Based on those results, the Department of Health recommends that healthy adults eat no more than 7 ounces of fish per week with mercury levels close to or slightly above 1ppm. Women who plan to become pregnant, are pregnant or are breast-feeding, and children under age 7 should eat no more than one 7 ounce meal of such fish per month. Seven ounces of fish is equal to two medium-size portions or roughly the size of two decks of playing cards.
Fish is an important source of high-quality protein that provides many health benefits.
Micklos said that the various federal agencies disagree on what daily dose of methyl mercury is acceptable. However, all agree that when levels reach 1ppm, meals should be spaced to prevent potentially dangerous mercury accumulation. Commercially caught species, mainly shark and swordfish, commonly have mercury levels around 1ppm and FDA recommends consumers limit their consumption. The FDA action level is also used by the Department of Health to issue consumption information to the public. The FDA level is 10 times lower than the lowest levels associated with negative neurological effects observed in mercury poisoning incidents.