(CN) — The U.S. Environmental Protection Agency has approved new criteria for levels of mercury in California fish.
Mercury is an extremely toxic metallic element that can cause severe damage to the brain and other organs. It often builds up in the bodies of fish, making it unsafe for people to eat. Pregnant women and their fetuses are at particular risk for mercury exposure from fish.
In California, mining operations during the Gold Rush released tons of mercury into waters.
On July 14 the EPA approved maximum levels of mercury for fish caught for sport, subsistence and cultural practices.
Many California tribes have historically depended on salmon and other fish for subsistence.
The new rules include criteria for levels of mercury allowed in fish from California’s inland surface waters, enclosed bays and estuaries.
There are five different criteria for mercury levels: tribal subsistence fishing, general subsistence fishing, prey fish, sport fish, and fish commonly eaten by the least tern – a protected migratory bird.
State Water Board Chairwoman Felicia Marcus called mercury in waters “largely a legacy of the Gold Rush era” that is difficult to manage.
“This approval is an important step in focusing attention on what can be done to limit exposures,” Marcus said.
The nonprofit Environmental Working Group has been sounding the alarm over mercury in fish in recent years.
The group has been highly critical of the government’s dietary advice for pregnant women, saying the risk of mercury exposure could outweigh the benefits of consuming omega-3 fatty acids.
“Federal guidelines fall short on protecting women who are pregnant or planning to have children,” said Michael Bender, director of the Mercury Policy Project. “Based on the evidence, it’s time for FDA and EPA to revise their advice, particularly when it comes to reducing tuna consumption, since it’s the largest mercury exposure in the American diet.”
Last year, a study published by the Scripps Institution of Oceanography concluded that mercury contamination of ocean fish dropped by about 50 percent between 1969 and 2012.