Is any exposure to mercury harmful to people?

High levels of mercury in the bloodstream of unborn babies and young children may harm the developing nervous system. Whether an exposure to mercury will harm a person's health depends on a number of factors. Almost all people have at least trace amounts of mercury in their tissues, reflecting mercury’s widespread presence in the environment. People may be exposed to mercury in any of its forms under different situations. The factors that determine how severe the health effects are from mercury exposure include: 

• •The chemical form of mercury - i.e. elemental (metallic), inorganic compounds, or organic compounds
• •The dose - i.e. how much
• •The duration of exposure - i.e. how long
• •The route of exposure - i.e. eating, breathing, injecting, touching
• •Other chemical exposures
• •The specific characteristics of the person - i.e. age, health

Anyone who has concerns about mercury exposure should consult a doctor. Doctors may be able to identify exposure and health risks by measuring the amounts of mercury in blood, urine, breast milk, finger and toenails, and hair. Over time, the body can rid itself of some mercury. Methylmercury is removed from the body naturally, but it may take months to a year for the levels to drop significantly.

The effects of mercury exposure can be very severe, subtle, or may not occur at all, depending on the factors above. Mercury can affect the nervous system. Because fetuses, infants, and children are still developing, they are particularly sensitive to the effects of methylmercury on the nervous system. People are mainly exposed to methylmercury, an organic compound, when they eat fish and shellfish that contain methylmercury.

You can find more detailed information about health effects that may result from exposure to mercury (http://www.epa.gov/iris/subst/0370.htm) and methylmercury (http://www.epa.gov/iris/subst/0073.htm) by visiting the Health Effects section of the EPA Mercury Web site: http://www.epa.gov/mercury/effects.htm, and the Integrated Risk Information System (IRIS) database: http://www.epa.gov/IRIS/. You can also visit the Agency for Toxic Substances and Disease Registry (ATSDR) toxicological profile for mercury: http://emergency.cdc.gov/agent/mercury/index.asp    For further information on the EPA/FDA fish advisory, visit our Fish Consumption Advisory page: http://www.epa.gov/mercury/advisories.htm.

For additional information on mercury please visit the EPA Mercury Web site: http://www.epa.gov/mercury/