Sources and Risk Assessment of Organochlorine Pesticides in Surface Soils from the Nature Reserve of the Yellow River Delta, China

Organochlorine pesticides (OCPs) are a group of persistent organic pollutants (POPs). The environmental risk assessment of OCPs in soils is essential for decision-makers to implement applicable measures. Here, we measured the concentrations of OCPs in 26 surface soil samples from the nature reserve of the Yellow River Delta; using soxhlet extraction followed by the gas chromatography (GC) coupled mass spectrometry. Total OCPs concentrations vary widely from 0.01 to 10.5 ng g(-1), with a mean value of 1.68 ng g(-1). The total OCPs in studied soil samples are relatively lower as compared with soil from other regions. Dichlorodiphenyltrichloroethanes (DDTs; including DDT and DDT metabolites) are the predominant species in the studied soils. Source analyses indicated that OCPs in soils mainly originated from historical usage. The significant correlations between all OCPs components suggest that they probably derived from common sources. The risk assessment indicates that hexachlorocyclohexane (HCH) and DDT compounds pose negligible to low adverse effects to human health, whereas carcinogenic risks probability increases when total OCPs are taken into account.