The main article was carried in Nature:

http://www.nature.com/articles/srep18573

‘Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well established does – dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n= 929) or biopsied (n-152) cetaceans, three out of four species, striped dolphins, bottlenose dolphins and killer whales had mean PCB levels that markedly exceeded all know marine mammal PCB toxicity thresholds’ … click here to read the Nature article