One Tuna Sandwich, Hold the Mercury
by Environmental Defense Fund
The humble tuna fish sandwich is a lunchbox staple. But tuna, like other large fish, contains higher-than-average amounts of mercury.
Mercury is particularly harmful to children. It can damage a child’s nervous system, brain, heart, kidneys and lungs. But parents and kids need not give up their tuna sandwiches altogether.
How much canned tuna is okay to eat?
There are two main kinds of canned tuna: chunk light and solid/chunk white (albacore). Albacore is a larger species of tuna, so its mercury levels are about three times those of the smaller skipjack, which accounts for most canned light tuna.
.For this reason, parents should limit the amount their kids eat:
1. Canned white, or albacore. Children up to age six can safely eat it once a month (3 oz. portions); children ages 6–12, twice a month (4.5 oz. portions). Adults, including pregnant women, can safely eat it three times a month (women, 6 oz. portions; men, 8 oz. portions). Some seafood retailers offer canned white albacore that contains significantly less mercury than well-known national brands.
2. Canned light—the safer choice. Children up to age six can safely eat it three times per month. Older children and adults can safely eat it once a week. But products labeled “gourmet” or “tonno” may contain mercury levels comparable to canned white.
3. A better alternative to tuna is canned salmon (mostly sockeye or pink from Alaska), which is low in contaminants and high in heart-healthy omega-3s. It’s also sustainably caught.
How mercury gets in tuna.
Mercury is emitted from coal-fired power plants and other industrial sources. It drifts through the atmosphere and rains down on rivers, lakes and the ocean.
In the water, bacteria convert the metal into toxic methylmercury, which builds up in the tissues of marine animals. As bigger fish eat smaller fish, mercury accumulates, so top predators like tuna, king mackerel and swordfish are the most contaminated.
One tablespoon of mercury every year, deposited continuously in tiny amounts, can make fish in a 20-acre lake unfit to eat.
Tuna is the second most popular seafood in the United States, after shrimp, and the average American eats more than 2.5 pounds of it per year.
FDA’s guidance is lacking
The Food and Drug Administration (FDA) has mercury standards for fish, but it inspects less than 0.1% of imported seafood annually (most U.S. seafood is imported). Worse, says EDF expert Timothy Fitzgerald, the FDA provides little guidance on safe consumption of fish. That’s why EDF developed their Seafood Selector health advisories.
Lower-mercury albacore tuna
Some retailers offer lower-mercury canned albacore, using smaller fish sustainably caught off the West Coast.:
EcoFish sells canned albacore caught by small family boats in the Pacific Northwest.
Wild Planet Foods sources tuna caught by responsible catch methods.
Island Trollers offers albacore “caught one at a time” off the North Pacific coast.
High Seas Tuna also comes from well-managed fisheries in Northwest waters.
...and last but definitely not least...
And finally: which fish are safe to eat? Click here to find out!
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