Mercury is an element that occurs naturally through volcanic or geothermal activity and in ore, such as cinnabar. These natural sources account for about one-third of the total mercury load in the environment and are not the focus of the mercury action plan. But as a waste, highly concentrated amounts of mercury and mercury compounds end up in the air, land and water through myriad human causes that can and will be addressed in the Mercury Chemical Action Plan.
Mercury waste is found at mines, coal-power plants, refineries, laboratories, garbage incinerators, municipal sewage plants, auto wreckers and repair shops, cement plants and printing industries. Mercury is a naturally occurring constituent of fossil fuels, such as oil or coal.
When released into the environment, mercury can recycle through the air indefinitely or can bind with bacteria in water to create such compounds as methylmercury. When a fish eats organisms containing these bacteria, methylmercury is ingested and builds up in fish tissue. If a person eats a tainted fish, the methylmercury “load” is transferred to the human and lodges in numerous organs and tissues.
Several studies by the Department of Ecology have evaluated the presence of mercury in toxic cleanup sites, urban bays and other water bodies.