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A new study compares fish from 12 locations around the globe.

Jillian Kramer
August 10, 2017

First, here's the bad news: no matter what you do—no matter what brand you buy or where the fish was caught—the tuna you eat will contain some kind of pollutants. But according to a recent study, you can lower your exposure to pollutants by finding out where tuna was caught.

Researchers from the Scripps Institution of Oceanography at U.C. San Diego studied 117 yellowfin tuna dorsal muscle samples pulled from 12 locations around the world, logging the pollutants in each one. To be clear, every fish the team tested came back positive for persistent organic pollutants, but the more remote the area from which the tuna was caught, the fewer pollutants it contained, they found. That meant yellowfin caught in waters near industrialized North America and Europe had more pollutants—36 times more, to be exact—than fish captured in the West Pacific Ocean. Let that sink in—then check you tuna labels.

What kind of pollutants did the team discover in the tuna? To name just a few, the team found pesticides, flame retardants, and polychlorinated biphenyls when they measured pollutants using liquid or gas chromatography and mass spectrometry.

Interestingly, most of the tuna the team analyzed—including the samples with 36 times the amount of pollutants than others—would be considered safe to eat under both FDA and EPA current standards. However, the study revealed that 90 percent of tuna caught in the northeast Atlantic Ocean contained pollutant levels that would warrant health advisories for some people—think: pregnant and nursing women. The same was true for 60 percent of the yellowfin tuna caught in the Gulf of Mexico.

What can you do to protect yourself? Of course, it doesn't hurt to read the labels of the tuna you're purchasing to try to find fillets caught in the most remote regions. But unfortunately, mislabeling and fish fraud run rampant in the U.S. market, with a recent report revealing one-fifth of our seafood is somehow mislabeled. If there is a bright side, It may be that—chances are—you're not eating enough tuna for those pollutants to really hurt you. After all, we've known for a while that too much tuna can lead to mercury poisoning, right?

When you do purchase fresh tuna (and check the origin), here are some splurge-worthy recipes to make the most of it.