US Geological Survey



Date of this Version



Published in U.S. Geological Survey Circular 1248 by the U.S. Geological Survey, 1-47, (2003)


A liquid at room temperature, mercury is a unique metal with unusual properties. Elemental mercury has long been used in thermometers because it responds to changes in temperature. In fact, mercury’s many diverse properties have made it useful for many products. Mercury is a good metallic conductor with a low electrical resistivity; it has been used in electrical products including electrical wiring and switches, fluorescent lamps, mercury batteries, and thermostats (Eisler, 1987). Mercury also is used in navigational instruments to measure changes in temperature and pressure. In the medical field, mercury is used as a component in dental fillings and as a preservative in many pharmaceutical products. Mercury has been used in industrial and agricultural applications such as in the production of chlorine and caustic soda, in nuclear reactors, in plastic production, for the extraction of gold (amalgamation) during mining, as a fungicide in seeds and bulbs, and as an antifouling agent in paper, paper pulp, and paint (Sznopek and Goonan, 2000).