Some consumer groups are working to convince the U.S. Department of Agriculture to remove tuna from school cafeterias after a study found variable levels, sometimes higher than those allowed by Federal guidelines, of mercury in cans of the fish.
The Mercury Policy Project tested 59 samples of tuna in large cans and foil pouches from 11 States. Levels of methylmercury found were close to previous tests done by the Food and Drug Administration for the most part. But, levels of mercury varied widely, sometimes even in the same package. On average, methylmercury content ranged from 0.02 to 0.64 parts per million in light tuna and between 0.19 and 1.27 parts per million in albacore tuna.
“On any given day in a given school, children eating the same meal could get mercury doses that vary by tenfold, just because of the variability of the chunk of meat in the packet,” says Edward Groth, author of the report on the test.
The Environmental Protection Agency says the most methylmercury, a potent neurotoxin, that a person should consume equals one-tenth of a microgram per kilogram of their body weight. Miniscule levels of methylmercury have been linked to learning disabilities and developmental delays in children.
Even consuming tuna four times a month could have “subtle adverse effects” on some children, according to Groth.