Contaminants

The temperatures in the Arctic are so low for such long periods that there is limited decomposition of organic materials. Scavenging of materials on the land surface and sea floor is often quite complete, but waste materials like sewage and wood break down much more slowly than in more southern regions.

Chemicals introduced into the Arctic environment are not easily isolated from the plants and animals that live there. On land, exposed rock and permafrost in the soil prevent the isolation of substances below the ground, and substances can easily be washed into the ocean. In the ocean, sedimentation rates are slow enough that material is not readily buried. As a result, chemicals can be taken up by plants through absorption and by invertebrates during feeding. Once in the plants and animals at the bottom of the food web, they pass readily to other organisms higher up the web, including man.

Most Inuit and Inuvialuit continue to eat substantial amounts of food gathered from their local environment. In several Inuit communities there is evidence of the build-up of polychlorinated biphenyls (PCB's) in the people at concentrations far higher than found in people from southern communities where these chemicals were likely released.

Chemicals have been introduced into the Arctic in many ways, only a few of which have been studied. Long range transport of air pollution from more southern areas of the world has been a significant source of some materials. The Hadley Cell that carries warm air up at the equator, and cold air down at the poles, contributes to this effect, moving contaminants extremely long distances. More local spillage and disposal of chemicals from ships, settlements, and other operations carried on using southern technology have also added to the chemical burden in the food web.