Fish that may contain mercury

When mercury builds up to toxic levels in the human body, it can cause permanent neurological damage. If you are pregnant, mercury is dangerous to your developing fetus and later to your breast-feeding baby. A fetus exposed to mercury during pregnancy is especially likely to suffer mild to severe nervous system damage. Similarly, young children who eat a lot of fish containing mercury can suffer permanent brain damage.

Mercury occurs naturally in the environment and also as a result of industrial pollution. It is in our water, air, soil, and food. Fish are the most common source of mercury in the human diet. You can best protect your child from mercury exposure by avoiding high-mercury fish before and during pregnancy and when breast-feeding and choosing foods for your young child.

The U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) have issued the following advisory for pregnant women, women of childbearing age, nursing mothers, and young children:¹

• Avoid eating fish most likely to have high levels of methyl mercury, including shark, swordfish, king mackerel, and tilefish. Large, long-lived, predatory ocean fish have the highest mercury levels.
• Do eat up to 12oz a week of fish or shellfish that are known for their health benefits and low mercury risk. Your top five most available choices include shrimp, canned light tuna, wild salmon, pollack, and catfish. Fish sticks commonly prepared for children are typically made from low-mercury fish. Since mercury can be found in small amounts in any fish, generally avoid eating more than 12oz per week.
• Exercise caution when eating albacore (white) tuna, which has more mercury than canned light tuna. Limit this type of tuna to 6oz per week.
• Before eating locally caught fish, check with your state or local health department for information about water and fish contamination. Also check the Environmental Protection Agency Web site for mercury advisory updates at http://www.epa.gov/ost/fish.

Mercury will slowly leave the body over time in the urine, feces, and breast milk. If you are concerned about your own or your child's mercury level, talk to your health professional or local health department about testing.

Citations

1. U.S. Food and Drug Administration (2004). What you need to know about mercury in fish and shellfish: 2004 EPA and FDA advice for women who might become pregnant, women who are pregnant, nursing mothers, young children. Available online: http://www.epa.gov/ost/fishadvice/advice.html.