National Geographic Channel
For many, the Arctic is synonymous with a pristine, albeit harsh, environment. So it is an unwelcome irony, perhaps, that the region's indigenous peoples and animal predators are reportedly among the most chemically contaminated on Earth.
Various studies in recent decades have found that animals from polar bears to killer whales, not to mention native peoples like the Eskimos, or Inuit, carry unusually high levels of human-made chemicals in their bodies.
These toxins include industrial pollutants like dioxin and PCBs, which gained notoriety during the 1970s, and newer compounds like those now used as flame retardants and stain guards.
The chemicals reach the Arctic borne north by wind and ocean currents. "The chemicals that accumulate in Arctic wildlife and people are coming from us," said Susan Sang, a senior manager and Arctic specialist for the Toronto-based environmental group WWF Canada.
For several decades researchers have studied toxin levels in Arctic peoples and wildlife and tracked pollution sources.
Peter Ross is a marine mammal toxicologist with the Canadian Department of Fisheries and Oceans in Sidney, British Columbia. He says scientists are now trying to take a difficult next stepestablishling a link between accumulated chemicals and health effects.
The potential health threat to humans and wildlife is considered serious enough to have prompted international action. In May 151 countries signed the Stockholm Convention on Persistent Organic Pollutants. The international treaty seeks to phase out use of 12 of the most dangerous persistent organic pollutants as soon as possible.
Infiltrating the Food Chain
Persistent organic pollutants are industrial chemicals that break down slowly and collect in the fatty tissues of animals. The toxins have been found to accumulate in ever larger concentrations in species higher up the food chaina process known as bioaccumulation.
In 1970 the insecticide DDT was found in the blubber of ringed seals in the Arctic. By the mid-1970s it was also found in beluga whales, polar bears, and fish.
Further tests discovered traces of some of the world's most toxic industrial chemicals, including polychlorinated biphenyls (PCBs) and dioxin, in Arctic wildlife.
In 1987 high levels of PCBs were discovered in nursing Inuit mothers in Nunavut, a semiautonomous territory in the Canadian Arctic. The finding raised concern about human health impacts.
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