Mercury & Human Health Ann Melamed R.N., M.A. Environmental Health Specialist American Nurses Association May 2004

How Does Mercury Get into the Environment?

Incineration When mercury-containing waste is incinerated, the mercury is vaporized into the air. According to the U.S. EPA, medical waste incinerators are the fourth largest source of mercury to the environment 1. The Agency for Toxic Substances and Disease Registry (ATSDR) estimates that medical and municipal waste incinerators are responsible for 30 percent of the total mercury emissions to air 2.

Landfill When mercury-containing devices are disposed in the landfill, mercury can reenter the environment through gases released by landfills, and through leaching into the ground water. Mercury fever thermometers alone contribute about 17 tons of mercury to solid waste landfills annually. 3

A single fever thermometer contains one gram of mercury 4 grams of mercury are sufficient to contaminate a small to medium sized lake rendering the fish in that lake unfit for consumption by women of child bearing age

Water Discharges When mercury-containing waste (including fixatives, medicine, cleaning solutions) are dumped down the drain, the mercury eventually returns to the water supply, and is converted to methylmercury by bacteria in sediments. Methylmercury bioaccumulates in aquatic animals, and the concentrations can increase by a million fold in animals at the top of the food chain.

Exposures to Humans Methylmercury is 100% absorbed through the GI tract and distributed through the body. The primary pathway for mercury to impact human health is through eating mercury- contaminated fish. Forty-two states post fish consumption advisories because of widespread mercury contamination.

Health Effects of Mercury As a reproductive toxin and a potent neurotoxin, mercury affects the brain and the central nervous system. Pregnant women, women of childbearing age, and small children are at greatest risk. Mercury can cross the placenta and cause irreparable neurological damage to the fetus.

Neurological Damage A National Academy of Sciences report from July 2000 showed that 65,000 babies born in the United States each year are at risk of neurological damage due to their mothers eating mercury-contaminated fish. In March 2001 a study from the Centers for Disease Control (CDC) found that 1 in 10 women have mercury levels high enough to cause neurological damage in their children- about 400,000 babies a year.

Children’s Special Vulnerability Children are not “little adults.” Children’s immature organ systems are expecially sensitive to environmental hazards. Exposure to toxics such as mercury can cause permanent damage to the developing nervous, immune and respiratory systems of young children. Pound for pound children eat, drink and breathe more for their size than adults

Children’s special vulnerability The metabolic and physiological processes of children differ dramatically from those of adults, they absorb more through GI tract, skin and respiratory systems than adults. Children’s normal hand to mouth activity and crawling increase opportunities for exposures to toxics.

References and Resources Mercury Report to Congress Toxicological Profile (Update) for Mercury. Agency for Toxic Substances and Disease Registry. 3. (U.S. Environmental Protection Agency, 1996, Mercury Study Report to Congress, Science Advisory Board Review Draft, Vol. 2, p. 4-19, p. ES-3.) Health Care Without Harm Hospitals for a Healthy Environment online.org American Nurses Association