Historical records of organochlorine pesticides in a sediment core from the Huaihe River, China

The historical records of organochlorine pesticides (OCPs) in a sediment core are essential for understanding the circulation of them in the global context. In this study, we measured the concentrations of 22 OCPs in the sediment core from the Huaihe River, China by gas chromatography mass spectrometry (GC-MS). The total concentration of 18 kinds of 22 OCPs in the sediment core were in the range of 0.01-7.18 ng g(-1) with an average concentration of 4.53 ng g(-1). The average detection rate was up to 51.60%. Dichlorodiphenyltrichloroethanes (DDTs) were the predominant species in the sediment core. The different categories of OCPs were in the following order: DDTs > hexachlorocyclohexane (HCHs) > Chlordanes > Endosulfans > hexachlorobenzene (HCB). Drins were all lower than detection limits. The temporal trends of OCPs were influenced by their different historical usages, different properties or different degradation conditions in the environment. There was an obvious decreasing trend for OCPs in the core in recent years. The findings suggested there was also no new pollution source input in recent years and OCPs could not cause adverse biological risk in the environment.