Mercury is a naturally occurring element that can be toxic to people and wildlife. Mercury has also been added to numerous products historically. Human activities including improperly disposing of mercury-containing products or burning fossil fuels which contain trace amounts of mercury have increased the amount of mercury deposited in the environment. When mercury enters aquatic ecosystems, primarily through atmospheric deposition, mercury is often converted to methylmercury (an organic form) which is bioaccumulated and magnified up the aquatic food chain. This can pose a risk to humans, primarily the unborn child and young children, as well as wildlife that consume fish with elevated levels of methylmercury. Michigan provides guidelines for eating safe fish that have lower levels of methylmercury. Elemental mercury Hg(0) is a heavy, silvery-white metal which is liquid at ordinary room temperature and has been used in many man-made products (thermometers, fluorescent light bulbs, etc.). At room temperature, Hg(0) evaporates to become an invisible, odorless, and toxic vapor. The hazardous route of exposure is inhalation of mercury vapor which is often associated with the inadequate cleanup of broken mercury-containing products. The most powerful and simple action that you can do to prevent this is by purchasing of mercury-free alternative, such as a programmable mercury-free thermostats.

EGLE has outlined many more activities to reduce the use and release of mercury in the environment and can be found in the EGLE Mercury Strategy. EGLE also developed a plan called a Total Maximum Daily Load for how much atmospheric deposition of mercury should be reduced in order for the fish in the state to be safe to eat.