POPs such as these are dangerous substances that tend to break down slowly, travel through air and water to regions far distant from their original sources, build up in the tissues of organisms, and concentrate up the food chain.
POPs have the potential to injure humans and wildlife even at low concentrations.
Evidence has indicated that POPs have affected high predator species. Canada is a driving force for a POPs treaty. This is despite the fact that Inuit live many thousands of kilometres from virtually all sources of POPs. It has been shown that POPs can evaporate at their release point in the environment and condense again at a point sometimes many hundreds of kilometres away. Once there, the Arctic acts as a kind of cold trap.