The levels and distribution of organochlorine pesticides (OCPs) in sediments from the Haihe River, China

The levels and distribution patterns of the selected organochlorine pesticides (OCPs = p,p′-DDT, o,p′-DDT, p,p′-DDE, p,p′-DDD, α-, β-, γ- and δ-HCH) in surficial sediments from the Haihe River and Dagu Drainage River of Tianjin were investigated by means of gas chromatography coupled with micro-electronic capture detector (GC-μECD). Concentrations of OCPs in the sediments from the Haihe River ranged from 1.88 to 18.76 ng g−1 (mean 7.33 ng g−1) for ∑HCH, 0.32-80.18 ng g−1 (mean 15.94 ng g−1) for ∑DDT. Compared with the Haihe River, the Dagu Drainage River was much more contaminated by HCHs and DDTs, wherein ∑HCH ranged from 33.24 to 141.03 ng g−1 (mean 87.74 ng g−1) and ∑DDT ranged from 3.60 to 83.49 ng g−1 with a mean value of 35.52 ng g−1. The concentration distribution of ∑DDT and ∑HCH was different indicated their different contamination sources. Composition analyses indicated that a recent usage or discharge of HCH and DDT into the Dagu Drainage River.