Levels of C_(10)-C_(13) Polychloro-n-Alkanes in Marine Mammals from the Arctic and the St. Lawrence River Estuary

摘要

Marine mammals from various regions of the Arctic and the St. Lawrence River estuary were examined for the first time for levels of C_(10)-C_(13) polychloro-n-alkanes (sPCAs). Respective mean total sPCA concentrations in the blubber of beluga whales (Delphinapterus leucas) from Saqqaq and Nuussuaq, western Greenland, were 0.23±0.02 (n=2) and 0.164±0.06 μg/g (n=2), sirnilar to that in beluga from the Mackenzie Delta in the western Canadian Arctic 0.21±0.08 μg/g (n=3). sPCAs levels were higher in beluga blubber from the St. Lawrence River (0.37 to 1.4 μg/g). Mean sPCA concentrations in the blubber samples from walruses (Odobenus rosmarus) (Thule, northwest Greenland) and ringed seal (Phoca hispida) (Eureka, southwest Ellesmere Island) were 0.43±0.06 (n=2) and 0.53±0.2 μg/g (n=6), respectively. Relative to commercial sPCA formulations, samples from the Arctic marine mammals showed a predominance of the shorter chain length lower percent chlorinated PCA congeners, the more volatile components of industrial formulations. This observation is consistent with long-range atmospheric transport of sPCAs to this region. The profiles of the belugas from the St. Lawrence River estuary, however, had higher proportions of the less volatile sPCA congeners, implying that contamination to this region is probably from local sources.