Evaluating the effectiveness of pollution control measures via the occurrence of DDTs and HCHs in wet deposition of an urban center, China.
Wet deposition is not only a mechanism for removing atmospheric pollutants, but also a process which reflects loadings of atmospheric pollutants. Our previous study on wet deposition examined the effectiveness of short-term control measures on atmospheric particulate pollution, which were partly effective for organic pollutants of current input sources. In the present study, dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs), representative of legacy contaminants, were measured in the same samples collected throughout the entire year of 2010 in Guangzhou, a large urban center in South China. Concentrations of ∑DDT (sum of o,p' and p,p'-DDT, o,p' and p,p'-DDE, o,p' and p,p'-DDD, and p,p'-DDMU) and ∑HCH (sum of α-, β-, γ-, and δ-HCH) in wet deposition were in the ranges of nd-69 (average: 1.8 ng L-1) and nd-150 ng L-1(average: 5.1 ng L-1), respectively. In addition, the results of source diagnostics and backward air mass trajectories appeared to suggest the transport of antifouling paint derived DDTs from the coastal region off South China to Guangzhou. The combined wet and dry deposition flux of ∑HCH in the first quarter (January to March) was greater than that in the fourth quarter (October to December), while those of ∑DDT were comparable in the first and fourth quarters. Similar trends were also observed for the concentrations of ∑HCH and ∑DDT in aerosol samples. These results suggested the short-term pollution control measures implemented during the 16th Asian Games and 10th Asian Para Games (held in November and December 2010, respectively) did not work well for DDTs. The reduced input of HCHs during the fourth quarter was probably associated with the strict ban on lindane for food safety, which also exposed the weakness of control measures focusing mainly on the removal of atmospheric particulate matter.
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Ling-Chuan
LC
Guo
School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China. Electronic address: baolianjun@jnu.edu.cn.
Lian-Jun
LJ
Bao
Air Quality Research Division, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada.
Shao-Meng
SM
Li
Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
Shu
S
Tao
School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
Eddy Y
EY
Zeng
D002681:China; D003634:DDT / Q000032:analysis*; D003633:Dichlorodiphenyl Dichloroethylene; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation; D001556:Hexachlorocyclohexane / Q000032:analysis*; D052638:Particulate Matter; D010573:Pesticide Residues / Q000032:analysis*
D052638:Particulate Matter; D010573:Pesticide Residues; D003633:Dichlorodiphenyl Dichloroethylene; D001556:Hexachlorocyclohexane; D003634:DDT
Anthropogenic control; DDTs; HCHs; Urbanized districts; Wet deposition