scavenging process for particles in the micrometer range. AU - Frank, G. AU - Tschiersch, J. C1 - 40508 C2 - 38733 SP - 885-888 TI - Parametrisation of below cloud scavenging at low precipitation intensities by using a fluorescent tracer method. JO - J. Aerosol Sci. VL - 23 IS - Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AU - Gebhart, J. C1 - 20211 C2 - 0 TI - To the Relevant Diamter of Aerosol Particles in the 0.1 to 1 um Transition Range. JO - J. Aerosol Sci. VL - 23, Suppl. 1 IS - 305–308 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - Modern techniques used for particle sizing in the 0.1 to 1 μm transition range are based on different kinds of forces acting upon the particles. In a spiral centrifuge or a low pressure cascade impactor particles are exposed to mechanical forces and can be classified according to their aerodynamic diameter down to about 0.08 resp. 0.03 μm. In a differential mobility analyzer (DMA) particles are separated by electrical forces up to particle diameters of about 1 μm. Submicron particles below about 0.4 μm are often measured in diffusion batteries where particles are classified according to their diffusion coefficient. The diameter derived from the electrical mobility and from the diffusion coefficient can be combined to a common mobility diameter which is only a function of the geometrical particle dimensions. When studying particle behaviour in aerosol systems one has to be cautious in all cases where the forces acting upon the particles during the experiments differ from those ones used for their size characterization. To demonstrate this problem number size distributions of atmospheric aerosols are considered and particle deposition studies in human lungs are reported. AU - Gebhart, J. C1 - 40601 C2 - 38755 SP - 305-308 TI - To the relevant diameter of aerosol particles in the 0.1 to 1 μM transition range. JO - J. Aerosol Sci. VL - 23 IS - Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AU - Karg, E.W. AU - Dua, S.K. AU - Ferron, G.A. AU - Heyder, J. C1 - 20018 C2 - 13186 SP - 389–392 TI - Performance of a Differential Mobility Analyser at Different Gas Compositions. JO - J. Aerosol Sci. VL - 23, Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - Four large whole-body exposure chambers, 19 m3 in volume, are available at this research centre for studies on the effect on lungs following long-term exposure to particulate air pollutants. Each chamber is designed to house up to five beagle dogs according to the floor space requirements for dogs, thus up to 20 dogs are available for one exposure experiment. Clean air is supplied by an air conditioning system with particle, charcoal and adsorbent filters. A horizontal air flow design provides uniform distribution of aerosol, temperature and relative humidity in the chambers with long-term stability. Data acquisition is fully automated. Alarms are available to warn of deviations from airflow settings and aerosol mass concentration. The design of the chambers and their performance during a 290 day exposure are described in this paper. AU - Karg, E.W.* AU - Tuch, T.H.* AU - Ferron, G.A.* AU - Haider, B. AU - Kreyling, W.G.* AU - Peter, J.E. AU - Ruprecht, L. AU - Heyder, J.* C1 - 40553 C2 - 38019 SP - 279-290 TI - Design, operation and performance of whole body chambers for long-term aerosol exposure of large experimental animals. JO - J. Aerosol Sci. VL - 23 IS - 3 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - A differential mobility analyzer (DMA) was tested at different compositions of aerosol and sheath gas flow using monodisperse polystyrene latex particles. The actual size of the particles had been determined by scanning electron microscopy. We found that different conditions of relative humidity in aerosol and sheath flow in the DMA cause changes less than 3% in particle size. Different gas compositions (air and nitrogen, air and carbon dioxide and air and helium) result in a change of particle size less than 6% if the density ratio k of aerosol and sheath flow is close to one (0.95 < k < 1.05). For ratios of k much smaller or larger than one the changes depend on the gas used for the composition. They may range from poor resolution to no resolution at all. AU - Karg, E.W. AU - Dua, S.K. AU - Ferron, G.A. C1 - 40640 C2 - 38914 SP - 389-392 TI - Performance of a differential mobility analyzer at different gas compositions. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Dietl, F. AU - Krombach, F. AU - Neuner, M. AU - Rosenbruch, M. C1 - 20017 C2 - 13185 SP - 507–510 TI - Retained Particle Burden in the Lings of Monkeys After Chronic Quartz Dust Expose. JO - J. Aerosol Sci. VL - 23, Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - A chronic exposure study was designed simulating conditions of modern tunneling construction in which a hyperbaric atmosphere was combined with shotscrete lining methods producing a silicate aerosol at high relative humidity. Monkeys were exposed to either a DQ12 quartz dust concentration of 10 mg/m3 or a hyperbaric atmosphere at 2500 hPa or a combination of both over 26 months. All quartz-exposed monkeys developed silicosis. In this part of the study the retained mass of quartz dust was determined in the lungs using an O2 plasma ashing technique. Quartz concentrations of 7.05 ± 2.78 mg/g and 11.14 ± 3.29 mg/g dry lung tissue was found in the quartz-exposed group and in the quartz-exposed group at hyperbaria, respectively. Although the quartz concentration was rather homogeneous in a given lung, differences in the quartz concentration between individual animals indicated a sustained variation in deposition in the lungs and/or clearance from the lungs. AU - Kreyling, W.G.* AU - Dietl, F. AU - Neuner, M.* AU - Rosenbruch, M.* AU - Krombach, F.P.* C1 - 40510 C2 - 38798 SP - 507-510 TI - Retained particle burden in the lungs of monkeys after chronic quartz dust exposure. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - To compare the initial anatomic sites of particle deposition with the resultant particle clearance kinetics in the lungs, it is desirable to have particles that have both radioactive and fluorescent labels. The radioactivity allows for analysis of in vivo retention by gamma camera; the fluorescence allows for analysis of post mortem lung tissue samples by fluorescence microscopy. We made solid monodisperse carnauba wax particles labelled with 99mTc and either coumarin 1 (a fluorescent blue dye) or coumarin 6 (a fluorescent yellow dye) using an evaporation-condensation aerosol generator. Particles could be made between 1 and 4 μm and at number concentrations of 106 to 107 cm-3. The solid particles remained stable in the lungs for 3 days, and the radioactive and fluorescent labels appeared to remain with the particles. The fluorescent label was homogeneous throughout the matrix. AU - Kreyling, W.G. AU - Blanchard, J.D.* AU - Yu, R.C.* AU - Sweeney, T.D.* C1 - 40676 C2 - 38901 SP - 181-184 TI - Production of monodisperse, fluorescently and radioactively labelled aerosol particles. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - The models used in magnetopneumography and in cytomagnetometry to estimate the intracellular viscosity and the energy of the cell motiliy are tested with monodisperse and with polydisperse ferrimagnetic micro particles, suspended in highly viscous Newtonian solutions. Using polydisperse particles deviations from an exponential decay were measured. In relaxation and in viscosity measurements the particles behave with an increased hydrodynamic volume. AU - Möller, W.D. AU - Stahlhofen, W. AU - Wiegand, J. C1 - 40684 C2 - 38894 SP - 421-424 TI - Measurement of hydrodynamic properties of highly viscous solutions with ferrimagnetic micro-particles. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - According to the method of Rapaport-Weinstock an aerosol generator was constructed with a joint vapour and nuclei source. The generator is ready for operation after a few minutes, and the modal diameter of the aerosol size distribution can be changed in the same time. Theoretical considerations for the best operating conditions of the generator are given. Experimental results show the dependence of the particle size distribution on the different operating parameters. The number concentration of the produced aerosol is more than 106 cm-3, the geometric standard deviation less than 1.10, and the particle diameter is varied between 0.2 and 2 μm, but this range can be extended. AU - Roth, C. AU - Gebhart, J. AU - Reisert, W. C1 - 40667 C2 - 38885 SP - 185-188 TI - The production of high-concentrated monodisperse aerosols with variable size distributions. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - Aerosol particles with aerodynamic diameters (dac) of about 1.1 μm were inspired into human conducting airways by the bolus inhalation technique. Inhaling small volumes of aerosols ("20 cm3 - boluses") at the very end of a clean air inhalation these particles should only reach conducting human airways. Particle recoveries (RC) in the exhaled air after various periods of breath holding (tb) were measured in front of the mouth with an aerosol laser photometer. Assuming that losses of the inhaled particles were caused by sedimentation during breath holding periods, the slope of the recovery function (RC(tb)) is a measure of the airway dimensions where the particles were located at end inhalation. This function can be estimated theoretically. By comparing bolus recovery data to model calculations, assuming different aerosol distributions in airway models, and both still and stirred settling, it could be shown that aerosol boluses inhaled to lung depths < 40 cm3 do not reach alveolar airspaces during inhalation. AU - Scheuch, G. AU - Stahlhofen, W. C1 - 40499 C2 - 38535 SP - 477-481 TI - The recovery of 1μm aerosol particles from large human airways. JO - J. Aerosol Sci. VL - 23 IS - Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - Medical doctors found out that in comparison to adults the number of children with airways desease due to air pollution is much higher. However up to now experimentally data for total deposition of aerosol particles in the human respiratory tract are predominantly published for adults. In the present study 29 children with normal lung function data volunteered for the determination of total deposition using an inline inhalation technique. It turns out that total deposition data for children are higher than for adults, and thus confirm a general tendency already reported by BECQUEMIN et al. (1986). Using the inline technique the differences in deposition values between children and adults are more pronounced than found by those authors. AU - Schiller-Scotland, C.F.* AU - Hlawa, R. AU - Gebhart, J. AU - Wönne, R.* AU - Heyder, J. C1 - 40549 C2 - 38782 SP - 457-460 TI - Total deposition of aerosol particles in the respiratory tract of children during spontaneous and controlled mouth breathing. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - Aerosol particles of about 0.8 μm diameter behave in many respects like a non-diffusing gas and trace almost exactly the mass movement of air during a breathing cycle. By means of an inhalation apparatus which allows continuous monitoring of respiratory volumes and of aerosol concentration, changes of inhaled aerosol pulses during a respiratory cycle were studied. Aerosol pulse parameters (APP) as well as conventional pulmonary function tests (PFT) were evaluated for 32 healthy nonsmokers (NS) and 32 severe smokers (S). APP and PFT were compared to rule out the discriminative potential of the different methods for the detection of early changes of abnormal lung ventilation. Conventional pulmonary function tests of all subjects were within the normal limits. Slight but significant differences between NS and S were found for MEF25 and FRC. In contrast most of the APP showed highly significant differences between NS and S. Therefore it is concluded, that the determination of APP may be more sensitive to detect early changes in pulmonary function tests as bodyplethysmography and spirometry. AU - Siekmeier, R. AU - Schiller-Scotland, C.F. AU - Kronenberger, H.* AU - Gebhart, J. C1 - 40520 C2 - 38793 SP - 483-486 TI - Use of aerosol pulse parameters as a sensitive discriminator between middle-aged healthy smokers and nonsmokers. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - A non-invasive aerosol method allows the determination of effective airway dimensions (EADs) as a function of volumetric lung depth (VLD). Anatomical methods have shown that airway morphometry is affected by body height, lung volume and lung inflation. This study was performed to investigate the effect of these parameters on aerosol derived EADs. In all subjects EADs were determined twice at two different lung inflations to allow normalization of EADs at 80 % TLC. The study group has been divided into two subgroups of low (n=6) and high (n=5) TLC and body height. Before normalization EADs of the two subgroups were not significantly different and no significant correlations between EADs and anthropometric data were found. The described differences and correlations got significant after normalization of EADs at 80 % TLC. The results confirm, that EADs are a function of anthropometric data and individual lung inflation and should be normalized. AU - Siekmeier, R. AU - Schiller-Scotland, C.F. AU - Kronenberger, H.* AU - Gebhart, J. C1 - 40664 C2 - 40024 SP - 487-490 TI - Standardization of individual lung inflation and its effect on aerosol derived effective airway dimensions. JO - J. Aerosol Sci. VL - 23 IS - Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AU - Trautner, F. AU - Huber, K. AU - Niessner, R. C1 - 20274 C2 - 13462 SP - 99-1002 TI - Appearance and Concentration Ranges of Atrazine in Spring Time Cloud and Rainwater from the Vosges (France). JO - J. Aerosol Sci. VL - 23 (Suppl.1) PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - In order to observe changes in size distribution and chemical composition of aerosol particles during the formation of orographic clouds size segregated aerosol samples were collected at two sites of different altitudes in the west of the Vosges. Number size distributions covering a size range between 0.001 and 0.8 μm were monitored by means of a CNC - diffusion-battery-(CNC-DB) setup located at a site in the condensation level. During the condensation phase a growth of the small particles is observed. After the cloud event the aerosol does not recover it's original diameter. At the same time the mass of Sulfur in the aerosol in the small size range is elevated leading to a smaller Mass median diameter (MMD) of the Sulfur size distribution measured with a Berner impactor. The reason for this enrichment is an uptake of Sulfur from the gasphase during the cloud formation. AU - Trautner, F. AU - Pohlmann, G.* AU - Reis, M.M.* AU - Repsold, U. AU - Hietel, B. AU - Schulz, F. AU - Tschiersch, J. AU - Holländer, W.* C1 - 40496 C2 - 38537 SP - 937-940 TI - Determination of the size segregated chemical composition and on line size distribution measurement of aerosol during cloud formation. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - During a measuring campaign in springtime 1991 (NUAC '91) cloud and rainwater was collected from airmasses of atlantic origin at the west side of the Vosges. Atrazine analysis of the samples using an ELISA showed atrazine concentrations in cloudwater between 24 and 260 ng/l and in rainwater between 9 and 137 ng/l. The origin of the atrazine was probably the farmland between Paris and the Vosges where intensive maize cultivation is done. AU - Trautner, F. AU - Huber, K.J.* AU - Nießner, R.* C1 - 40543 C2 - 38785 SP - 999-1002 TI - Appearance and concentration ranges of atrazine in spring time cloud and rainwater from the Vosges France. JO - J. Aerosol Sci. VL - 23 IS - SUPPL. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - Aerosol pulses injected into particle-free air at predetermined volumes during inspiration have proved as useful tools in lung diagnostics. For the generation and recording of sharp aerosol-pulses a new inhalation device consisting of a valve system with pneumatic elements and a miniaturized photometer has been developed. The new apparatus is capable to generate and record sharp aerosol micro-pulses down to 15 cm3. AU - Westenberger, S. AU - Gebhart, J. AU - Jaser, S.* AU - Knoch, M.* AU - Köstler, R.* C1 - 40660 C2 - 40022 SP - 449-452 TI - A novel device for the generation and recording of aerosol micro-pulses in lung diagnostic. JO - J. Aerosol Sci. VL - 23 IS - Suppl. 1 PY - 1992 SN - 0021-8502 ER - TY - JOUR AB - This contribution describes the tested possibilities of a computational fluid dynamics(CFD) software package (FIDAP) to determine airflows in combination with heat and water vapour transport in two dimensional bifurcations simulating human lung bifurcations. AU - Ferron, G.A. AU - Hillebrecht, A. AU - Peter, J.E. AU - Priesack, E. AU - Thoma, M. AU - Künzer, I. AU - Mederer, R. AU - Klump, U.G. C1 - 40742 C2 - 38964 SP - S809-S812 TI - Airflow simulation in two-dimensional bifurcations. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - A standardized method is described to determine the mucociliary clearance of monodisperse insoluble 111In labelled polystyrene particles in the upper airways of anesthetized dogs. 60 μl of particle suspension are dispersed through a nozzle at the tip of a fiberoptic bronchoscope. The particle transport in the trachea is followed by the radioactivity movement using a gamma camera. The results for 13 dogs indicated an intraindividual subject reproducibility of about 25%. AU - Ferron, G.A. AU - Erbe, F. AU - Fürst, G.M. AU - Heilmann, P. AU - Kreyling, W.G. AU - Möllensädt, S. AU - Neuner, M. AU - Schumann, G. C1 - 40759 C2 - 38919 SP - S867-S870 TI - Measurement on mucociliary clearance in the upper airwaysof beagle dogs. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - A method is described to estimate the total and regional deposition of polydisperse aerosol particles from data on the deposition of different salt aerosol particles described in literature (Ferron et al., J. Aerosol Sci. 1988, 19, 611) and own calculations. This method is applied to estimate the regional deposition of a Na 2S 2O 5 aerosol in the human respiratory tract. AU - Ferron, G.A. AU - Dua, S.K. AU - Karg, E.W. AU - Kreyling, W.G. AU - Tuch, T.H. AU - Heyder, J. C1 - 40817 C2 - 13496 SP - S863-S866 TI - Estimation of the deposition of polydisperse hygroscopic aerosol particles in the respiratory tract. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - For the purpose of getting some detailed information about the efficiency of precipitation scavenging and its dependence on different parameters, a tracer method has been developed to measure wet deposition quantities of aerosol particles. Different parameters such as particle diameter, precipitation intensity, wind velocity and other meteorological quantities are recorded and their influence on the wet deposition processes are discussed. AU - Frank, G. AU - Trautner, F. AU - Tschiersch, J. C1 - 40808 C2 - 38724 SP - S537-S540 TI - Determination of scavenging efficiency by using fluorescent aerosol. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - Light scattering on single particles and on assembly of particles is applied for the characterization ofenvironmental aerosols on workplaces and in the common atmosphere. AU - Gebhart, J. C1 - 40712 C2 - 40166 SP - S391-S394 TI - Use of light scattering for the characterization of environmental aerosols. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - The counting efficiency of an Aerodynamic Particle Sizer has been determined in the size range of 0.5 to 1 μm Correction factors have been evaluated experimentally which should be used for the interpretation of the observed size distribution for sizes below 0.8 μm. AU - Karg, E.W. AU - Dua, S.K. AU - Tschiersch, J. C1 - 40702 C2 - 40211 SP - S351-S354 TI - Experimental counting efficiency of the TSI aerodynamic particle sizer in the submicron size range. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - An interspecies comparison of the lung clearance of a well-defined inhalable material was conducted to aid in the development of models used to relate inhalation of radioactive particles to organ doses and bioassay measurements, and in particular to aid in the extrapolation of animal data to man. It complements a previous interspecies comparison in which lung clearance of monodisperse, porous 0.8 μm and 1.7 μm diameter cobalt oxide (Co3O4) particles was followed in seven species including man (Bailey et al., J. Aerosol Sci. 20, 169-188, 1989). In the present study baboons, dogs and HMT rats were used since they had shown the most prominent differences in clearance in the previous investigation. Additionally, clearance in the human volunteers and baboons was very similar. The material selected consisted of almost solid, monodisperse 0.9 μm diameter CoP3O4 particles which were chemically similar to the materials studied previously but differed physically with a higher density and a smaller specific surface area. Lung retention and excretion of 57Co were followed for at least six months after inhalation. Lung retention at 6 months after inhalation ranged from 60% of the initial lung deposit in baboons to 5%, in rats and in all three species clearance was considerably slower than that of porous 0.8 μm Co3O4 particles. Lung clearance rates due to translocation of dissociated 57Co to the blood, S(t), and due to particle transport to the GI tract M(t) were calculated. Initially, S(t) ranged from 0.1% of the contemporary lung content day-1 in baboons to 0.7% in rats. Depending on the initial translocation rates of each species, S(t) over time followed patterns expected from a model of particle dissolution derived previously. For each species, a correlation was found between the initial translocation rates and the specific surface area of the three particles used. Estimated values of M(t) were consistent with values obtained previously with other materials. AU - Kreyling, W.G. AU - Andre, S.* AU - Collier, C.G.* AU - Ferron, G.A. AU - Métivier, H.J.* AU - Schumann, G. C1 - 40709 C2 - 40207 SP - 509-535 TI - Interspecies comparison of lung clearance after inhalation of monodisperse, solid cobalt oxide aerosol particles. JO - J. Aerosol Sci. VL - 22 IS - 4 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - Using a combined DMA-CNC-test-system for high sensitive particle counters the counting efficiency of the PMS-model HS-LAS was measured. AU - Peters, C.H.L. AU - Gebhart, J. AU - Roth, C. AU - Sehrt, S. C1 - 40740 C2 - 40190 SP - S363-S366 TI - Test of high sensitive laser particle counters with PSL-aerosols and a CNC reference. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - In order to estimate the dry deposition of the major inorganic ions to two different spruce standsthe input parameters of a model for determining the deposition velocity were continuously measured. Size specific samples of particulate matter were collected at the same sites with five-stage Berner impactors. The dry deposition flux F was calculated by multiplying these concentrations by the deposition velocity specific to each measuring interval and size class. AU - Peters, K.* AU - Ludwig, J.W.* AU - Ruoss, K. C1 - 40816 C2 - 38038 SP - S569-S572 TI - The input of inorganic ions to spruce forests by dry deposition of aerosol particles. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - The response characteristics of an intercavity light scattering instrument are calculated for coherent andincoherent superposition of the two waves illuminating the particle. Measurements with monodisperse PSL-particles show an excellent agreement with the coherent response function. AU - Reisert, W. AU - Roth, C. AU - Gebhart, J. AU - Fischer, P. AU - Schäfer, R. C1 - 33790 C2 - 40253 SP - S355-S358 TI - Intercavity laser light scattering: experimental verification of theoretical response functions. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - With a Mobile Aerosol Spectrometer variations of size distributions during differentmeteorological events were measured. The correlation between aerosol data, Nitrogene Oxide concentrations and meteorological parameters was studied. AU - Ruoss, K. AU - Karg, E.W. AU - Brand, P. C1 - 33802 C2 - 40226 SP - S629-S632 TI - Short term variations of size distributions and concentrations ofatmospheric aerosol particles. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - An exposure system was developed to measure the total deposition efficiency of airborne contaminants which may exist in the vapor, particle, or both phases of an inhaled atmosphere. A formula was derived to account for both deposition in the mouthpiece and one-way valve assembly and the volume of the assembly in the calculation of the total deposition efficiency. A human subject was exposed by mouth to three atmospheres containing either glycerol droplets with accompanying vapor, corn oil droplets of a similar size, or propylene glycol vapor. Analyses of the amounts of the exposure materials collected from a sample of the exposure air, collected from the exhaled air, and recovered from the mouthpiece provided the following average total deposition efficiencies: polydisperse 1 μm glycerol droplets and accompanying vapor 62%, polydisperse 0.8 μm corn oil droplets 19%, and propylene glycol vapor 100%. These experiments demonstrate that the total deposition efficiency of inhaled contaminants in both the particulate and vapor phases can be measured. Variations of deposition efficiency with type of material and aerosol mass concentration are discussed. AU - Soderholm, S.C.* AU - Anderson, D.A.* AU - Utell, M.J.* AU - Ferron, G.A. C1 - 40750 C2 - 38959 SP - 917-926 TI - Method of measuring the total deposition efficiency of volatile aerosols in humans. JO - J. Aerosol Sci. VL - 22 IS - 7 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - Following the demonstration of morphologic changes induced by a sulphur(IV) aerosol inthe extrapulmonary airways (Takenaka et al., 1990), the pulmonary airways were examined in order to evaluate pulmonary effects. After continuous exposure for 290 days to a respirable sulphur(IV) aerosol at a concentrationequivalent to a sulphur dioxide concentration of 0.6 mg m-3, lung samples from 8 exposed and 3 unexposed beagle dogs were prepared according to the modified cascade sampling and vertical section methods, and bronchial glands and alveolar regions were analyzed morphometrically. No differences were observed in the ratio of bronchial glands to bronchial walls between the exposure and control groups. However, the exposure group showed a slight decrease in the volume density of the septum. This decrease resulted in a reduction in the septal surface area, indicating enlargement of the alveolar air space. One of 8 exposed dogs showed clear morphologic evidence of focal dilation of the alveoli and alveolar sac. There was a significant decrease in the calculated diffusing capacity in the exposure group. These findings indicate that long-term exposure to airborne sulphur(IV) has adverseeffects on both the upper and lower parts of the respiratory system of beagle dogs. AU - Takenaka, S.* AU - Fürst, G.M.* AU - Heilmann, P.* AU - Heini, A.* AU - Heinzmann, U. AU - Kreyling, W.G.* AU - Murray, A.B. AU - Ruprecht, L. AU - Schulz, H.* AU - Heyder, J.* C1 - 40846 C2 - 38028 SP - S871-S874 TI - Long-term exposure of dogs to a sulphur(IV) aerosolV. Effects on the pulmonary morphometry. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - During wintertime 1990/91 fogwater and rime ice was collected on a polyethylene plate of0.25 m2 sho~y after sampling aerosol in eight size classes. Fog water deposition reaches up to 15. ml/m h. For elements analysed in aerosol and ter samples as well deposition velocities due to wet deposition range between 10-4 and 10-2 m/s. AU - Trautner, F. AU - Frank, G. AU - Tschiersch, J. C1 - 40737 C2 - 40188 SP - S529-S532 TI - Deposition of particle bound substances in wintertime fog. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - Dry deposition of aerosol particles to a snow surface was studied. Measured deposition velocities range from 0.1 to 2 cm/s. A pronounced dependence of the deposition velocity on particle size could not be found (size range 0.4 - 1.7 pm mass median diameter). AU - Tschiersch, J. AU - Frank, G. AU - Hietel, B. AU - Schramel, P. AU - Schulz, F. AU - Trautner, F. C1 - 40783 C2 - 38875 SP - S565-S568 TI - Aerosol deposition to a snow surface. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AB - With a new photometer, which collects light scattered in two different apertures, it is possible to discriminatebetween aerosols consisting of small (respirable) particles and aerosols also containing coarser size classes. This is shown theoretically and in experiments with monodisperse aerosols. AU - Westenberger, S. AU - Gebhart, J. AU - Heibel, T. AU - Abendroth, R. AU - Thaer, A. AU - Meuser, W. AU - Schöpplein, M. AU - Seibel, H. C1 - 40754 C2 - 38924 SP - S359-S362 TI - Detection of coarse size fractions within airborne dusts by means of light scattering ratios. JO - J. Aerosol Sci. VL - 22 IS - SUPPL. 1 PY - 1991 SN - 0021-8502 ER - TY - JOUR AU - Anselm, A.F. AU - Heibel, T. AU - Gebhart, J. AU - Ferron, G.A. C1 - 19138 C2 - 12194 SP - 427-430 TI - 'In Vivo'-Studies of Growth Factors of Sodium Chrloride Particles in the Human Respiratory Tract. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - Growth factors of hygroscopic NaCl-particles in the human respiratory tract have been determined experimentally for various diameters of the dry particles and different relative humidities (RH) during inspiration. The equilibrium diameter of the NaCl-H2O-solution droplets in the pulmonary region corresponds to RH = 99,5%. AU - Anselm, A.F. AU - Heibel, T. AU - Gebhart, J. AU - Ferron, G.A.* C1 - 42539 C2 - 40191 SP - S427-S430 TI - "In vivo"-studies of growth factors of sodium chrloride particles in the human respiratory tract. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Beck-Speier, I. AU - Kreyling, W.G. AU - Luippold, G.B. AU - Godleski, J.J. C1 - 18726 C2 - 11833 SP - 463-466 TI - Sulfite Oxidase Activity in Rat Nasal Tissue and Pathologic Response to Inhalation of Sulfur Oxides. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - To assess short term toxicity of aerosols generated from acidic (pH=3) and neutral (pH=6) sodium sulfite (Na2S2O5) solutions, 3 groups of rats were exposed to airborne concentrations of 50 mg/m-3 sulfite aerosol in a whole body exposure chamber. Acidic aerosols also contained 15-20 mg/m-3 SO2 gas. Two groups were exposed for 3 h to an acidic or a neutral aerosol, and the last group was exposed for 24 h to an acidic aerosol. Each aerosol had a mass median aerodynamic diameter of 1.1 μm and GSD of 2.1. After 3 h of exposure to neutral sulfite aerosol, the nasal epithelium had evidence of mild injury, whereas after 3 h of exposure to acidic aerosol, necrosis of the anterior nasal epithelium appeared. After 24 h of acidic sulfite aerosol exposure, necrosis of the epithelium throughout the nasal turbinates occurred accompanied by an infiltration of neutrophils. This injury by acidic sulfite aerosols correlated with very low activity of sulfite oxidase in rat nasal tissue. Although no histologic changes were found in the lung parenchyma, alveolar macrophages isolated from rats exposed to 24 h of acidic sulfite aerosol showed a reduction in their oxygen consumption by 50 %. Therefore, acidic sulfite aerosols cause marked injury to the nasal epithelium but have subtle effects on the lung parenchyma. AU - Beck-Speier, I. AU - Kreyling, W.G. AU - Luippold, G.B. AU - Godleski, J.J.* C1 - 42130 C2 - 40267 SP - S463-S466 TI - Sulfite oxidase activity in rat nasal tissue and pathologic responses to inhalation of sulfur oxides. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Kreyling, W.G. AU - Fürst, G. AU - Neuner, M. AU - Schumann, G. AU - Heyder, J. C1 - 19144 C2 - 12200 SP - 479-482 TI - Long-Term Exposure of Dogs to a Sulfite Aerosol: III. Effects olung Clearance. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - Eight dogs were exposed to a sodium bisulphite aerosol during 290 days. Lung clearance was tested with moderately soluble and insoluble aerosol particles after a single inhalation. Three dogs showed significant changes in clearance rate of moderately soluble particles during the sulphite exposure compared to the clearance rate during clean air exposure. The results were confirmed by in vitro clearance measurements in alveolar macrophages. AU - Ferron, G.A. AU - Kreyling, W.G. AU - Fürst, G.M. AU - Neuner, M. AU - Schumann, G. AU - Heyder, J. C1 - 41189 C2 - 0 SP - S479-S482 TI - Long-term exposure of dogs to a sulphite aerosol: III. Effect of lung clearance. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Frank, G. AU - Tschiersch, J. AU - Behrens, H. C1 - 18691 C2 - 11792 SP - 213-216 TI - Wet Deposition of Tracer-marked Aerosol. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - To study the import of the influential parameters on the efficiency of below-cloud-scavenging a tracer method for field experiments has been developed. To this purpose fluorescent aerosol is released at precipitation events. Precipitation samples are taken and the particle concentrations in the sample determined. Measurements at different meteorological conditions and with different aerosol particle diameters allow a parametrisation of wet deposition. AU - Frank, G. AU - Tschiersch, J. AU - Behrens, H. C1 - 42239 C2 - 40204 SP - S213-S216 TI - Wet deposition of tracer-marked aerosol. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Godleski, J.J. AU - Kreyling, W.G. AU - Schumann, G. C1 - 19146 C2 - 12202 SP - 487-490 TI - Particle Redistribution in the Lungs and Short Term Clearance After Multiple Inhalations. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - Brief sequential exposures of dogs to monodisperse, differently labelled aerosol particles of the same aerodynamic size can be used to study particle deposition, redistribution, and short term (14 days) clearance. Since the aerosols have the same aerodynamic size distribution (1.8 - 1.9 μm), the deposition pattern is the same for similar breathing patterns and, hence, the observed patterns of distribution at sacrifice indicate particle redistribution depending on the time of retention. We exposed four beagle dogs to 57Co3O4 aerosols 14 days before sacrifice. Three days before sacrifice, two dogs inhaled 67Ga2O3 particles. Immediately before sacrifice, the two other dogs received 67Ga2O3 particles. The initial 67Ga2O3 pattern showed deposition in airways and uniform parenchymal distribution. The 3 day pattern of retained 67Ga2O3 showed a striking redistribution to pleural and perivascular sites of accumulation with little evidence of airway surface retention. The 14 day pattern of retained 57Co3O4 was similar to the 3 day pattern but more pronounced in its irregular distribution. Quantification of the radiographic distribution patterns by image analysis confirmed the visual observations. We conclude that sequential aerosol exposures can be used to define and quantify patterns of pulmonary redistribution of inhaled particles. AU - Godleski, J.J.* AU - Kreyling, W.G. AU - Schumann, G. C1 - 41149 C2 - 36385 SP - S487-S490 TI - Particle redistribution in the lungs and short term clearance after multiple inhalations. JO - J. Aerosol Sci. VL - 21 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Heyder, J. AU - Beinert, T. AU - Rajathurai, A.M. C1 - 42541 C2 - 40192 SP - 347-348 TI - Intrapulmonary particle transport as a function of gas composition. JO - J. Aerosol Sci. VL - 21 IS - 3 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. C1 - 41150 C2 - 36384 SP - 371-374 TI - Aerosol particle parameters maintaining lung clearance by intracellular dissolution and translocation. JO - J. Aerosol Sci. VL - 21 IS - 3 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Maier, K.L. AU - Beck-Speier, I. AU - Dayal, N. AU - Heilmann, P. AU - Hinze, H. AU - Lenz, A.-G. AU - Leuschel, L. AU - Matjekova, E. AU - Miaskowski, U. AU - Ruprecht, L. AU - Heyder, J. C1 - 19143 C2 - 12199 SP - 475-478 TI - Long-Term Exposure of Dogs to a Sulphite Aerosol: II. Effects on Biochemical and Cellular Lung Parameters. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - During exposure of 8 Beagle dogs for 290 days to particulate sulphur(IV) no clinical symptoms were seen which could be correlated with the pollutant. However, significant changes were observed in some of the biochemical and cellular parameters in the bronchoalveolar lavage (BAL) fluid. In the second half of the exposure period the protein and albumin content of the BAL fluid increased indicating changes in the transudation kinetics of serum proteins into the alveolar lumen. The lysosomal enzyme β-N-acetyl-glucosaminidase also increased in the BAL fluid indicating a higher release of this enzyme from phagocytes. At the same time alveolar macrophages showed a reduced phagocytosis rate in vitro for polystyrene particles and a reduced production of oxygen-derived free radicals. These results indicate a reduced unspecific defence capacity of the alveolar macrophages as well as a change in their lysosomal activity. In conclusion, chronic exposure to particulate S(IV) at a low concentration can initiate pathobiochemical pathways in the lungs indicating the possibility of a health risk. AU - Maier, K.L. AU - Beck-Speier, I. AU - Dayal, N. AU - Heilmann, P. AU - Hinze, H. AU - Lenz, A.-G. AU - Leuschel, L. AU - Matjekova, E. AU - Miaskowski, U. AU - Ruprecht, L. AU - Heyder, J. C1 - 42194 C2 - 40151 SP - S475-S478 TI - Long-term exposure of dogs to a sulphite aerosol: II. Effects on biochemical and cellular lung parameters. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Möller, W. AU - Roth, C. AU - Stahlhofen, W. C1 - 19135 C2 - 12191 SP - 657-660 TI - Improved Spinning Top Aerosol-Generator for the Production of High Concentrated Ferrimagnetic Aerosols. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Roth, C. AU - Stahlhofen, W. C1 - 19134 C2 - 12190 SP - 443-446 TI - Radioactively Labelled Ultrafine Particles for Clearance Measurements. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Rudolf, G. AU - Köbrich, R. AU - Stahlhofen, W. C1 - 19133 C2 - 12189 SP - 403-406 TI - Modelling and Algebraic Formulation of Regional Aerosol Deposition in Man. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - An updated version is presented of the algebraical deposition model introduced previously. The model has been based on a statistical analysis of the data. Additional experimental data have been taken into account, and where no experimental data were available, theoretical deposition data have been used. This allowed to differentiate bronchial and bronchiolar deposition, and to include in the model the dependence of regional deposition on gender and age. Furthermore the model has been extended to describe the biological variability of the data. This model will serve as deposition standard as part of the ICRP dosimetry model. AU - Rudolf, G. AU - Köbrich, R. AU - Stahlhofen, W. C1 - 41188 C2 - 36476 SP - S403-S406 TI - Modelling and algebraic formulation of regional aerosol deposition in man. JO - J. Aerosol Sci. VL - 21 PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - The content of sulphite in atmospheric aerosol particles is investigated by filter and cascade impactor measurents. The role of atmosheric trace gases and meteorological conditions for the formation of sulphite in particles is discussed. AU - Ruoss, K. AU - Dlugi, R.* C1 - 41190 C2 - 36477 SP - S233-S236 TI - Sulphite content of atmospheric aerosol particles. JO - J. Aerosol Sci. VL - 21 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Scheuch, G. AU - Stahlhofen, W. C1 - 18585 C2 - 11719 SP - 431-434 TI - Dispersion of Aerosol Boluses in the Human Tracheo-bronchial-tract During Periods of Breathholding. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Scheuch, G. AU - Gebhart, J. AU - Roth, C. C1 - 18586 C2 - 11720 SP - 439-442 TI - Uptake of Electrical Charges in the Human Respiratory Tract During Exposure to Air Loaded with Negative Ions. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Schiller-Scotland, C.F. AU - Gebhart, J. AU - Lintl, H. AU - Siekmeier, R. AU - Kronenberger, H. C1 - 17581 C2 - 10890 SP - 419–S422 TI - Human Airway Diameters Derived from Aerosol Inhalation Studies: Reactions of Non-Smokers and Smokers to Brinchodilators. JO - J. Aerosol Sci. VL - 21, Suppl. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Schiller-Scotland, C.F. AU - Gebhart, J. AU - Lintl, H. AU - Siekmeier, R. C1 - 19140 C2 - 12196 SP - 419-422 TI - Human Airway Diameters Derived from Aerosol Inhalation Studies: Effect of Inspired Aerosol Volume and Lung Inflation. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Sieckmeier, R. AU - Schiller-Scotland, C.F. AU - Gebhart, J. AU - Kronenberger, H. C1 - 19141 C2 - 12197 SP - 423-426 TI - Pharmacon-induced Airway Obstruction in Healthy Subjects: Dose Dependent Changes of Inspired Aerosol Boluses. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Stahlhofen, W. AU - Möller, W. C1 - 17579 C2 - 10886 SP - 355–357, 359–362 TI - Relaxation Measurements with Spherical Magnetic Particles in the Human Lung. JO - J. Aerosol Sci. VL - 21, Issue3 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Stahlhofen, W. AU - Möller, W. AU - Godleski, J.J. C1 - 18181 C2 - 11391 TI - Relaxation Measurements with Spherical Magnetic Particles in the Human Lungs. JO - J. Aerosol Sci. PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Stahlhofen, W. AU - Möller, W. C1 - 19136 C2 - 12192 SP - 435-438 TI - Using Spherical Magnetic Particles for Testing the Intracellular Viscosity. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Stahlhofen, W. AU - Koebrich, R. AU - Rudolf, G. AU - Scheuch, G. C1 - 19137 C2 - 12193 SP - 407-410 TI - Short-Term and Long-Term Clearance of Particles from the Upper Human Respiratory Tract as Function of Particle Size. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Takenaka, S. AU - Heilmann, P. AU - Ruprecht, L. AU - Heinzmann, U. AU - Murray, A.B. AU - Fürst, G. AU - Heini, A. AU - Heyder, J. C1 - 19145 C2 - 12201 SP - 483-486 TI - Long-Term Exposure of Dogs to a Sulphite Aerosol: IV. Effects on Extrapulmonary Airway Morphology. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - The extrapulmonary airways of 8 male beagle dogs were examined histopathologically after continuous exposure to a sulphite aerosol at a concentration of 1 mg/m3 for 290 days. Hyperplastic foci were observed in the respiratory region of the posterior nasal cavity. The changes were characterized by a thickened epithelial layer resulting from epithelial proliferation, by a loss of secretory material and by moderate mononuclear cell infiltration. In the larynx an increased number of non-ciliated cells, and slight mononuclear cell infiltration were found. Tracheal changes were limited to an increased number of non-ciliated cells in the membranous portion. TEM (transmission electron microscopy) showed the changes in the trachea to be caused by disorder in the development of ciliated cells. These findings suggest that sulphite aerosols have adverse effects on the extrapulmonary airways of beagle dogs. AU - Takenaka, S. AU - Heilmann, P. AU - Ruprecht, L. AU - Heinzmann, U. AU - Murray, A.B. AU - Fürst, G.M. AU - Heini, A. AU - Heyder, J. C1 - 33318 C2 - 36417 SP - S483-S486 TI - Long-term exposure of dogs to a sulphite aerosol: IV. Effects on extrapulmonary airway morphology. JO - J. Aerosol Sci. VL - 21 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Trautner, F. AU - Frank, G. AU - Tschiersch, J. AU - Voigt, G. C1 - 18817 C2 - 11936 SP - 295-298 TI - A Method to Quantify wet and occult Deposition of Aerosol to Wheat Plants. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - A measuring device based on a weighing lysimeter is introduced, that allows a highly time and weight resolved registration of the change of weight due to deposition processes of rain, fog and dew. It has been tried to distinguish between the water volume taken up by the soil and intercepted by wheat plants during single rain events. Condensation of dew could be registrated during dew nights. The methodology and first results are presented. AU - Trautner, F. AU - Frank, G. AU - Tschiersch, J. AU - Voigt, G.M. C1 - 41205 C2 - 36481 SP - S295-S298 TI - A method to quantify wet and occult deposition of aerosol to wheat plants. JO - J. Aerosol Sci. VL - 21 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Tschiersch, J. AU - Hietel, B. AU - Schramel, P. AU - Trautner, F. C1 - 19139 C2 - 12195 SP - 357-360 TI - Saharan dust at Jungfraujoch. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Tschiersch, J. AU - Hietel, B. AU - Schramel, P. AU - Trautner, F. C1 - 42193 C2 - 40248 SP - S357-S360 TI - Saharan dust at jungfraujoch. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AU - Tuch, T. AU - Ferron, G.A. AU - Karg, E.W. AU - Kreyling, W.G. AU - Heyder, J. C1 - 19142 C2 - 12198 SP - 471-474 TI - Long-Term Exposure of Dogs to a Sulphite Aerosol: I. Rationale and Design Parameters. JO - J. Aerosol Sci. VL - 21 (Suppl.1) PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - Eight Beagle dogs were exposed to a sodium bisulphite aerosol at a concentration of 1 mg m -3 for a period of 290 days. This paper summarizes the design, the facilities and the exposure conditions of the exposure experiment. AU - Tuch, T.H. AU - Ferron, G.A. AU - Karg, E.W. AU - Kreyling, W.G. AU - Heyder, J. C1 - 42065 C2 - 40275 SP - S471-S474 TI - Long-term exposure of dogs to a sulphite aerosol: I. Rationale and design parameters. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - To monitore droplet production of the vibrating orifice aerosol generator (VOAG) continously an optical droplet control has been developed on the bases of laser light extinction. The monodispersity of the droplets, the presence of satellites as well as bi - or multi - modal structures of the size distribution can be identified on the display of a oscilloscope. AU - Westenberger, S. AU - Heibel, T. AU - Gebhart, J. AU - Roth, C. C1 - 42197 C2 - 40146 SP - S547-S550 TI - Continuous monitoring of droplet production of a vibrating orifice generator by laser light extinction. JO - J. Aerosol Sci. VL - 21 IS - SUPPL. 1 PY - 1990 SN - 0021-8502 ER - TY - JOUR AB - An interspecies comparison of the lung clearance of a well-defined, moderately soluble material was conducted to aid in the development of models used to relate inhalation of radioactive particles to organ doses and bioassay measurements, and in particular to aid in the extrapolation of animal data to man. Lung retention and excretion of 57Co were followed for at least six months after inhalation of monodisperse 0.8 and 1.7 μm diameter cobalt oxide particles by human volunteers, baboons, dogs, guinea-pigs, rats (three strains) and hamsters, and of the 0.8 μm particles by mice. At six months after inhalation of the 0.8 μm particles, lung retention ranged from 1% of the initial lung deposit (ILD) in HMT and Sprague-Dawley rats to 45% ILD in man; and for the 1.7 μm particles from 8% ILD in HMT rats to 56% in man. Supplementary experiments were conducted to determine 57Co excretion patterns following injection of Co(NO3)2 into the blood and following ingestion of cobalt oxide particles, in order to calculate lung clearance rates due to translocation of dissociated 57Co to the blood, S(t), and due to particle transport to the GI tract, M(t). Initially, S(t) for 0.8 μm particles ranged from 0.4% of the contemporary lung content day-1 in humans and baboons to 1.6% day-1 in HMT rats. Initial values for 1.7 μm particles were lower in all species, and ranged from 0.2% in baboons to 0.6% day-1 in HMT rats. Estimated values of M(t) were consistent with the assumption that M(t) is similar for different materials in the same species. In the introductory paper the objectives of the project and methods common to the collaborating laboratories are described, and the results obtained in the various species compared and discussed. Details of the procedures used and of the results obtained at each laboratory are given in Parts II-VIII (J. Aerosol Sci. 20, 189-265, 1989). AU - Bailey, M.R.* AU - Kreyling, W.G. AU - Andre, S.* AU - Batchelor, A.L.* AU - Collier, C.G.* AU - Drosselmeyer, E.* AU - Ferron, G.A. AU - Foster, P.P.* AU - Haider, B. AU - Hodgson, A.* AU - Masse, R.* AU - Métivier, H.J.* AU - Morgan, A.G.* AU - Müller, H.L.* AU - Patrick, G.A.* AU - Pearman, I.* AU - Pickering, S.J.* AU - Ramsden, D.* AU - Stirling, C.M.* AU - Talbot, R.J.* C1 - 42005 C2 - 38208 SP - 169-188 TI - An interspecies comparison of the lung clearance of inhaled monodisperse cobalt oxide particles-Part I: Objectives and summary of results. JO - J. Aerosol Sci. VL - 20 IS - 2 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Erbe, F. AU - Fürst, G.M. AU - Haider, B. AU - Haller, J.* AU - Köhl, B. AU - Kreyling, W.G. AU - Schumann, G. AU - Stocker, M.* AU - Heyder, J. C1 - 42263 C2 - 38203 SP - 1297-1300 TI - A scintillation counter for measuring removal of radioactive particles from dog lungs. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AB - In a recent paper experimental data on total deposition of monodisperse aerosols have been summarized for a wide range of particle sizes and breathing conditions (Heyder et al., J. Aerosol Sci.17, 811–825, 1986). Particle deposition was determined during steady breathing by either evaluating the number of inspired and expired particles per breath with an online technique or by measuring the mean particle concentration in inspired and expired aerosols under equilibrium conditions a certain distance away from the entrance of the respiratory tract. In the present paper the effect of the instrumental dead space on experimental data for total deposition is investigated for both kinds of inhalation apparatus. It turns out that in an online-system the effect of instrumental dead space can be neglected as long as its volume does not exceed 10% of the tidal volume. In an equilibrium concentration system, on the other hand, the instrumental dead space results in a systematic error of total deposition data, which depends on tidal volume and amounts up to 10% for a tidal volume of 500 cm3. AU - Gebhart, J. AU - Schiller-Scotland, C.F. AU - Egan, M.J. AU - Nixon, W. C1 - 17207 C2 - 10245 SP - 141-147 TI - On the relationship between experimental data for total deposition and model calculations - Part I: Effect of instrumental dead space. JO - J. Aerosol Sci. VL - 20 IS - 2 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Gebhart, J. AU - Brand, P. AU - Roth, C. C1 - 33626 C2 - 36578 SP - 1529-1532 TI - A combined DMA-CNC-test-system for commercial laser particle counters. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AB - An interspecies comparison of the lung clearance of a well-defined, moderately soluble material was conducted to aid in the development of models used to relate inhalation of radioactive particles to organ doses and bioassay measurements, and in particular to aid in the extrapolation of animal data to man. Lung retention and excretion of 57Co were followed for at least six months after inhalation of monodisperse 0.8 and 1.7 μm diameter cobalt oxide particles by human volunteers, baboons, dogs, guinea-pigs, rats (three strains) and hamsters, and of the 0.8 μm particles by mice. At six months after inhalation of the 0.8 μm particles, lung retention ranged from 1% of the initial lung deposit (ILD) in HMT and Sprague-Dawley rats to 45% ILD in man; and for the 1.7 μm particles from 8% ILD in HMT rats to 56% in man. Supplementary experiments were conducted to determine 57Co excretion patterns following injection of Co(NO3)2 into the blood and following ingestion of cobalt oxide particles, in order to calculate lung clearance rates due to translocation of dissociated 57Co to the blood, S(t), and due to particle transport to the GI tract, M(t). Initially, S(t) for 0.8 μm particles ranged from 0.4% of the contemporary lung content day−1 in humans and baboons to 1.6% day−1 in HMT rats. Initial values for 1.7 μm particles were lower in all species, and ranged from 0.2% in baboons to 0.6% day−1 in HMT rats. Estimated values of M(t) were consistent with the assumption that M(t) is similar for different materials in the same species. In the introductory paper the objectives of the project and methods common to the collaborating laboratories are described, and the results obtained in the various species compared and discussed. Details of the procedures used and of the results obtained at each laboratory are given in Parts II–VIII. AU - Kreyling, W.G. AU - Ferron, G.A. AU - Haider, B. AU - Bailey, M.R. AU - Andre, S. AU - Batchelor, A. AU - Collier, C.G. AU - Drosselmeyer, E. AU - Foster, P. AU - Hodgson, A. AU - Masse, R. AU - Metivier, H. AU - Morgan, A. AU - Müller, H.-L. AU - Patrick, G. AU - Pearman, I. AU - Pickering, S. AU - Ramsden, D. AU - Stirling, C. AU - Talbot, R.J C1 - 17344 C2 - 10116 SP - 169-188 TI - An Interspecies Comparison of the Lung Clearance of Inhaled Monodisperse Cobalt Oxide Particles. JO - J. Aerosol Sci. VL - 20 IS - 2 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Ferron, G.A. AU - Haider, B. C1 - 41156 C2 - 36521 SP - 219-232 TI - An interspecies comparison of the lung clearance of inhaled monodisperse cobalt oxide particles - Part IV: Lung clearance of inhaled cobalt oxide particles in Beagle dogs. JO - J. Aerosol Sci. VL - 20 IS - 2 PY - 1989 SN - 0021-8502 ER - TY - JOUR AB - An interspecies comparison of the lung clearance of a well-defined inhalable material was conducted to aid in the development of models used to relate inhalation of radioactive particles to organ doses and bioassay measurements, and in particular to aid in the extrapolation of animal data to man. It complements a previous interspecies comparison in which lung clearance of monodisperse, porous 0.8 μm and 1.7 μm diameter cobalt oxide (Co3O4) particles was followed in seven species including man (Bailey et al., J. Aerosol Sci. 20, 169-188, 1989). In the present study baboons, dogs and HMT rats were used since they had shown the most prominent differences in clearance in the previous investigation. Additionally, clearance in the human volunteers and baboons was very similar. The material selected consisted of almost solid, monodisperse 0.9 μm diameter CoP3O4 particles which were chemically similar to the materials studied previously but differed physically with a higher density and a smaller specific surface area. Lung retention and excretion of 57Co were followed for at least six months after inhalation. Lung retention at 6 months after inhalation ranged from 60% of the initial lung deposit in baboons to 5%, in rats and in all three species clearance was considerably slower than that of porous 0.8 μm Co3O4 particles. Lung clearance rates due to translocation of dissociated 57Co to the blood, S(t), and due to particle transport to the GI tract M(t) were calculated. Initially, S(t) ranged from 0.1% of the contemporary lung content day-1 in baboons to 0.7% in rats. Depending on the initial translocation rates of each species, S(t) over time followed patterns expected from a model of particle dissolution derived previously. For each species, a correlation was found between the initial translocation rates and the specific surface area of the three particles used. Estimated values of M(t) were consistent with values obtained previously with other materials. AU - Kreyling, W.G. AU - Andre, S.* AU - Collier, C.G.* AU - Ferron, G.A. AU - Métivier, H.J.* AU - Schumann, G. C1 - 41915 C2 - 0 SP - 1317-1320 TI - Interspecies comparison of lung clearance after inhalation of monodisperse, solid cobalt oxide aerosol particles. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Roth, C. AU - Westenberger, S. C1 - 17580 C2 - 10887 SP - 1289-1292 TI - Production of 111In-Labelled, Monodisperse Polystrene Particles. JO - J. Aerosol Sci. VL - 20 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Roth, C.* AU - Westenberger, S.* AU - Kreyling, W.G. C1 - 41904 C2 - 36506 SP - 1289-1292 TI - Production of 111In-labelled monodisperse aerosol particles. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AB - Polydisperse aerosol size distributions measured with a differential mobility analyser show deviations of the measured size parameters from those parameters of the input distributions. The dependence of the measured modal particle diameters and the geometric standard deviations on the size parameters of log-normal input distributions is derived and the results are proved experimentally by means of fluorescein particles and electron-microscopy. AU - Roth, C. AU - Berlauer, U. AU - Heyder, J.* C1 - 42141 C2 - 10490 SP - 547-556 TI - Particle size analysis of log-normally distributed ultrafine particles using a differential mobility analyser. JO - J. Aerosol Sci. VL - 20 IS - 5 PY - 1989 SN - 0021-8502 ER - TY - JOUR AB - An inhalation device was built up to generate and measure small aerosol boluses for inhalation studies in humans. With a computer controlled magneto-pneumatic valve system an aerosol bolus with a half width of 15 cm3 can be produced and injected in any preselected volume of the breathing cycle at a constant flow rate of 250 cm3/s. AU - Scheuch, G. AU - Gebhart, J. AU - Heigwer, G. AU - Stahlhofen, W. C1 - 17577 C2 - 10884 SP - 1293–1296 TI - A new Device for Human Inhalation Studies with very small Aerosol Boluses. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Schiller-Scotland, C.F.* AU - Gebhart, J. AU - Lintl, H. AU - Siekmeier, R. AU - Kronenberger, H.* C1 - 41913 C2 - 36497 SP - 1305-1308 TI - Human airway diameters derived from aerosol inhalation studies: Reactions of non-smokers and smokers to bronchodilators. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Tschiersch, J. AU - Hietel, B. AU - Schramel, P. C1 - 18558 C2 - 11152 SP - 1181-1184 TI - Wet Deposition of Aerosol: Test of the Method. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Tschiersch, J. AU - Hietel, B. AU - Schramel, P. C1 - 41905 C2 - 36505 SP - 1181-1184 TI - Wet deposition of aerosol: Test of the method. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Tuch, T.H. AU - Brand, P. AU - Ferron, G.A. AU - Karg, E.W. AU - Kreyling, W.G. AU - Leuschel, L. AU - Maier, K.L. AU - Heyder, J. C1 - 42142 C2 - 10970 SP - 1277-1280 TI - Properties of a sodiumbisulfite aerosol. JO - J. Aerosol Sci. VL - 20 IS - 8 PY - 1989 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Gebhart, J.* C1 - 41134 C2 - 36174 SP - 1083-1086 TI - Estimation of the lung deposition of aerosol particles produced with medical nebulizers. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AB - The growth of single dry salt aerosol particles during respiration in human airways is calculated with equations for the mass and heat transport to the particle surface (Ferron, J. Aerosol Sci. 8, 251, 1977) and with axial profiles for the temperature (T) and relative humidity (RH) of the air in the human respiratory tract as derived in a previous study (Ferron et al., J. Aerosol Sci. 19, 343, 1988). The calculations are performed for single dry NaCl, CoCl2.6H2O and ZnSO4.7H2O particles representing salts with large, medium and small increases of particle size in nearly saturated air. The growth of a salt particle is a function of the initial dry particle size, the molecular weight of the salt, its density, and its dissociation constant. It is affected by the profile of the RH of the air in the upper human respiratory tract. Pure salt particles with initial sizes below 1 μm reach their final size during inhalation, whereas particles with initial sizes larger than 7 μm change their size by less than 20% during inhalation. The growth of a salt particle with initial size below 3 μm is influenced by the inhalation airflow. The influence of the reduced transport of water vapor and heat in the lower bronchial tree simulated by a correction equation has hardly any effect on the growth of salt particles. The deposition of salt particles in the human respiratory tract is calculated with a model published before (Ferron et al., J. Aerosol Sci. 16, 133, 1985a). The model is adapted to calculate the deposition of particles with a changing particle diameter. The calculated total lung deposition is enhanced for particles with initial diameter larger than 0.2 μm and reduced for particles with initial diameter less than 0.15 μm with respect to the deposition of non-growing particles. The largest increase in total deposition is found for 1 μm-sized particles. As a first approximation the values for the regional deposition of growing and non-growing particles differ by the same factor as the total deposition is changed. Particles with an initial dry size between 1 and 7 μm have a deposition probability larger than 70% in the bronchial and pulmonary region. A recommendation to estimate the deposition of hygroscopic aerosol particles is derived. AU - Ferron, G.A. AU - Kreyling, W.G. AU - Haider, B. C1 - 41186 C2 - 36166 SP - 611-631 TI - Inhalation of salt aerosol particles - II. Growth and deposition in the human respiratory tract. JO - J. Aerosol Sci. VL - 19 IS - 5 PY - 1988 SN - 0021-8502 ER - TY - JOUR AB - In order to estimate the growth and deposition of hygroscopic aerosol particles during respiration the relative humidity (RH) of the air in the airways must be known. The RH has been calculated with a transport theory for the heat and water vapour in a tube using a numerical method, Cartesian coordinates, and nasal respiration [Ferron et al., J. Aerosol Sci. (1983) 14, 196; Ferron et al., Bull. math. Biol. (1985) 47, 565]. A similar theory is described here to calculate the transport for cylindrical coordinates, both for nasal and oral respiration. The method has the advantage of a reduced computational time compared with the method used before. Calculations are carried out both for nasal and oral inhalation and exhalation. The values of several parameters of the theory, the thickness of the boundary layer, the additional diffusivity by airflow instabilities, the profiles for the temperature and RH at the airway wall, are chosen to fit experimental data on the mean air temperature and RH in the human airways. Since the experimental data are scattered, maximum and minimum curves for the experimental data are derived. It was found mathematically that the RH of the air is more strongly dependent on the RH at the airway wall and less on its temperature. However due to the large uncertainties of the experimental data on the RH no firm conclusion can be drawn. AU - Ferron, G.A. AU - Haider, B. AU - Kreyling, W.G. C1 - 41622 C2 - 36159 SP - 343-363 TI - Inhalation of salt aerosol particles - i. Estimation of the temperature and relative humidity of the air in the human upper airways. JO - J. Aerosol Sci. VL - 19 IS - 3 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Gebhard, J. AU - Scheuch, G. AU - Gehr, P.* AU - Geiser, M.* AU - Heyder, J. AU - Im Hof, V.* C1 - 42325 C2 - 36176 SP - 1105-1108 TI - Individual aerosol exposure unit for small rodents using photometry. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Heyder, J. C1 - 42727 C2 - 36380 SP - 1063-1065 TI - Examining the human lung with aerosols. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Karg, E.W. AU - Erbe, F. AU - Ferron, G.A. AU - Haider, B. AU - Heyder, J. AU - Kreyling, W.G. AU - Peter, J.E. AU - Tuch, T.H. AU - Witte, W. C1 - 42472 C2 - 36258 SP - 971-973 TI - Facilities for chronic exposure of dogs to sulfite aerosols. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Ferron, G.A. AU - Haider, B. C1 - 17272 C2 - 10142 TI - Part 3: Lung Clearance of inhaled Cobald Oxide Particles in Beagle Dogs. JO - J. Aerosol Sci. PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Neuner, M. AU - Matejkova, E. C1 - 17342 C2 - 10118 SP - 1071–1074 TI - Analysis of Intraphagolysosomal Dissolution of Test Particles in Canine Alveolar Macrophages. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Möller, W. AU - Stahlhofen, W. AU - Roth, C. C1 - 42718 C2 - 38213 SP - 967-970 TI - Preparation of spherical magnetic aerosols for long time clearance and relaxation studies of the human lungs. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Roth, C. AU - Berlauer, U. AU - Heyder, J. C1 - 17561 C2 - 10490 TI - Particle Size Analysis of Log-Normally Distributed Ultrafine Particles using a Differential Mobility Analyser. JO - J. Aerosol Sci. PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Roth, C. AU - Köbrich, R. C1 - 42024 C2 - 36140 SP - 939-942 TI - Production of hollow spheres. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Schiller-Scotland, C.F.* AU - Gebhart, J. AU - Lintl, H. AU - Rudolf, G.* AU - Scheuch, G. AU - Siekmeier, R. C1 - 42187 C2 - 36129 SP - 1067-1070 TI - Human airway diameters derived from aerosol inhalation studies - reproducibility of data. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AU - Stahlhofen, W. AU - Möller, W. C1 - 42724 C2 - 38210 SP - 1087-1091 TI - Description of a biomagnetic method for detection of the behavior of magnetic aerosols in the human lungs. JO - J. Aerosol Sci. VL - 19 IS - 7 PY - 1988 SN - 0021-8502 ER - TY - JOUR AB - By means of the electromagnetic theory response curves of optical particle counters (OPC's) can be calculated which describe the flux of light scattered through the collecting aperture of the instrument as function of the diameter d of a spherical particle. Parameter of such curves is the refractive index m of the particle material. The electromagnetic theory of light scattering on spherical particles yields the rigorous solution of the problem. The mathematical formalism of the Mie-theory, however, hardly allows a physical understanding and interpretation of the results. This can be better done by using two approximations. In the limiting case d less than less than lambda ( lambda : wavelength of light) the particle oscillates like a dipole and light scattering can be expressed by polarizability (volume effect). In the limiting case d greater than greater than lambda light scattering becomes a surface effect and the scattered light can be considered as existing of three components which are due to the physical effects of diffraction, reflection and refraction. AU - Anselm, A.F. AU - Gebhart, J. AU - Heyder, J. C1 - 42073 C2 - 38216 SP - 873-876 TI - Interpretation of response functions of optical particle counters in terms of classical optics. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Soderholm, S.C. C1 - 17335 C2 - 10049 SP - 639-642 TI - Estimation of the Times for Evaporation of Pure Water Droplets and for Stabilization of Salt Solution Particles. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Soderholm, S.C.* C1 - 42576 C2 - 40157 SP - 639-642 TI - Estimation of the evaporation or stabilization times of water droplets. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AB - This study shows that particles are present on the broncho-alveolar epithelium predominantly phagocytized in macrophages which will be cleared eventually by particle transport mechanisms. The transport rate from the lower respiratory tract can be quantitated. But dissolution of particles in the lungs and the metabolic fate of the particles and their radioactive label in blood and in the GI tract have to be taken into account. The decreasing particle transport rate indicates a decreasing fraction of particles on the epithelium caused by an increasing number of particles penetrating the epithelial membrane during time. AU - Kreyling, W.G. AU - Schumann, G. C1 - 41712 C2 - 36233 SP - 749-752 TI - Particle transport from the lower respiratory tract. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AB - Bulk transport and Brownian diffusion alone are not sufficient to explain the fact that tidal fresh air reaches the alveolar membrane. Convective mixing is also involved. However, up to now it is unknown which convective mixing mechanism(s) may contribute to gas transport in the lungs. To study gas dispersion, the bolus technique is a usual means. Gas boli however undergo also Brownian diffusion thus masking the mechanical dispersive motion to be studied. Therefore aerosol boli have proved as a useful tracer for such studies. However, it is uncertain up to which extent the intrinsic motion of the aerosol particles contributes to the dispersion of the bolus. In this paper a method is introduced which aims at estimating this contribution. AU - Ramm, U. AU - Rudolf, G. AU - Heyder, J. AU - Gebhart, J. C1 - 40883 C2 - 40130 SP - 753-756 TI - Studies of gas mixing in the human lung by means of aerosols. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AB - To investigate lung clearance from the human tracheo-bronchial tree, W. Stahlhofen et al. performed experiments in which boluses of radioactively labelled aerosols were administered in small volumetric regions of the lungs. As not expected there was found a large amount of aerosol which was cleared slowly even when the bolus was injected at the very end of inhalation. To obtain more information about the site of deposition of this radioactive material, boluses of monodisperse nonlabelled particles were inspired to determine aerosol recovery after periods of breath-holding. AU - Scheuch, G. AU - Stahlhofen, W. C1 - 41151 C2 - 40126 SP - 725-727 TI - Particle deposition of inhaled aerosol boluses in the upper human airways. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AB - When particles are deposited in the respiratory tract, two distinct phases of clearance from the thorax are usually observed. It is generally assumed that the fast phase, which is completed within about a day, represents mucociliary clearance of particles deposited in the tracheobronchial tree, whereas the slow phase represents clearance of the alveolar deposit. Several mechanisms have been proposed which could cause part of the bolus to reach alveoli: the pathways to some alveoli may be relatively short (asymmetric airway branching); the main flow of inspired air in an airway may be confined to the axis (core flow); and some lobes may fill before others (asynchronous or sequential ventilation). In the experiments which are reported here, the administration technique was altered to increase deposition of the bolus in the conducting airways. In addition, another particle material was applied in order to exclude chemical effects on clearance behavior. AU - Stahlofen, W. AU - Gebhart, J. AU - Rudolf, G. AU - Scheuch, G. AU - Bailey, M.R. C1 - 42462 C2 - 10628 SP - 741-744 TI - Human lung clearance of inhaled radioactively labelled particles in horizontal and vertical position of the inhaling person. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AB - The measurement of the radioactive aerosol size distribution was performed using a low pressure cascade impactor (Berner Impactor, Hauke Inc. ) with 9 stages. One impactor (sited in Vienna) had two additional stages in the Aitken particle range. Thin polyethylene foil was used as collection medium on each impactor stage. Gamma spectrometry with high purity Germanium detectors was made of each foil of collected activity. The integrated activity of each set of impactor foils was in good agreement with filter measurements of the airborne activity of the same time period. Study results are discussed. AU - Tschiersch, J. AU - Georgi, B. C1 - 42496 C2 - 38250 SP - 689-692 TI - Chernobyl fallout size distribution in urban areas. JO - J. Aerosol Sci. VL - 18 IS - 6 PY - 1987 SN - 0021-8502 ER - TY - JOUR AU - Stahlhofen, W. AU - Gebhart, J. AU - Rudolf, G. AU - Scheuch, G. C1 - 41001 C2 - 36118 SP - 333-336 TI - Measurement of lung clearance with pulses of radioactively-labelled aerosols. JO - J. Aerosol Sci. VL - 17 IS - 3 PY - 1986 SN - 0021-8502 ER - TY - JOUR AB - Models for the deposition of aerosol particles in the human respiratory tract have been described in literature. Recently data have become available for the extrathoracic, bronchial and pulmonary deposition (Stahlhofen et al., 1980, 1983, 1984; Heyder, 1984). Here data on the total and regional deposition calculated with different mathematical deposition models are compared with each other and with these experimental data for mouth breathing. The calculated results on total deposition show only small differences for different lung structures, particle deposition equations and computation methods. An exception is the model which ends with alveoli at the nineteenth generation according to the lung structure model of Weibel (1963). The calculated bronchial deposition is much larger than the corresponding experimental data, particularly for particle sizes of less than 2 μm. Several possible explanations of this effect are discussed. AU - Ferron, G.A. AU - Hornik, S.* AU - Kreyling, W.G. AU - Haider, B. C1 - 41447 C2 - 38234 SP - 133-143 TI - Comparison of experimental and calculated data for the total and regional deposition in the human lung. JO - J. Aerosol Sci. VL - 16 IS - 2 PY - 1985 SN - 0021-8502 ER - TY - JOUR AB - Aerosol particles suspended in stationary air within a closed system are subject to diffusional and/or gravitational deposition. In the present study monodisperse droplets in the diameter range between 0.09 and 1.5 μm and with a density of 0.912 g cm -3 were inhaled by a normal subject and the losses of particles in the pulmonary air spaces were determined as a function of the period of breath holding t p. In an analogous way various granular bed filters were filled with aerosol and emptied again after a certain pause t p. For particle diameters d < 0.15 μm, particle losses in the lung and in granular bed filters were found to be a function of the diffusion length (Dt p) 1 2 (D: diffusion coefficient). For particle diameters d > 0.8 μm sedimentation dominates and the removal of particles in the lung (filter) is a function of the sedimentation length vt p (v = settling velocity). The functional relationships found between particle losses, residence time, diffusion coefficient, settling velocity and air-space dimensions agree with the formula given by Landahl (1950). Particles between 0.15 and about 0.8 μm diameter undergo combined diffusional and gravitational deposition. Experimental results obtained for this intermediate range show that an independent superimposition of diffusion and sedimentation overestimates particle deposition; in order to fit the experimental points an interactional term had to be subtracted from the superposition of the two mechanisms as independent effects. AU - Gebhart, J. AU - Heyder, J. C1 - 33058 C2 - 38357 SP - 175-187 TI - Removal of aerosol particles from stationary air within porous media. JO - J. Aerosol Sci. VL - 16 IS - 2 PY - 1985 SN - 0021-8502 ER - TY - JOUR AB - The operation of a vibrating orifice aerosol generator using small orifices may be impaired due to clogging by contaminant particulates. This is drastically minimized by additional filtering of the solution close to the orifice. AU - Kreyling, W.G. AU - Erbe, F. C1 - 33056 C2 - 38354 SP - 261-263 TI - Continuous dispersion of aqueous solutions by a modified vibrating orifice aerosol generator. JO - J. Aerosol Sci. VL - 16 IS - 3 PY - 1985 SN - 0021-8502 ER - TY - JOUR AB - Hygroscopic aerosol particles will grow during respiration depending on their own properties and the local relative humidity (RH). Lung deposition models are used to approximate the local deposition of NaCl aerosol particles for different humidity distributions in the upper human airways. A method has been described by G. A. Ferron et al. , which enables the determination of the local temperature, water vapor concentration and RH of the air in the nasopharynx and upper human airways. The mean RH over an airway cross-section shows a fast increase in the nasal region. It reaches a maximum value of 0. 997 in the trachea. A maximum in the particle size is found caused by the maximum in the RH. Such a maximum is not found for larger particle sizes. Since dry NaCl aerosol particles will not grow at RH less than approximately 0. 75, there is no growth in the nostrils. A delay in growth of 0. 01 sec is found. Three lung deposition models are used in the study reported, and one model is then reapplied to determine the local and total deposition probability of a single NaCl particle during the respiration circle. Refs. AU - Ferron, G.A. AU - Hornik, S. C1 - 41831 C2 - 38480 SP - 209-211 TI - Influence of different humidity profiles on the deposition probability of soluble particles in the human lung. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - After hygroscopic aerosols are inhaled, the particles will grow in the respiratory tract, depending on their physical properties, their water content, the local relative humidity (RH) and the breathing pattern. The RH is determined by both the water vapor concentration and the temperature of the air. Hence the RH is a function of the transport of water vapor and heat, and the airflow conditions in the upper human airways. In order to obtain more information from a theoretical point of view a method of approximating the local RH has been developed and described previously. This method is used to determine conditions, whether supersaturation occurs in the lung or not. Their influence on particle growth is estimated. Based on model calculations, supersaturation of the air in respiratory tract occurs during the inhalation of cold air (less than 10 degree C) and high RH (nearly saturated). The calculated RH is too large compared with experimental data for the inhalation of air with an initial temperature of 23 degree C. So a considerable but unknown reduction of the saturation has to be expected for the inhalation of air with low temperatures. AU - Ferron, G.A. AU - Haider, B. AU - Kreyling, W.G. C1 - 41957 C2 - 38335 SP - 211-215 TI - Conditions for measuring supersaturation in the human lung using aerosols. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - Most of the airborne radon-222 daughters are attached to aerosol particles. An experimental set-up for measuring the radon daughter activity as a function of the aerosol particle size is described. An electrostatic classifier selects particles of a certain size range from the indoor or natural aerosol. An arrangement of a filter and an alpha detector registers the radioactivity of the particles. Simultaneously the aerosol concentration is measured by an aerosol electrometer which is upgraded for two particle concentrations. | Most of the airborne radon-222 daughters are attached to aerosol particles. An experimental set-up for measuring the radon daughter activity as a function of the aerosol particle size is described. An electrostatic classifier selects particles of a certain size range from the indoor or natural aerosol. An arrangement of a filter and an alpha detector registers the radioactivity of the particles. Simultaneously the aerosol concentration is measured by an aerosol electrometer which is upgraded for low particle concentrations. AU - Haider, B. AU - Ishida, J.* C1 - 33008 C2 - 35247 SP - 434-437 TI - The particle size dependent attachment of radon daughters to a carrier aerosol. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - Several mathematical formalisms have been proposed to calculate particle transport onto airway surfaces: the temporally and spatially discrete Findeisen formalism; the temporally discrete and spatially continuous Altshuler formalism; and the temporally and spatially continuous Taulbee-Yu formalism; they are termed primary deposition models. Models adopting these formalisms are termed secondary deposition models. This review concentrates on the discussion of the general concepts of primary models and their numerical verification and on characteristics of secondary models. Current deposition models predict particle deposition in close agreement with current experimental data. AU - Heyder, J. AU - Rudolf, G. C1 - 41269 C2 - 38641 SP - 697-707 TI - Mathematical models of particle deposition in the human respiratory tract. JO - J. Aerosol Sci. VL - 15 IS - 6 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - This aerosol generation system enables the production of monodisperse metal oxide aerosols which can be labeled radioactively. The production method consists of the nebulization of a metal-salt solution into monodisperse droplets by a 'May spinning-top aerosol generator', predrying of the droplets, crystal water extraction out of the salt crystals, thermal degradation up to 1200 degree C into metal oxide particles and subsequent cooling to room temperature. Cobalt oxide aerosols with **5**7Co radioactive labeling have been produced and analyzed extensively. In order to study the influence of the angular air jet on the efficiency, measurements have been carried out in which the ratio of the mass of monodisperse droplets per unit time and liquid feed rate is calculated. The size of the droplets follows the equation of Walton and Prewett. In order to study the stability of the aerosol particles, a standardized long-term dissolution test has been developed. AU - Kreyling, W.G. AU - Ferron, G.A. C1 - 33136 C2 - 35556 SP - 367-371 TI - Production of cobalt oxide aerosols with a modified spinning-top aerosol generator. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - The retention of heavy metal compound aerosols in the respiratory tract affects the risk induced by their potential toxicity. In this study the long-term retention in beagle dogs has been measured up to five years after a single inhalation of a monodisperse cobalt compound aerosol. In eight experiments the particle size and the chemical composition are varied. All inhalation experiments are carried out with two dogs, also one intravenous injection experiment for the determination of the liver retention. Parallel to the retention measurements extensive excretion analyses during the first year are carried out in order to study clearance pathways. Using the results of additional metabolism experiments the cobalt concentration data of feces and urine can be evaluated. AU - Kreyling, W.G. AU - Ferron, G.A. AU - Haider, B. C1 - 41274 C2 - 38644 SP - 229-232 TI - The dependency of the lung retention on cobalt aerosol parameters. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - The deposition model makes use of experimental regional deposition data to determine the filtering efficiencies of respective regions. Since the experimental data used have been obtained at a simple breathing pattern, there is only one possibly erroneous 'model' influencing the results of this evaluation. Moreover, from the efficiencies obtained, conclusions can be drawn about the areas which had served as input to the model. The efficiencies are expressed as semi-empirical functions of the breathing parameters, thus inter- and extrapolating the experimental data. In a second step, these 'generalized' efficiencies are used to re-calculate regional deposition for a wide range of particle sizes and breathing parameters. Given reliable regional deposition input data, this model is believed to yield quite reliable information about particle deposition in the human airways. AU - Rudolf, G. C1 - 41766 C2 - 38476 SP - 195-199 TI - A mathematical model for the deposition of aerosol particles in the human respiratory tract. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1984 SN - 0021-8502 ER - TY - JOUR AB - The human respiratory tract can be divided into an extrathoracic, a bronchial and an alveolar region. Knowledge of the deposition of inhaled aerosol particles in these regions (regional deposition) can be used to estimate the health risk connected with the inhalation of atmospheric pollutants. For the determination of regional deposition, radioactively labeled aerosol particles are inhaled through the mouth, and the deposited particles in the respiratory tract are detected by the radiotracer method as described elsewhere. In this paper, attention is focused on deposition in the extrathoracic region. Particles with aerodynamic diameters smaller than 2 mu m pass the extrathoracic region (pharynx, larynx, and 3 cm of the upper end of the trachea) without being deposited. For larger particles, this region has been shown to be an effective aerosol filter, the efficiency of which increases with the flow rate of the aerosol (impaction). AU - Stahlhofen, W. AU - Gebhart, J. AU - Heyder, J. AU - Scheuch, G. AU - Juraske, P. C1 - 33268 C2 - 38601 SP - 215-217 TI - Particle deposition in extrathoracic airways of healthy subjects and of patients with early stages of laryngeal carcinoma. JO - J. Aerosol Sci. VL - 15 IS - 3 PY - 1983 SN - 0021-8502 ER - TY - JOUR AU - Ferron, G.A. AU - Kreyling, W.G. AU - Haider, B. C1 - 42689 C2 - 38138 SP - 248 TI - Some physical properties of cobalt oxide aerosol used for lung retention studies. JO - J. Aerosol Sci. VL - 11 IS - 3 PY - 1980 SN - 0021-8502 ER - TY - JOUR AU - Gebhart, J. AU - Heigwer, G. AU - Heyder, J. AU - Roth, C. AU - Stahlhofen, W. C1 - 42667 C2 - 38139 SP - 237-238 TI - A new device for aerosol and gas inhalation studies and its application in lung investigations. JO - J. Aerosol Sci. VL - 11 IS - 3 PY - 1980 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Kracke, W. C1 - 42648 C2 - 38141 SP - 249 TI - Analysis of the clearance of an inhaled cobalt oxide test aerosol from a dog. JO - J. Aerosol Sci. VL - 11 IS - 3 PY - 1980 SN - 0021-8502 ER - TY - JOUR AU - Gebhart, J. AU - Heyder, J. C1 - 42702 C2 - 38499 SP - 218-219 TI - Lung tests based on aerosol deposition. JO - J. Aerosol Sci. VL - 10 IS - 2 PY - 1979 SN - 0021-8502 ER - TY - JOUR AU - Haider, B. AU - Collins, L.T. C1 - 42646 C2 - 38825 SP - 219 TI - Studies on local aerosol deposition in the human respiratory tract. JO - J. Aerosol Sci. VL - 10 IS - 2 PY - 1979 SN - 0021-8502 ER - TY - JOUR AU - Heyder, J. AU - Gebhart, J. AU - Rudolf, G. AU - Stuck, B. C1 - 42686 C2 - 38160 SP - 211-212 TI - Evaluation of theoretical and experimental response functions of optical aerosol particle counters. JO - J. Aerosol Sci. VL - 10 IS - 2 PY - 1979 SN - 0021-8502 ER - TY - JOUR AB - The change of the particle size of soluble particles in the human respiratory tract may have a large influence on the particle deposition. This paper describes the experimental growth of NaCI particles in a vertical tube with wetted walls. Comparisons with growth theories are made. AU - Jähnert, B. AU - Ferron, G.A. AU - Jacobi, W. C1 - 42687 C2 - 38159 SP - 198 TI - Dynamic of the growth of watersoluble aerosol particles in water saturated air. JO - J. Aerosol Sci. VL - 10 IS - 2 PY - 1979 SN - 0021-8502 ER - TY - JOUR AU - Kreyling, W.G. AU - Ferron, G.A. AU - Haider, B. AU - Jähnert, B. C1 - 42645 C2 - 0 SP - 220-221 TI - Determination of the retention of test aerosols inhaled by beagle dogs. JO - J. Aerosol Sci. VL - 10 IS - 2 PY - 1979 SN - 0021-8502 ER - TY - JOUR AB - There are considerable discrepancies between published lung deposition data. Therefore, the aerosol groups of GSF at Frankfurt/M and of CNEN at Bologna devoted a two week workshop to the understanding of the reasons for some of these discrepancies. This paper reports on the workshop and describes the intercomparison procedures. For all particle sizes and breathing patterns investigated total deposition values for mouthbreathing evaluated with the methods and techniques used in the two laboratories agree satisfactorily and exhibit an intersubject variability. Electrostatic deposition was found to rise with increasing number of charges carried by the particles and with increasing mean residence time of the aerosols in the respiratory tract. AU - Heyder, J. AU - Gebhart, J. AU - Roth, C. AU - Stahlhofen, W. AU - Stuck, B. AU - Tarroni, G.* AU - DeZaiacomo, T.* AU - Formignani, M.* AU - Melandri, C.* AU - Prodi, V.* C1 - 42673 C2 - 38498 SP - 147-155 TI - Intercomparison of lung deposition data for aerosol particles. JO - J. Aerosol Sci. VL - 9 IS - 2 PY - 1978 SN - 0021-8502 ER - TY - JOUR AB - Two He-Ne-laser photometers were used to measure gravitational deposition of particles carried with laminar air flows through inclined circular tubes. If the magnitude of the projection of the settling velocity of aerosol particles in the direction of the air flow is small compared to the magnitude of the maximum velocity of the laminar air flow (rT sin β/L = ν sin β/u 0 ≪ 1), gravitational deposition for upward and downward flow can be described by DE = 2 π[2κ√(1 - κ 2 3) - κ 1 3 √(1 - κ 2 3) + arc sin κ 1 3], where κ = 3T cos β/4. The problem was applied to a system of randomly oriented circular tubes for which several analytical approximations were derived. AU - Heyder, J. AU - Gebhart, J. C1 - 41104 C2 - 38088 SP - 289-295 TI - Gravitational deposition of particles from laminar aerosol flow through inclined circular tubes. JO - J. Aerosol Sci. VL - 8 IS - 4 PY - 1977 SN - 0021-8502 ER - TY - JOUR AB - An analytical expression for the gravitational deposition of aerosol particles confined in a cylindrical tube of infinite length and inclined to the horizontal is presented. With a computer this deposition probability was calculated for a system of randomly oriented identical tubes which has practical application to particle settling in the human respiratory tract during respiratory pauses. AU - Heyder, J. C1 - 41552 C2 - 37939 SP - 133-137 TI - Gravitational deposition of aerosol particles within a system of randomly oriented tubes. JO - J. Aerosol Sci. VL - 6 IS - 2 PY - 1975 SN - 0021-8502 ER - TY - JOUR AB - A laser aerosol size spectrometer (LASS), an "Owl" and a spiral centrifuge were utilized to measure the distribution of diameters of airborne droplets of di-2-ethylhexyl sebacate (DES). The LASS and the centrifuge were calibrated with polystyrene spheres. When DES aerosols were measured the refractive index and the density of DES were taken into account. The modal diameters evaluated with the optical instruments agree very well; the centrifuge gives slightly lower values. The influence of density, refractive index and aerodynamic drag on the size evaluation is discussed. Aggregates of uniform polystyrene spheres served as irregular shaped particles. In contrast to the centrifuge the LASS measures the equivalent spherical volume diameter independent of the particle shape. AU - Heyder, J. AU - Porstendörfer, J.* C1 - 42708 C2 - 35517 SP - 387-400 TI - Comparison of optical and centrifugal aerosol spectrometry: Liquid and non-spherical particles. JO - J. Aerosol Sci. VL - 5 IS - 4 PY - 1974 SN - 0021-8502 ER - TY - JOUR AB - Filtration properties of glass bead media for aerosol particles in the 0·1-2 μm size range are studied. Monodisperse aerosols of polystyrene spheres are used and concentration measurements in front and behind the filter are carried out with a Laser Aerosol Spectrometer. For the bead sizes investigated (0·4, 0·16, 0·05, 0·0185 cm in dia.) the porosity of the filter is found to be always 38·5 per cent. The mean flow velocity inside the filter changes from about 0·7 to 17 cm sec-1. Within this range a linear relationship between pressure drop and flow velocity is measured and with respect to the bead size the law of Hagen-Poiseuille is valid. The penetration maximum proves to be a function not only of the particle diameter, but also of the flow velocity and the bead size. In the particle size range of predominating diffusion the penetration can be generally expressed by: c co=e- 6.39 D 2 3.L v 2 3.R 5 3 K L-filter length; D-diffusion constant; v-mean flow velocity; RK-bead radius). For bigger particles the coexistence of gravitational and inertial deposition prevents an exact analysis of the experimental results. AU - Gebhart, J. AU - Roth, C. AU - Stahlhofen, W. C1 - 41591 C2 - 35507 SP - 355-371 TI - Filtration properties of glass bead media for aerosol particles in the 0·1-2 μm size range. JO - J. Aerosol Sci. VL - 4 IS - 5 PY - 1973 SN - 0021-8502 ER - TY - JOUR AB - The deposition in the human respiratory tract of monodisperse airborne di-2-ethylhexyl sebacate (DES) droplets in the size range from 0.2 to 1 μm dia, was studied for a 500 cm 3 tidal volume and a 4 sec breathing cycle without respiratory pauses. Four male subjects served as volunteers in the breathing experiments. The calculation of deposition was based upon measurements of the number concentration of the aerosol particles and the respiratory flow rate at the mouth. No particle size of minimum deposition and no differences in the average deposition of the subjects was found provided the inhalations were initiated from the subjects' normal functional residual capacities. The deposition in the above particle size range was found to be about 0.1. AU - Heyder, J. AU - Gebhart, J. AU - Heigwer, G. AU - Roth, C. AU - Stahlhofen, W. C1 - 42533 C2 - 35376 SP - 191-208 TI - Experimental studies of the total deposition of aerosol particles in the human respiratory tract. JO - J. Aerosol Sci. VL - 4 IS - 3 PY - 1973 SN - 0021-8502 ER - TY - JOUR AB - Experiments on the inhalation of 0·5 μm dia. particles are described. For a single inhalation of aerosol the effects of separately varying tidal volume and expiratory reserve volume were studied. The results are consistent with the idea that mechanical mixing within the tidal air and between the tidal and reserve air takes place only in the anatomical dead space of the lungs. Experiments with constant reserve volume on the inhalation of a bolus or slug of aerosol, followed by clean air to complete the tidal inhalation, showed that the depth of penetration of the aerosol into the reserve air was not much less than when aerosol was inhaled for the entire tidal inhalation. This indicates that the first part of tidal air, which penetrates most deeply, is not much affected by the volume subsequently inhaled, the reason being that it is in the alveolated airways where there is no mechanical mixing of air. This supports the 'first in, last out' theory of breathing, subject to some spreading in volume. A compartment theory of the dispersion of particles in the lungs, based on tidal, reserve and residual volumes, enables six transfer coefficients of aerosol particles to be evaluated from wash-in and wash-out experiments. With these coefficients it is possible to predict the behaviour of aerosols during various breathing manoeuvres. The theory is independent of assumptions about the mechanisms of particle exchange. Evaluation of the transfer coefficients would identify differences between subjects and could be of clinical interest. AU - Heyder, J. AU - Davies, C.N.* C1 - 41918 C2 - 37945 SP - 437-452 TI - The breathing of half micron aerosols-III dispersion of particles in the respiratory tract. JO - J. Aerosol Sci. VL - 2 IS - 4 PY - 1971 SN - 0021-8502 ER -