UNLIKE most other pollutants, mercury is highly mobile, non-biodegradable and bio-accumulative. This toxic element therefore has to be closely monitored, to ensure that its harmful effects on local people are minimised. Mercury is distributed throughout the environment in a number of different forms. It exists mainly as elemental mercury vapour in the atmosphere. In its inorganic and organic form, it is present in water, sediments, soil, plants and animals. Small amounts of mercury are produced by natural sources, including volcanoes, forest fires and the weathering of mercury-bearing rocks. However it is anthropogenic or human activities which generate vast quantities of mercury- from fossil fuel combustion, solid waste incineration, mining and smelting to the manufacture of cement and the use of mercury cells in the commercial production of chlorine.
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