Canned tuna is safe since the fish used are generally too young to have accumulated enough murcury to be toxic. The warnings are for older, fresh tuna, swordfish and the like. I did a lot of reading up on this a year or so ago when I first heard the mercury scare. I could be a case study... If I'm not dead yet, you're all safe.
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Keep your body lean, your blood clean and your mind sharp. -Rollins