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| Titel |
Remarkable dynamics of nanoparticles in the urban atmosphere |
| VerfasserIn |
M. Dall'Osto, A. Thorpe, D. C. S. Beddows, R. M. Harrison, J. F. Barlow, T. Dunbar, P. I. Williams, H. Coe |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 13 ; Nr. 11, no. 13 (2011-07-12), S.6623-6637 |
| Datensatznummer |
250009907
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| Publikation (Nr.) |
 copernicus.org/acp-11-6623-2011.pdf |
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| Zusammenfassung |
| Nanoparticles emitted from road traffic are the largest source of respiratory
exposure for the general public living in urban areas. It has been suggested
that adverse health effects of airborne particles may scale with airborne
particle number, which if correct, focuses attention on the nanoparticle
(less than 100 nm) size range which dominates the number count in
urban areas. Urban measurements of particle size distributions have tended to
show a broadly similar pattern dominated by a mode centred on 20–30 nm
diameter emitted by diesel engine exhaust. In this paper we report
the results of measurements of particle number concentration and size
distribution made in a major London park as well as on the BT Tower, 160 m
aloft. These measurements taken during the REPARTEE project (Regents
Park and BT Tower experiment) show a remarkable shift in particle size
distributions with major losses of the smallest particle class as particles
are advected away from the traffic source. In the Park, the traffic related
mode at 20–30 nm diameter is much reduced with a new mode at <10 nm. Size
distribution measurements also revealed higher number concentrations of
sub-50 nm particles at the BT Tower during days affected by higher turbulence
as determined by Doppler Lidar measurements and are indicative of loss of
nanoparticles from air aged during less turbulent conditions. These results
are suggestive of nanoparticle loss by evaporation, rather than coagulation
processes. The results have major implications for understanding the impacts
of traffic-generated particulate matter on human health. |
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