de Jesus, A.L.* ; Rahman, M.M.* ; Mazaheri, M.* ; Thompson, H.* ; Knibbs, L.D.* ; Jeong, C.* ; Evans, G.* ; Nei, W.* ; Ding, A.* ; Qiao, L.* ; Li, L.* ; Portin, H.* ; Niemi, J.V.* ; Timonen, H.* ; Luoma, K.* ; Petäjä, T.* ; Kulmala, M.* ; Kowalski, M. ; Peters, A. ; Cyrys, J. ; Ferrero, L.* ; Manigrasso, M.* ; Avino, P.* ; Buonano, G.* ; Reche, C.* ; Querol, X.* ; Beddows, D.* ; Harrison, R.M.* ; Sowlat, M.H.* ; Sioutas, C.* ; Morawska, L.*
Ultrafine particles and PM2.5 in the air of cities around the world: Are they representative of each other?
Environ. Int. 129, 118-135 (2019)
Can mitigating only particle mass, as the existing air quality measures do, ultimately lead to reduction in ultrafine particles (UFP)? The aim of this study was to provide a broader urban perspective on the relationship between UFP, measured in terms of particle number concentration (PNC) and PM2.5 (mass concentration of particles with aerodynamic diameter < 2.5 mu m) and factors that influence their concentrations. Hourly average PNC and PM2.5 were acquired from 10 cities located in North America, Europe, Asia, and Australia over a 12-month period. A pairwise comparison of the mean difference and the Kolmogorov-Smirnov test with the application of bootstrapping were performed for each city. Diurnal and seasonal trends were obtained using a generalized additive model (GAM). The particle number to mass concentration ratios and the Pearson's correlation coefficient were calculated to elucidate the nature of the relationship between these two metrics.Results show that the annual mean concentrations ranged from 8.0 x 10 3 to 19.5 x 10(3) particles.cm(-3) and from 7.0 to 65.8 mu g.m(-3) for PNC and PM2.5, respectively, with the data distributions generally skewed to the right, and with a wider spread for PNC. PNC showed a more distinct diurnal trend compared with PM2.5, attributed to the high contributions of UFP from vehicular emissions to PNC. The variation in both PNC and PM2.5 due to seasonality is linked to the cities' geographical location and features. Clustering the cities based on annual median concentrations of both PNC and PM2.5 demonstrated that a high PNC level does not lead to a high PM2.5, and vice versa. The particle number-to-mass ratio (in units of 10(9) particles.mu g(-1)) ranged from 0.14 to 2.2, > 1 for roadside sites and < 1 for urban background sites with lower values for more polluted cities. The Pearson's r ranged from 0.09 to 0.64 for the log-transformed data, indicating generally poor linear correlation between PNC and PM2.5. Therefore, PNC and PM2.5 measurements are not representative of each other; and regulating PM2.5 does little to reduce PNC. This highlights the need to establish regulatory approaches and control measures to address the impacts of elevated UFP concentrations, especially in urban areas, considering their potential health risks.
Impact Factor
Scopus SNIP
Web of Science
Times Cited
Scopus
Cited By
Altmetric
Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
Urban Aerosol ; Particle Number Concentration ; Pm2.5; Fine Particulate Matter; Aerosol-size Distributions; Number Concentrations; Source Apportionment; Temporal Variations; Chemical-composition; Spatial Variation; Los-angeles; Mass Concentrations; Seasonal-variation
Keywords plus
Sprache
Veröffentlichungsjahr
2019
Prepublished im Jahr
HGF-Berichtsjahr
2019
ISSN (print) / ISBN
0160-4120
e-ISSN
1873-6750
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 129,
Heft: ,
Seiten: 118-135
Artikelnummer: ,
Supplement: ,
Reihe
Verlag
Elsevier
Verlagsort
The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
Tag d. mündl. Prüfung
0000-00-00
Betreuer
Gutachter
Prüfer
Topic
Hochschule
Hochschulort
Fakultät
Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
Institut(e)
Institute of Epidemiology (EPI)
POF Topic(s)
30202 - Environmental Health
Forschungsfeld(er)
Genetics and Epidemiology
PSP-Element(e)
G-504000-004
Förderungen
Copyright
Erfassungsdatum
2019-05-28