Seasonal variations and chemical characteristics of PM(2.5) in Wuhan, central China.
PM2.5 samples were collected at an urban site (WD) and a suburban site (TH) in Wuhan from August 2012 to July 2013. The mass concentrations of water-soluble inorganic ions, carbonaceous species and elements of PM2.5 were measured. The annual mean concentrations of PM2.5 were 106.5 μg/m(3) and 114.9 μg/m(3) at WD and TH, respectively. The chemical compositions of PM2.5 at WD were similar to those at TH and the fractions of the major components of PM2.5 in Wuhan were in the following order of trace elements<chloride<EC (elemental carbon)<ammonium<nitrate<soil dust<sulfate<OM (organic matter). As the secondary ionic aerosols (SIA) and dominant ions, SO4(2-), NO3(-) and NH4(+) all exhibited strong seasonal distributions, consistently with the lowest values in summer and the highest in winter. OM was the most abundant component in PM2.5, the lowest concentrations of which were observed in summer at both sites, while the highest concentrations of OC (organic carbon) appeared in winter at WD and autumn at TH, respectively. The highest OC concentration observed in autumn was tightly related to the biomass burning near the suburban site. The crustal elements (Mg, K, Ca and Fe) dominated the 20 detected elements in PM2.5, with the highest concentrations in spring in Wuhan, which might be due to frequent sandstorm from north carrying abundant soil dusts in spring in China. Ten trace elements (Cu, Ga, Ag, Tl, Ca, As, Zn, Pb, Se and Cd) were enriched in PM2.5 and the higher EF for Ag, Pb, Se and Cd in PM2.5 indicated that the air pollution from vehicle exhaust emission and coal burning in Wuhan was serious and noteworthy.
Department of Environmental Engineering, School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China.
Fan
F
Zhang
Department of Environmental Engineering, School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China.
Zu-wu
ZW
Wang
Department of Environmental Engineering, School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China. Electronic address: chenghr@whu.edu.cn.
Hai-rong
HR
Cheng
Department of Environmental Engineering, School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China.
Xiao-pu
XP
Lv
State Key Laboratory for Information Engineering in Surveying, Mapping & Remote Sensing, Wuhan University, Wuhan 430079, China.
Wei
W
Gong
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Xin-ming
XM
Wang
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Gan
G
Zhang
D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D002681:China; D004784:Environmental Monitoring; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D014131:Trace Elements / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis
D000393:Air Pollutants; D052638:Particulate Matter; D014131:Trace Elements; D001335:Vehicle Emissions
Chemical characteristics; PM(2.5); Seasonal variations; Wuhan