Harris notes that, yes, “the tuna from Japan had picked up traces of radioactive cesium, according to Nicholas Fisher and Zofia Baumann at Stony Brook University, and Daniel Madigan at Stanford University, who co-wrote the article.”
But what Harris also notes is that the amount of radiation actually retained in these tuna specimens is relatively inconsequential:
“Yes, radiation in seafood seems scary. But here’s the catch (if you pardon the expression). Tuna, like every other food on the planet, already contains naturally occurring radiation. It has potassium-40 and polonium-210. It always has and it always will. In addition, seafood in general contains a trace of cesium-137 left over from nuclear weapons testing in the 1950s and 1960s.
So the question is, how much more radiation did these particular tuna fish contain? The answer is: A trivial amount. In fact, radiation from the cesium is 30 times less than the radiation that’s already in the fish naturally in the form of potassium-40, according to the research paper. And the natural polonium-210 packs a radiation dose 200 times larger than the dose from the cesium.”
Read the full piece here.