Organochlorine pesticides in particulate matter of Beijing, China.

Eighteen organochlorine pesticides (OCPs) in air particulate matter (PM) samples collected from 20 sites in Beijing, China in 2005 and 2006 were analyzed to determine the composition, spatial distribution and sources. Total OCPs of PM2.5 and PM10 ranged from 32.59 pg m(-3) to 9232.31 pg m(-3) and 80.96 pg m(-3) to 9434.97 pg m(-3), respectively, categorized as heavier pollution compared to other cities of China. Among six kinds of functional zones involved, commercial areas and industrial centers were heavily polluted. Distinct concentrations variations were detected in PM with different particle diameters. Pollution distribution was spatially heterogeneous inside the city. The most heavily polluted sites located in the southeast part of the city, where laid many chemical factories. Compositional analysis and principal component analysis (PCA) suggested that past usage of OCPs was the main source, though there were new inputs in some sites.