Distribution Characteristics of Organochlorine Pesticides in Top Soils from Parks in Guangzhou City

Samples of top soils from typical public parks in Guangzhou City in winter and summer seasons were collected and analyzed for organochlorine pesticides (OCPs). Comparison with residue levels in the other parts of Pearl River Delta area, the discussion was made to evaluate the characteristics of temporal and spatial distribution patterns and potential health risk of OCPs in the soils to the human. The hexachlorocyclohexane (HCHs) concentration in the soils in winter and summer seasons ranged from 0.29 to 6.26 ng/g and 0.60 to 8.07 ng/g, averaging 2.06 and 2.44 ng/g,respectively. Dichorodiphenyltricyloroechane (DDTs) concentrations were in the range of 3.27～38.8 ng/g and 1.46～35.5 ng/g, with average values of 12.4 and 12.5 ng/g, respectively. Both HCHs and DDTs do not exceed the LevelⅠ(natural background level) of the National Soil Quality Criteria. The observed low α-HCH/γ-HCH ratios and the general phenomena of γ-HCH>β-HCH in these soil samples may be attributed to recent use of lindane. Higher concentrations of DDTs were found in old parks or within the old town of Guangzhou City, whereas DDT levels were lower in the new parks which located in unpopulated areas.