Mercury occurs naturally in the environment and can also be released into the air through industrial pollution. This mercury then falls into surface water, streams, and oceans, creating a potentially toxic substance called methylmercury. Fish absorb the methylmercury from water as they feed on aquatic organisms.
Nearly all fish contain trace amounts of methylmercury, but it is not harmful in such low levels. Long-lived, larger fish feed on other fish and accumulate the highest levels of methylmercury. These fish include shark, tilefish, swordfish, and king mackerel, and pose the greatest risk to people who eat them regularly.
The primary danger from methylmercury in fish is to the developing nervous system of the unborn child. Thus, pregnant women and women who may become pregnant should completely avoid these high-mercury fish. Additionally, it is important for nursing mothers and young children to avoid eating these fish as well.
Recommendation for Tuna
It is okay for pregnant women and women who may become pregnant to eat other fish as long as they limit total fish consumption to no more than twelve ounces total per week. As for tuna, the EPA (Environmental Protection Agency) recommends that you eat only 6 ounces or less of albacore tuna per week. Albacore is the white kind, and it contains more mercury than chunk light tuna.
For updates on the latest information in your area, contact the EPA for current advice on fish consumption from fresh lakes and streams. Also check with your state or local health department to see if there are special advisories on fish caught from waters in your local area. Furthermore, you can contact “Risks of Mercury in Seafood” by calling 1-888-safefood #9.