Polychlorinated Biphenyls and Hydroxylated Polychlorinated Biphenyls in Plasma of Bottlenose Dolphins (Tursiops truncatus) from the Western Atlantic and the Gulf of Mexico

Polychlorinated biphenyls (PCBs) and hydroxylated metabolic products (OH-PCBs) were measured in plasma collected from live-captured and released bottlenose dolphins (Tursiops truncatus) from five different locations in the Western Atlantic and the Gulf of Mexico in 2003 and 2004. In 2004, the sum (Σ) of concentration of PCBs in plasma of dolphins sampled off Charleston, SC [geometric mean:  223 ng/g of wet weight (w.w.)] was significantly higher (p<0.05) than concentrations detected in animals from the Indian River Lagoon, FL (ΣPCBs:  122 ng/g w.w.) and the Sarasota Bay, FL (ΣPCBs:  111 ng/g w.w.). The PCB homolog profiles were similar among locations. Concentrations of OH-PCBs were significantly higher (p<0.05) in plasma of dolphins from Charleston, SC (ΣOH-PCBs for 2003:  126 ng/g w.w.; 2004:  138 ng/g w.w.) than animals from Florida (ΣOH-PCBs ranged from 6 to 47 ng/g w.w.) and Bermuda (8.3 ng/g w.w.); however, concentrations in the Charleston samples did not differ from animals captured in Delaware Bay, NJ (57 ng/g w.w.). The ΣOH-PCBs constituted 2−68% of the total PCB concentrations in plasma. Dichloro- to nonachloro-OH-PCBs were quantified using high-resolution gas chromatography mass spectrometry, but only around 20% of OH-PCBs could be identified by comparison to authentic standards. Results from this study show that OH-PCB are important environmental contaminants in dolphins and suggest that PCBs, decades after their ban, may still constitute a threat to wildlife.