Industrialized and developing nations emit about 2,000 tons of mercury into the atmosphere every year. Globally, the largest sources include emissions from small-scale and artisanal gold mining and coal-burning power plants. In the Arctic, high levels of mercury are found in beluga whales, polar bears, seals, fish, eagles and other birds. This means that humans are also affected, particularly the Inuit, who rely on traditional hunting and fishing for food. Exposure to high levels of mercury over long periods can lead to neurological and cardiovascular problems.
— source scientificamerican.com