Transplacental transfer of polychlorinated biphenyls and polybrominated diphenyl ethers in arctic beluga whales (Delphinapterus leucas)

This study found that arctic beluga whales (Delphinapterus leucas) transferred, on average, 11.4% (7.5 mg) and 11.1% (0.1 mg) of their polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) blubber burden to their near-term fetuses. A single physicochemical parameter, log K(OW), largely explained this transplacental transfer for PCBs (r(2) =0.79, p < 0.00001) and PBDEs (r(2) = 0.37, p = 0.007), with congeners having a log K(OW) < 6.5 preferentially transferred to the fetus. Blubber concentrations of 257 ng/g lipid weight (lw) PCBs and 3.8 ng/g (lw) PBDEs in beluga fetuses highlights the exposure to endocrine-disrupting compounds during a critical developmental stage. The implications of detecting these levels of legacy PCBs and the flame retardant PBDEs in unborn arctic beluga are unclear.