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| Titel |
Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact |
| VerfasserIn |
T. Wang, W. Nie, J. Gao, L. K. Xue, X. M. Gao, X. F. Wang, J. Qiu, C. N. Poon, S. Meinardi, D. Blake, S. L. Wang, A. J. Ding, F. H. Chai, Q. Z. Zhang, W. X. Wang |
| 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 ; 10, no. 16 ; Nr. 10, no. 16 (2010-08-16), S.7603-7615 |
| Datensatznummer |
250008707
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| Publikation (Nr.) |
 copernicus.org/acp-10-7603-2010.pdf |
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| Zusammenfassung |
| This paper presents the first results of the measurements of trace gases and
aerosols at three surface sites in and outside Beijing before and during the
2008 Olympics. The official air pollution index near the Olympic Stadium and
the data from our nearby site revealed an obvious association between air
quality and meteorology and different responses of secondary and primary
pollutants to the control measures. Ambient concentrations of
vehicle-related nitrogen oxides (NOx) and volatile organic compounds
(VOCs) at an urban site dropped by 25% and 20–45% in the first two
weeks after full control was put in place, but the levels of ozone, sulfate
and nitrate in PM2.5 increased by 16%, 64%, 37%, respectively,
compared to the period prior to the full control; wind data and back
trajectories indicated the contribution of regional pollution from the North
China Plain. Air quality (for both primary and secondary pollutants)
improved significantly during the Games, which were also associated with the
changes in weather conditions (prolonged rainfall, decreased temperature,
and more frequent air masses from clean regions). A comparison of the ozone
data at three sites on eight ozone-pollution days, when the air masses were
from the southeast-south-southwest sector, showed that regional pollution
sources contributed >34–88% to the peak ozone concentrations at the
urban site in Beijing. Regional sources also contributed significantly to
the CO concentrations in urban Beijing. Ozone production efficiencies at two
sites were low (~3 ppbv/ppbv), indicating that ozone formation was
being controlled by VOCs. Compared with data collected in 2005 at a downwind
site, the concentrations of ozone, sulfur dioxide (SO2), total sulfur
(SO2+PM2.5 sulfate), carbon monoxide (CO), reactive aromatics
(toluene and xylenes) sharply decreased (by 8–64%) in 2008, but no
significant changes were observed for the concentrations of PM2.5, fine
sulfate, total odd reactive nitrogen (NOy), and longer lived alkanes
and benzene. We suggest that these results indicate the success of the
government's efforts in reducing emissions of SO2, CO, and VOCs in
Beijing, but increased regional emissions during 2005–2008. More stringent
control of regional emissions will be needed for significant reductions of
ozone and fine particulate pollution in Beijing. |
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