ICE CORES: Mercury (Hg)

Mt. Fremont Glacier, USA

Mercury (Hg) is a naturally occurring toxic trace element found in air, water, soil, and rocks. It is a heavy metal that is highly toxic to humans and the environment.  Mercury accumulates in the tissues of organisms inhabiting mercury contaminated environments which can be carried up the food chain to humans. Natural sources, such as volcanoes, are responsible for about half of atmospheric mercury emissions. The majority of human emitted atmospheric mercury originates from coal-fired power plants.  Ice cores reveal significant rises in atmospheric mercury during the 20th century.