Does frequent tuna consumption pose a health risk?

Question

PETA cite a story of boy who suffered from eating too much tuna:

Tuna fish accumulate toxic mercury in their flesh as a result of industrial pollution, and the side effects of mercury poisoning include finger curling, cognitive impairment, and coordination problems. A California boy, who was the subject of a front-page Wall Street Journal article, went from being a star athlete and honor student to being unable to concentrate or catch a football because he ate canned tuna.

I could not find the WSJ article.

Have there been cases of people experiencing adverse health effects caused by high tuna consumption (as in mercury poisoning)? Is there any research on the subject?

What is the safe daily limit of mercury consumption? How does measured tuna mercury content compare to this limit?

Answer 1

That's odd that they'd be calling out canned tuna. According to the EPA, canned tuna is safer than tuna steaks and is considered a "low mercury" fish. From the same article, they recommend up to 12 ounces of "low mercury" fish for pregnant women and children. For all others, they commend, at most, an RfD of 0.1 micrograms per kilogram of body weight per day. Consumer Reports did a study of mercury levels in tuna and found that the values varied greatly. They believe that 5 ounces (approximately 1 can) should be the limit for pregnant women due to at least 6% of the cans of tuna having enough mercury to hit the same upper limit as the EPA's 12 ounces.