Want some carbon monoxide with that mercury?

As if it's not enough that most tuna is tainted with mercury, now they're spraying fresh tuna sold in delis and sushi restaurants with--yum--carbon monoxide. Why? Because CO apparently keeps tuna looking fresh--even when it isn't. But don't worry; carbon monoxide is also found in wood smoke. So if you eat smoked fish, you're already eating carbon monoxide.

According to the NY Times, The Food and Drug Administration says the process is harmless. But Japan, Canada, and the countries of the European Union have banned the practice because of fears that it could be used to mask spoiled fish. In fact, says one CO distributor, "you could put it [CO-treated tuna] in the trunk of your car for a year, and it wouldn't turn brown."

http://www.nytimes.com/2004/10/06/dining/06TUNA.html?th