PCB levels still high in Europe’s killer whales, smaller dolphins
Decades after ban, toxic pollutants remain a threat to long-lived cetaceans
By Susan Milius
Decades after Europe banned toxic PCBs, the region’s killer whales and three smaller dolphin species still carry high levels of the pollutants.
“They’re still at concentrations we really need to worry about,” said veterinary specialist Paul D. Jepson of the Zoological Society of London at a news conference January 12.
PCBs (polychlorinated biphenyls) were once industrial wonder chemicals but were banned by many developed nations by the end of the 1980s because of human health and environmental concerns. Despite the long gap since then, mean concentration of the chemicals in the blubber of some populations of Europe’s killer whales exceeds — often by a lot — a high threshold for health damage. So do PCB concentrations in bottlenose as well as in striped dolphins, Jepson and his colleagues report online January 14 in Scientific Reports. PCB concentrations in harbor porpoises were lower but still exceeded a lower threshold above which physiological changes may occur.