Northern overexposure.

The top of the world may look pristine, but the Arctic environment and its inhabitants contain surprisingly high levels of heavy metals, persistent organic pollutants such as pesticides, and nuclear radiation. Although the Arctic has few significant pollution sources, the contaminants are swept northward on ocean currents and winds from industrial regions. Once contaminants arrive, low temperatures and limited sunlight slow their decay, and bioaccumulation concentrates some of them to dangerous levels.