| Mercury | Northeast Regional Mercury TMDL | Northeast States §319(g) Petition for Mercury |
Water Quality | Mercury
Mercury in the Environment
Scientists believe that atmospheric deposition contributes a large portion of the mercury found in waterbodies and soil. Mercury is released into the environment by both anthropogenic and natural processes, but the majority of mercury sources are of human origin. Natural sources include volcanic eruptions, weathering of rocks, forest fires, and emissions of previously deposited mercury by biologic processes. Anthropogenic sources include fossil fuel burning, burning or land filling of mercury-containing waste, manufacturing and recycling facilities, laboratories, hospitals, dental offices, and breakage of products that contain mercury (such as fluorescent bulbs and mercury thermometers).
Mercury is emitted to the atmosphere as a gas or as particulate matter. It can then return to the earth’s surface by wet deposition when it becomes incorporated into rain or snow, or by dry deposition when it settles out of the air. Erosion, rainfall, and leaching transport mercury from the land to waterbodies. Mercury circulates through the environment in liquid and gaseous states and in both inorganic and organic forms. Elemental mercury, in liquid form, is the form that is found in many consumer products. Once exposed to the atmosphere, liquid elemental mercury vaporizes into a gas. The most common organic form of mercury is methylmercury. Bacteria that process sulfate in the environment take up mercury in its inorganic form and convert it to methylmercury through metabolic processes. Methylmercury is highly bio-accumulative and persistent in human, animal, and fish tissue.
For more information about mercury, contact Susy King, our mercury coordinator.