Manmade toxins such as polychlorinated biphenyls (PCBs) are threatening Arctic inhabitants. Scientists believe PCBs are leading to âgender-benderâ polar bears in Norway and Greenland, after discovering hermaphrodite female bears.
PCBs can take decades to breakdown, so are now largely banned in the West. Toxins build up in the foodchain, especially in fatty tissue such as blubber from whales and seals, a key part of the diet of polar bears and indigenous people of Artic. Though not believed to affect humans in the same way, is thought to be carcinogenic.