Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in beluga whale (Delphinapterus leucas) and ringed seal (Phoca hispida) from the eastern Canadian Arctic

Blubber collected from beluga whales and ringed seals during subsistence hunts in the southern Baffin Island region of the Canadian Arctic were analysed for polychlorinated naphthalenes and eight planar PCB congeners (mono-ortho PCBs: 105, 114, 118 and 156; non-ortho PCBs: 77, 81, 126, 169). SigmaPCN (3-7 Cl) concentrations in blubber ranged from 35.9-383 pg/g (lipid weight; lw) in beluga and 35.4-71.3 pg/g (lw) in ringed seal. These represent the first measurements of PCNs in marine mammals in the Canadian Arctic, mammals which are an important part of the traditional diet of the indigenous population. SigmaCoplPCB concentrations were much higher, ranging from 15.5-317 ng/g (lw) in beluga whale blubber and 16.5-40.9 ng/g (lw) in ringed seal blubber. PCNs and coplanar PCBs both exhibit dioxin-like toxicity. Although average sigmaPCN concentrations were less than 1% of sigmaCoplPCBs, PCNs contribute up to 11% of TEQ relative to the coplanar PCBs based on TEFs determined by H4IIE enzyme assays.