Division of Environmental Quality fact sheet
Division of Environmental Quality Director: Kyra Moore
Reduce mercury in homes and businesses graphic image

Mercury exposure can cause neurological and developmental disorders in humans. Young and unborn children are at greatest risk from mercury exposure because their nervous systems are still developing. High-level exposures can cause severe birth defects, including blindness, deafness, cerebral palsy and mental retardation, and can even result in death. In low doses, mercury may delay a child's walking and talking, shorten attention span and cause learning disabilities.

In adults mercury poisoning can cause problems with fertility and blood pressure. Early symptoms of mercury poisoning include insomnia, lack of appetite, irritability, reduced peripheral vision, pins and needles feelings, numbness, loss of coordination, slowed reaction times, memory loss and slurred speech. Short-term exposure (hours) to high levels of mercury vapor can irritate lungs and airways, cause tightness of the chest, a burning sensation in the lungs and coughing. Other symptoms of mercury exposure include nausea, vomiting, diarrhea, skin rashes and eye irritation.


The most common route of exposure for humans is from eating mercury contaminated fish or, in the case of fetuses and nursing babies, from consumption of contaminated fish by the mother. Inhalation of mercury vapors is another route of exposure. There have been a number of recent accidental and deliberate releases of elemental mercury in schools, homes and other buildings. Mercury almost immediately begins to evaporate at room temperature. The speed it evaporates is usually slow, however, it also depends how much it is moved or disturbed.  Breathing the vapors can cause mercury poisoning. When inhaled, about 80% of the mercury enters the bloodstream directly from lungs, and then is rapidly spread to the brain and kidneys. Mercury can stay in the body for weeks or months.

Learn more about the department's Dental Amalgam Rule.

More Information

For further information on health effects, check out the following websites: 

Nothing in this document may be used to implement any enforcement action or levy any penalty unless promulgated by rule under chapter 536 or authorized by statute.

For more information

Division of Environmental Quality


1101 Riverside Drive
PO Box 176
Jefferson City, MO 65102
United States