Ever since last Friday’s statement from the U.S. FDA concerning the alleged health effects of Bisphenol A, activists have been engaging in a full court press on the issue even in the face of the fact that FDA stated that it didn’t have sufficient evidence to ban the use of the chemical.

But that hasn’t stopped activists like Bruce Lourie, the author of Slow Death by Rubber Duck, who appeared earlier today on NPR’s Diane Rehm Show. After the host gave Lourie and and Rick Smith, an executive at the Environmental Defense Fund, more or less free reign to say whatever they pleased for most of the program, Lourie turned his sights to canned tuna.

Lourie said he normally ate a lot of tuna and believes that it’s part of a healthy diet. As part of his book, he conducted an experiment over a 48-hour period where he ate seven meals of either canned tuna or tuna sushi and then had his blood tested for mercury. If the trick sounds familiar, that’s because it’s essentially the same unscientific experiment that Sue Kwon of KPIX-TV in San Francisco tried to pull back in March 2009. If you have the time, be sure to watch our rebuttal video for a quick refresher. Lourie said that according to the results, his blood contained a level of mercury above what EPA considered to be safe, though, unlike Kwon, he failed to mention what that level might be. In any case, what was most egregious wasn’t just the fact that he passed off his little stunt as legitimate science, but that he said that as far as he was concerned, that the results indicated to him that anyone who is pregnant shouldn’t eat tuna at all. Of course, that flies in the face of the established FDA advisory that says that pregnant women can eat up to 6 ounces of albacore tuna per week, or 12 ounces of light tuna. It also ignores the conclusions of a study published in The Lancet that said that increased mercury levels in pregnant women may actually be a marker for better brain development in babies because it indicates that a woman regularly eats plenty of seafood.

The lesson here ought to be instructive: the question is not whether or not seafood contains mercury or that consuming seafood increases blood mercury levels. Instead, the real question is whether or not those trace levels of mercury cause any harm — and when it comes to that question, there’s plenty of science to indicate that it doesn’t.