[Levels and distribution of organochlorine pesticides and dioxin-like polychlorinated biphenyls in atmospheric particulates in Xining and Tianjun, Qinghai province, China].

The levels of OCPs and DL-PCBs in the atmospheric particulates of Xining city and Tianjun county in Qinghai province were determined. DDTs and HCHs were the main component of OCPs in the atmospheric particulates. The average levels of DDTs and HCHs in the atmospheric particulates of Xining city were 35 pg x m(-3) and 5.9 pg x m(-3) in summer and 93 pg x m(-3) and 11 pg x m(-3) in winter, respectively. In Tianjun county, they were 83 pg x m(-3) and 6.4 pg x m(-3) in summer and 28 pg x m(-3) and 6.7 pg x m(-3) in winter, respectively. Compared with other Asian areas, the average levels of them in Qinghai province were lower. Meanwhile, the average levels of DL-PCBs in Xining city were 0.52 pg x m(-3) in summer and 0.99 pg x m(-3) in winter, respectively, and in Tianjun county were 0.58 pg x m(-3) in summer and 0.52 pg x m(-3) in winter, respectively. The average levels of OCPs in summer and winter of Xining city were higher than those in Tianjun county, but the average levels of DL-PCBs in two cities were similar. Compared with the polar region, the distribution principles of DL-PCBs in the plateau area were certainly similar, while HCHs and DDTs were different.