It is frightening that we can't manage to prevent PCBs escaping into the environment and into the food chain. Environmental toxins are accumulated and stored in adipose tissue. Polar bears, which live on seal, are particularly vulnerable. Scientists are also concerned about PCB levels among the Inuit people, for whom seal is also an important part of the diet. PCBs have even been detected in the breast milk of Norwegian women.
Scientists are able to trace the toxin from species to species and from generation to generation.
In mammals, environmental toxins are transmitted to the foetus via the placenta, and to the young through the mother's milk. When adipose tissue is broken down, PCBs are released into the body. Denning Some polar bears keep to their own area, others roam widely. Some bears have been registered travelling as much as 3,000 km in four or five months. The scientists' primary problem is that environmental toxins have different effects on different species.