Presence and Distribution of Polychlorinated Biphenyls (PCB) in Arctic and Subarctic Marine Food Chains

Abstract

Polychlorinated biphenyls (PCB), man-made industrial chemicals, have been identified in tissues of polar bears (Ursus maritimus), ringed (Phoca hispida) and square flipper (Erignathus barbatus) seals, and Arctic char (Salvelinus alpinus) of the Canadian arctic and subarctic. All tissues from each species examined contained these compounds. PCB content in tissue, both absolute and relative to the concentration of DDT (p,p′-DDE + p,p′-DDD + p,p′-DDT), generally increased from seals to adult polar bears to polar bear cubs and young. Polar bear milk contained high concentrations of PCB and is the most probable source of the high concentrations in polar bear cubs. Chromatograms revealed a greater accumulation of higher chlorinated PCB isomers in polar bears than in seals, their main food. Residue data suggest that polar bear subpopulations in the eastern Canadian arctic and subarctic have been exposed to higher levels of PCB and DDT than western subpopulations.