Mercury in the Environment



Richard H. Osa, QEP
STS Consultants, Ltd.
11425 West Lake Park Drive
Milwaukee, WI 53224-3025
(414) 359-3030
Michael G. McMurtry, M.D.
STS Consultants, Ltd.
10900 73rd Avenue N., Suite 150
Maple Grove, MN 55369-5547
(612) 315-6300


This presentation provides an overview of the potential health hazards to humans from exposure to mercury and mercury compounds. Mercury is a metal that occurs naturally in the environment in several forms. Elemental mercury can volatilize to mercury vapor at ambient air temperatures, which results in an increased potential for inhalation intoxication. If inhaled, mercury vapor can diffuse across the lining of the lungs and bind to red blood cells and cells of the central nervous system. Mercury and mercury compounds can also be absorbed through the skin or via the gastrointestinal tract after ingestion of contaminated media or foods.

Methyl mercury is one of the organic forms of mercury created by natural processes. Methyl mercury is of particular concern because it is highly bioaccumulative, i.e., it can build up in the fatty tissues of humans (including various tissues of the developing fetus) and in certain fishes within the aquatic environment. Exposure to high levels of elemental, inorganic, or organic mercury can permanently damage the brain, kidneys, lungs, and developing fetus. The human nervous system is particularly sensitive to mercury's toxic effects. This presentation discusses various risk-based criteria and standards for mercury compounds in environmental media and describes the toxicological basis for some of the most commonly used criteria.