The Arctic has characteristic conditions for analyzing climate change and pollution effects. The area is relatively clean, but it receives long-range transported contaminants from long distances, primarily in the northern hemisphere. Furthermore, low temperatures alter common pollutant transportation mechanisms; for example, air pollutants can be deposited on ice through snow and retained for years until melting. The Arctic also has unique food chains; many species gather fat reserves for energy storage and insulation where pollutants are accumulated. The singular diet of autochthonous populations is based in these species and, as a consequence, Arctic populations suffer an inimitable situation: they live in relatively clean environments, but are strongly exposed to pollutants impact.