Abstract:

52 biological samples and 100 soil samples in mountain and plain landforms in Chengdu Economic Region，Sichuan Province were collected at spring and autumn respectively.The US EPA method 8080A was used to analysis concentrations of organochlorine pesticides (OCPs) in soil and organism to investigate pollution states at different landforms and seasons.The results showed that concentrations of DDT in soil were higher than HCH in soil，and the concentrations in Mianzhu (landform is plain) were higher than that in Yanting (mountain area).The seasonal characteristic in Mianzhu was that OCP concentrations of soil collected at autumn were higher than that collected at spring.However，the result was conversely in Yanting，the spring one was higher than that in autumn.The detectable ratios of OCP in plants were very high，whereas the concentrations in plant were below national standards，which existed potential harm to human health.The concentrations of OCP in crops with rich oils were higher than in leafshaped vegetables，higher than in fruitshaped vegetables.Landform，organic matters and pesticides usage were major factors on the difference of seasonal soil OCP concentrations，and absorption styles and physical and chemical properties of OCPs were responsible for different concentrations in organism.

Key words: landform/ season/ Chengdu Economic Region/organochlorine pesticide