Mercury: A Persistent Pollutant and Threat to Brain Development In Children

Protecting Patients, Preventing Emissions, and Eliminating Sources

Mercury, a natural metal that does not break down, is a recognized hazardous pollutant that is extremely persistent in our environment.

After being released to the atmosphere, mercury settles into water bodies, where it is transformed by bacteria into methylmercury. In this form, it becomes more concentrated at higher levels of the food chain. Consequently, the highest levels are found in large, predatory fish and in fresh water fish that are closer to sources of mercury pollution.

People are exposed to mercury mainly by eating contaminated fish. A mere gram (1/28 oz.) of mercury emitted into a 20-acre lake can cause fish to become unsafe for human consumption.

Exposure to very low doses of mercury during vulnerable periods of brain development may result in impaired attention, memory, verbal learning, vocabulary, and neuromotor function. The Environmental Protection Agency (EPA) estimates that 52,000 to 166,000 pregnant women consume at or above safe levels of mercury. According to the National Academy of Sciences (NAS), more than 60,000 U.S. children are born each year at risk for adverse neurodevelopmental effects, including poorer school performance, due to in utero exposure to mercury.

Reducing Emissions From Incinerators and Coal-Fired Power Plants

Municipal waste incinerators and coal-burning power plants are the largest sources of mercury released in Massachusetts. Together, with other industrial sources, they emit more than 10,000 pounds of mercury into the air each year.

In response to the inherent danger of these emissions, at Interim Meeting 2000 the MMS adopted a resolution to support maintaining the Massachusetts moratorium on new waste incinerators and has supported strict mercury emission limits for coal power plants in Massachusetts.

Reducing Mercury Use in Medical Facilities

Mercury is also found in many instruments and supplies regularly used in medical institutions, such as blood pressure monitors, thermometers, and batteries for diagnostic and therapeutic equipment. Mercury-containing products are used in patient areas and pathology labs, in clinical procedures (to provide radio-opacity in imaging studies, for example) and in medicines.

Mercury-free alternatives are available for each of these products.

The American Hospital Association and the EPA are collaborating to develop a Mercury Waste Virtual Elimination Plan, in the hopes of eliminating mercury-containing waste from the health care industry waste stream by the year 2005.

Help Eliminate the Waste

The MMS encourages physicians and hospitals to continue the process of phasing mercury-containing medical instruments and products out of medical care facilities.

Those who purchase supplies and equipment should insist on disclosure of their mercury content by manufacturers and suppliers. This will enable informed purchasing decisions and identify targets for substitution.

– Jill Stein, M.D., and Ted Schettler, M.D.

For information about mercury-containing equipment in medical facilities, visit http://www.epa.gov/seahome/mercury.html.

For information about mercury in fish, go to the article Protecting Patients: Fish Consumption Advisories.