Report Finds Mercury in Tuna Sold to Schools

Tuna is a tasty, high-protein, low-fat food and it can even be prepared in recipes that kids like. But a new report finds that children may be at more risk from mercury in tuna than had previously been thought.

The report (PDF copy here), co-released by the Center for Science in the Public Interest (CSPI), Physicians for Social Responsibility, Safe Minds, and several other groups, advises schools and parents not to serve any albacore tuna to kids and to limit consumption of light tuna to twice a month for most kids and only once a month for smaller children (under 55 pounds).

The study by the Mercury Policy Project contains the first-ever test results of canned tuna sold to schools.  It also notes that new studies have found adverse effects of tuna consumption at lower levels than expected.

"Most children are already consuming only modest amounts of tuna and are not at significant risk," said Michael Bender, director of the Mercury Policy Project. "So the focus really needs to be on kids who eat tuna often, to limit their mercury exposure by offering them lower-mercury seafood or other nutritious alternatives."

"Fish, including tuna, is generally a nutritious part of a healthy diet," said Sarah Klein, staff attorney in the Food Safety program at CSPI. "But especially for our littlest, most vulnerable children, we have to make sure the risks from mercury in tuna don't outweigh tuna's benefits. We're urging parents and schools to limit children's tuna consumption and, when they do serve it, to choose lower-mercury options."

Not a low-mercury fish

"As the report states, light tuna has one-third as much mercury as albacore does," added Eric Uram of Safe Minds. "But contrary to the current Federal fish consumption advisory, it is definitely not a low-mercury fish."

The report points out that canned tuna is by far the largest source of methylmercury in the U.S. diet and accounts for nearly one-third of Americans' total exposure to this toxic mercury compound.

MPP tested the mercury content of 59 samples, representing eight brands of tuna, sold to schools in 11 states around the country.

"As far as we know, no one has previously tested this market sector," said Bender. Testing showed that the tuna contains mercury levels similar to what other investigations have found in canned tuna sold in supermarkets. Albacore or "white" tuna had much higher mercury levels than did "light" tuna, and mercury levels in both types were highly variable.

Canned tuna is inexpensive and nutritious, a low-fat protein source, and a popular lunch food for kids. American kids eat twice as much tuna as they do any other kind of fish, and one out of every six U.S. seafood meals is canned tuna. A tuna sandwich is an easy-to-fix parental favorite, and canned tuna is served through the federally subsidized school lunch program. And schools may be switching to leaner protein sources this fall as they implement the new school lunch standards.

The report offers these recommendations (among others):

1. Children should not eat albacore tuna. Albacore or "white" tuna contains triple the mercury level of light tuna; nothing justifies tripling a child's mercury dose.
2. Children weighing more than 55 pounds should not eat more than two servings of light tuna per month. This amount of tuna (six ounces) is more than the average child currently consumes; the mercury dose it contains is acceptably low in risk.
3. Children up to 55 pounds should consume no more than one tuna meal per month.Because of their smaller body size, an added margin of caution is appropriate for younger children.
4. "Tuna-loving" kids should be the focus of risk-management efforts. In particular:

• No child should eat tuna every day. (Tuna Surprise presents cases of children who did that, and were diagnosed with clinical methylmercury poisoning.)
• Parents and schools should offer children other seafood choices, such as shrimp and salmon, which are just as nutritious but contain far less mercury.
• The U.S. Department of Agriculture's School Lunch Program should phase out commodity purchases of canned tuna, and replace it with lower-mercury alterative seafood items and other extra-lean protein sources.
• Parents should monitor their children's canned tuna consumption at school and ensure that the total consumed at home and at school does not exceed the recommendations for exposure.