Persistent organochlorine pollutants in different bivalve species from central Vietnamese coasts: Concentrations, profiles, and biota-sediment accumulation factors.

Concentrations of typical persistent organochlorine pollutants (POCPs) like organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in five bivalve species collected from central Vietnamese coasts were determined to provide insights into spatial distribution and bioaccumulation characteristics of these substances. Concentrations of pollutants decreased in the order: PCBs (median 14.6; range 1.39-74.1), dichlorodiphenyltrichloroethane and its metabolites DDTs (2.92; 0.282-70.7), hexachlorocyclohexanes HCHs (2.46; 0.081-30.1), and endosulfan compounds ENDs (1.67; 0.041-36.6) ng/g wet weight. Considerable levels of legacy POCPs in the biota are likely attributed to illegal and/or unintentional sources. Concentrations and accumulation profiles of POCPs in biota samples were affected by species- and site-specific factors. The biota-sediment accumulation factors predicted enrichment potentials of OCPs (notably ENDs and DDTs) from sediment to biota in some certain areas.