Orcas and other dolphins living in European waters are facing a severe threat from lingering toxic chemicals that have been banned for decades,
according to a study led by the Zoological Society of London and published in the journal Scientific Reports. The research, which was based on long-term studies of more than 1,000 biopsied whales, dolphins, and porpoises in European waters, found that the blubber of these cetaceans contain some of the highest concentrations of polychlorinated biphenyls (PCBs) in the world. Without much stronger restrictions, “PCBs will continue to drive population declines or suppress population recovery in Europe for many decades to come,” the study’s authors wrote. PCBs are a group of man-made chemicals previously used in the manufacture of electrical equipment, flame-retardants, and paints.