Concentrations and composition of organochlorine pesticides in surface sediments from Hong Lake

Surface sediments of Hong Lake were divided into upper(0～2cm) and lower part(2～10cm) through sampling process.Concentrations of organochlorine pesticides(OCPs) in the sediments were determined using GC-ECD, and their distribution, composition and source were discussed.HCHs concentration in the upper and lower part sediments were 2.05～19.0ng/g and 0.66～11.3ng/g, respectively.DDTs concentration were 2.39～25.8ng/g and 1.22～27.5ng/g, respectively.Concentrations of OCPs in the lower part were less than those in the upper, which might be some of OCPs in the lower part transported upward.Concentrations of HCHs and DDTs in the sediments were higher in the mouth of a river flowing into the lake, and they were lower near Yangtze River.The concentration trend of HCHs and DDTs showed that they were mainly derived from the river input, industrial and agricultural pollution of Honghu City.Their compositional characteristics indicated that HCHs mainly originated from the application of Lindane, and DDTs mainly from aged environmental residue.