[Distribution of organochlorine pesticides in soils in Haihe River and Haihe Estuary area, China].

Levels and distribution of organochlorine pesticides (OCPs) were investigated in soils along Haihe River and in Haihe Estuary area. 31 surface soil samples were collected on August 2007, and they were extracted using accelerated solvent extraction. The HCHs and DDTs contents in soils were determined by gas chromatography with an electron capture detector (GC-ECD). The results show that the concentrations in soils range from n.d. to 1,728 microg x kg(-1) with a mean value of 93.9 microg x kg(-1) for HCH congeners, and from n.d. to 288 microg x kg(-1) with a mean value of 34.4 microg x kg(-1) for the sum of p,p'-DDT, o,p'-DDT, DDE, and DDD, respectively. The HCHs is dominant, accounting for 72 percent of total OCPs content. The working hypothesis is that OCPs levels and distribution in the area are dependent on the degree of anthropogenic intervention. Higher concentrations of total OCPs are found in the chemical industrial region, and ones from Haihe River area are higher than Haihe Estuary area, due to impact from chemical industrial emissions. According to the isomers of HCHs and metabolites of DDTs, HCHs and DDTs in soils in this area may be derived from the use of pesticide in agricultural and industrial emissions in history, though having recent inputs of OCPs at a few sites. Compared with those in other national or international regions, the concentrations of HCHs and DDTs in soils from Haihe River area are higher. It can be concluded that soil OCPs levels are relatively high in this area.