Concentration of polychlorinated biphenyls and organochlorine pesticides in some edible fish species from the Shadegan Marshes (Iran).

Concentrations of polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and analogs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), were determined in 8 fish species collected during October and November 2007 from the largest Iranian wetland, the Shadegan Marshes. Fishes were selected on the basis of their importance in the local diet and feeding behavior. In all samples, OCPs were found in higher concentrations than PCBs. Common carp (Cyprinus carpio) had the highest OCs (1680 ng/g lipid wt.), with DDTs being most prevalent and p,p'-DDE contributing by 53-88% to the total DDTs. In all samples, OCs were found in order of DDTs>HCHs>PCBs>HCB. The highest concentration of HCHs was found in common carp (410±180 ng/g lipid wt.) and α-HCH was the predominant compound among HCH isomers (range 70-90%, mean 82%) in all species. All samples contained PCBs and CB 28 (37%) and CB 52 (26%) were the most frequently occurring congeners. common barbel (Barbus barbulus) (70±17 ng/g lipid wt.) exhibited the highest concentrations of HCB. OC levels in fish were relatively low, but the levels of several OCs in some of our specimens exceed the guidelines for food safety issued by the European Union (EU) and US Food and Drug Administration (FDA).