Predatory fish such as large tuna, swordfish, shark and mackerel can have mercury concentrations in their bodies that are 10,000 times higher than those of their surrounding habitat. Humans risk ingesting dangerous levels of mercury when they eat contaminated fish. read more
While certain fish such as shark, marlin and swordfish contain higher levels of mercury, sardines are classed among the lowest mercury-containing fish. The American Pregnancy Association advises that pregnant women and those looking to conceive should limit their intake to two 6-ounce servings each week. read more