The New York Times had tuna sushi from 20 Manhattan stores and restaurants tested for mercury, and they found levels so high, they freaked out the chefs and restaurant owners and everyone else.
Samples came from places we go, too: Nobu Next Door, Blue Ribbon, Gourmet Garage, Whole Foods, Megu. OK, so we don't go to Megu, but still. The in almost every case, a single sitting's worth of tuna contains enough mercury to reach the maximum level the EPA considers acceptable for non-pregnant, non-breastfeeding adults.
If you're pregnant or breastfeeding, or you're little, fuggedaboutit.
Grocery store sushi seems to be safer, mercury-wise, probably because it's less likely to be the highest grade bluefin tuna. Bluefin tuna are larger and get more mercury because they eat more fish. Yellowfin and albacore generally have lower levels.
Once again, the EPA and FDA are totally behind the curve on the subject. Sushi was never considered in the latest 2004 recommendations, and according to the toxicologist in charge, the guy you'd think would know this stuff, the FDA only "became aware" that Americans eat bluefin tuna "“A couple of months ago."
High Mercury Levels Are Found in Tuna Sushi [nyt]
Previously: You are what you eat, and for New Yorkers, that means mercury-laden fish
Uh: Sushi During Pregnancy? You're Eating For Two; Get The Platter.