BaselineOrganochlorine pesticide content and distribution in coastal seafoods in Zhoushan, Zhejiang Province

•OCP accumulation was measured in seafoods from four counties of Zhejiang Province.•OCP concentrations in 13 types of seafoods ranged from 258.3 to 3459.6 ng g−1 (lw).•HCHs and DDTs were the most abundant OCPs in seafoods from the tested environments.•Total OCP content in seafoods varied regionally and was highest in Shengsi and Putuo.•OCPs in seafoods of Shengsi may be from dicofol products used in Yangtze Estuary.

Thirteen types of seafoods were collected from four counties (districts) of Zhoushan, Zhejiang Province, China and analyzed for organochlorine pesticides (OCPs). The average concentrations of OCPs in seafoods ranged from 258.3 ng g−1 (lw) to 3459.6 ng g−1 (lw). Hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were the most abundant compounds in these environments and in total accounted for 8.2-62.2% and 32.1-89.0% of the total OCPs in seafoods, respectively. The total OCP contents were higher in seafoods from Shengsi and Putuo and lower in those from Dinghai and Daishan. The ratios of (DDE + DDD)/DDTs reflected a mixed input of accumulated and fresh DDTs in Shengsi, Putuo. The ratios of o,p′-DDT/p,p′-DDT in seafoods of Shengsi ranged 0.10-0.60 (mean 0.33), indicating that DDTs in seafoods of Shengsi may partly contain dicofol products and other pollutants accumulated in Yangtze Estuary. DDTs are a greater concern for ecotoxicological risk in the study area.