Levels, seasonal variations and sources of organochlorine pesticides in ambient air of Guangzhou, China

摘要

Air samples were collected at an urban site and a suburban site of Guangzhou city, China, from April 2005 to March 2006, to measure concentrations of organochlorine pesticides (OCPs) in the ambient air and study their seasonal variations and sources. The average concentrations of ∑HCHs, ∑chlordane and ∑DDTs in the air were 93, 287 and 351 pg m~(-3) at the urban site, and 94, 2258 and 399pg m~(-3) at the suburban site, respectively. OCPs in the air were predominantly in gas phase in this study but their concentrations in particle phase were still not neglectable. The air concentrations and seasonal variations of ∑HCHs and ∑DDTs at the urban and suburban sites were similar without obvious difference. The seasonal variations of ∑chlordane concentrations were extremely different at the two sampling sites and the air concentrations were unusually high at suburban site, especially in April and May 2005. The potential sources of HCHs in the air of Guangzhou might come from lindane due to the relative low α-HCH/γ-HCH ratios. Technical chlordane was likely used, especially at or near the suburban site, because the t-chlordane/c-chlordane ratios were > 1.2 and the air concentrations of chlordane were extremely high. Present usage of dicofol at or near Pearl River Delta (PRD) region was implied by the much higher ratios of DDT/(DDE + DDD) and o,p'-DDT/p,p'-DDT. The air concentrations of aldrich were low, and dieldrin and endrin were detected in none of the samples.