Mercury in Fish

A review of fish advisories for mercury indicates the following:

• Most states issue advisories to warn people about elevated concentrations of mercury in non-commercial fish. In 2004, 44 states had advisories in effect for mercury in non-commercial fish. In some cases, advisories tell people to avoid eating fish from a particular area or a particular species. In other cases, they tell people to limit the amount of fish that they consume in general from a specified body of water. Some advisories are directed at protecting particularly susceptible groups, usually women of child-bearing age and children.
• Statewide advisories have shown the greatest increase. In 2004, statewide advisories for mercury in freshwater lakes and/or rivers were in effect for 21 states—Connecticut, Florida, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, New Hampshire, New Jersey, North Dakota, Ohio, Pennsylvania, Rhode Island, Vermont, Washington, and Wisconsin—up from five states in 1995 and 17 states in 2001. Twelve states had statewide advisories for mercury in their coastal waters and Hawaii had a statewide advisory for mercury in marine fish. Increased public health concerns have led to increased monitoring and this may explain, in part, the observed increase in statewide advisories.
• State programs for monitoring contaminants in fish and issuing advisories vary greatly. The absence of a state advisory does not necessarily indicate that there is no risk of exposure to unsafe levels of mercury in recreationally caught fish. Likewise, the presence of a state advisory does not indicate that there is a risk of exposure to unsafe levels of mercury in recreationally caught fish, unless people consume these fish at levels greater than those recommended by the fish advisory.
• Although some states monitor fish in a large number of water bodies, other states monitor few or none. The relationship between monitoring, setting of fishing advisories, and frequency of fishing has not been evaluated by EPA. Also, the concentration of mercury that triggers an advisory varies from state to state. As a result, the number of advisories does not directly represent the severity of contaminants in recreationally caught fish. It also reflects the extent of monitoring and the way that states assess risk.

EPA will work with other agencies to evaluate the feasibility of developing a measure more closely related to exposures that reflect mercury concentrations in fish intended for human consumption, for inclusion in future reports.

Related Measures:

• Prenatal Exposure to Methylmercury
• Neurodevelopmental Disorders