|Consumers should continue to limit their intake of shark, swordfish, king mackerel or tilefish, according to a joint advisement by the EPA and FDA. They say that these fish have high levels of mercury found especially to be harmful for a young child's developing nervous system and pregnant and nursing women.
As a substitution, since they say fish and shellfish are an important part of a healthy diet because they are a source of high-quality protein, many vitamins and minerals, omega-3 fatty acids and are mostly low in saturated fat, the two agencies suggest choosing shrimp, canned light tuna, salmon, pollock and catfish.
Women since 1999 apparently have heeded the warning. For the peer-reviewed study, "Trends in Blood Mercury Concentrations and Fish Consumption among U.S. Women of Childbearing Age," NHANES (1999-2010), EPA analyzed measurements of blood mercury levels from CDCís National Health and Nutrition Examination Survey. EPA found that blood methylmercury concentrations in women of childbearing age in the first survey cycle (1999-2000) were 1.5 times higher than the average concentration of the five subsequent cycles (2001-2010). The average of blood mercury concentrations changed only slightly from 2001 to 2010, and remained below levels of concern for health.
In 2013 the EPA reports that they took two significant actions toward making fish and shellfish safer to eat. In June, the agency proposed new effluent guidelines for steam electric power plants, which currently account for more than half of all toxic pollutants discharged into streams, rivers and lakes from industrial facilities in the U.S. In April, EPA issued the new Mercury and Air Toxics rule, which sets emissions limitation standards for mercury emitted from power plants. Compliance with this rule, however, may take up to four years.