Did you know that ingesting mercury is a doubleplusungood thing to do? Not exactly a shocking revelation, is it? Thanks to the EPA -- and the decline of coal -- we're doing a lot less of it today than we were 20 or 30 years ago. The largest single source of mercury in our diet? Tuna fish, particularly canned tuna. Since that accounts for about 40% of our exposure, it's gonna be a long time before it drops to second place, but things are getting better, and doing so faster than expected.