Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and organochlorine pesticides in yellow-blotched map turtle from the Pascagoula River basin, Mississippi, USA

Concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), -biphenyls (PCBs), and organochlorine pesticides were measured in tissues of map turtles collected from two locations in the Pascagoula Rive r drainage of Mississippi, USA. PCBs were most predominant among the organo chlorines with a concentration of up to 99 ng/g, wet weight (580 ng/g, lipi d weight) in livers. The greatest concentration of PCDDs/DFs of 1.1 pg/g, w et weight (15.76 pg/g, lipid weight) was found in the liver of a male turtl e. The measured concentrations of organochlorines were less than those repo rted for turtles from the Great Lakes Basin and upper St. Lawrence River. P CBs contributed 90-99% of the total estimated 2,3,7,8-tetrachlorodibenzo-p- dioxin equivalents (TEQs). Particularly, PCB congeners 105, 118, and 156 ac counted for 68-80% of the estimated toxic potency of PCBs in turtles.