title: Analysis of a long-term measurement of air pollutants (2007-2011) in North China Plain (NCP); Impact of emission reduction during the Beijing Olympic Games.
abstract: Five years measurements were used to evaluate the effect of emission controls on the changes of air pollutants in Beijing and its surroundings in the NCP during 2008 Olympic Games (2008OG). The major challenge of this study was to filter out the effect of variability of meteorological conditions, when compared the air pollutants during the game to non-game period. We used four-year (2007, 2009-2011) average as the Non-2008OG to smooth the temporal variability caused by meteorological parameters. To study the spatial variability and regional transport, 6 sites (urban, rural, a mega city, a heavy industrial city, and a remote site) were selected. The result showed that the annually meteorological variability was significantly reduced. Such as, in BJ the differences between 2008OG and 5-years averaged values were 2.7% for relative humidity and 0.6% for wind speed. As a result, the anomaly of air pollutants between 2008OG and Non-2008OG can largely attribute to the emission control. The comparison showed that the major pollutants (PM10, PM2.5, NO, NOx) at the 6 sites in 2008OG were consistently lowered. For example, PM2.5 in BJ decreased from 75 to 45 μg/m(3) (40% reduction). However, the emission controls had minor effect on O3 concentrations (1% reduction). In contrast, the O3 precursor (NOx) reduced from 19.7 to 13.2 ppb (33% reduction). The in-sensitivity between NOx and O3 suggested that the O3 formation was under VOCs control condition in NCP, showing that strong VOC emission control is needed in order to significantly reduce O3 concentration in the region.
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG (State Kay Laboratory of Loess and Quaternary Geology), Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ruiguang
authors.initials: R
authors.lastname: Xu
authors.affiliation: The State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Guiqian
authors.initials: G
authors.lastname: Tang
authors.affiliation: The State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. Electronic address: wys@mail.iap.ac.cn.
authors.forename: Yuesi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG (State Kay Laboratory of Loess and Quaternary Geology), Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Urban Atmospheric Environment (CEUAE), Xiamen 361021, China; National Center for Atmospheric Research, Boulder, CO 80303, USA. Electronic address: xxtie@ucar.edu.
authors.forename: Xuexi
authors.initials: X
authors.lastname: Tie
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D000068476:Beijing; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D058735:Environmental Policy; D006801:Humans; D055904:Meteorology; D052638:Particulate Matter / Q000032:analysis; D014919:Wind
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: 2008 Beijing Olympic; Emission control; NCP; PM(2.5), NO(x), and O(3)