Residues and Distribution Characters of Organochlorine Pestcides in Vegetable Soil in the Northeast of Hunan

Soil samples of vegetable soil were collected from seven sites in northeast of Hunan province in March 2006. Twenty kinds of organochlorine pesticides in the samples were analyzed with gas chromatography method. HCHs and DDTs were found widely in all these considered samples and with a range of 0.15~16.80 μg·kg-1 for HCHs and 6.05～57.91 μg·kg-1 for DDTs, respectively. The DDTs were the main components in residues of organochlorine pesticides, accounting for more than 70% of the total. The ratio of α-HCH/γ-HCH were above 1.0, DDT /(DDE+DDD) were less than 1.0 in the main parts of regions, indicating that Lindane and DDTs might come from the old usage, but there might be input into environment recently in Yueyang and Hengyang regions. Aldrin, dieldrin, γ-chlordane and heptachlor epoxide were detected with different degree in all the samples. Compared to the reference data, the residual levels of DDTs, HCHs in soil were slighter.