Studies on Residues of Organochloride Pesticides in the Soils of Hunan Province

120 samples were collected from Hunan Province in May 2004.The samples were analyzed for Hexachlorobenzene(HCB),DDTs(DDT,DDE and DDD),Chlordane, Aldrin,Dieldrin,Endrin,Heptachlor and Mire by AES extraction technique and GC-MS method.The results were as follows: the relevance ratio of HCB and DDTs was 100%,the relevance ratio of Chlordane and Mirex was lower,and Aldrin,Dieldrin,Endrin and Heptachlor were not detected.It was shown that HCB and DDTs were used widely in Hunan.The mass fraction average of OCPs was 115.3(μg/kg),in which DDTs was the primary compound in soil samples,accounting for 96.44% of OCPs. Among the 120 sampling sites,21.67% soil samples have the ratio of(w(DDT))/(w(DDE+DDD)) greater than 1,and it show that there were still fresh DDTs emitted into Hunan soils.Different functions of soil have different levels of OCPs residue, with the residue in dry land higher than that in rice paddy land,the residue in pepper field highest among vegetable fields,and tea field having lowest residue.