SELECTIVE ACCUMULATION OF POLYCHLOROCAMPHENES IN AQUATIC BIOTA FROM THE CANADIAN ARCTIC

Polychlorocamphenes (PCCs; e.g., toxaphene) are major organochlorine contaminants in fish, marine mammals, and other aquatic life from the Arctic. Because PCCs yield complex GC patterns that are often greatly altered in environmental samples compared to a toxaphene standard, identification by GC with electron-capture detection is problematic. We examined PCC profiles in the blubber of narwhal (Monodon monoceros) and the liver of freshwater burbot (Lota lota) from the Canadian Arctic by GC-negative ion mass spectrometry (GC-NIMS). Chromatograms of these specimens showed that certain PCCs were greatly enriched, compared to a toxaphene standard. Mass spectra of accumulated PCCs were consistent with octachloro- and nonachlorobornanes, with possible contribution from chlorinated bornenes. Corresponding GC peaks in the toxaphene standard appeared to be mixtures of seven- and eight-chlorine or eight- and nine-chlorine PCCs. The same peaks in biological samples showed selective accumulation of the more highly chlorinated components. To properly characterize the levels and biological effects of PCCs in arctic food chains will require isolation or synthesis of pure PCC congeners and an evaluation of their physicochemical and toxicological properties.