The bears have been found with both male and female sexual organs. Scientists say chemicals used in heavy industry are causing the abnormalities, which could eventually lead to the bear's extinction. PCBs are industrial chemicals known to damage hormonal systems, causing infertility and sexual deformities. They also attack the immune system, and in high cases can be fatal. Polar bear research scientist Andrew Derocher said the effects of PCBs on the polar bear could be devastating.
Research indicates there are hot spots of PCBs scattered across the Norwegian Arctic.
They are believed to be carried to the Arctic Circle in air and sea currents from Europe and Asia. Most countries banned PCBs in the 1980s, but once released into the environment they can persist for decades. The polar bear suffers because it is at the top of a food chain. At each step in the food chain, more PCBs accumulate in the body fat. The polar bear cubs are in the greatest danger because they receive very high doses through their mothers' milk.