Title: Should We Be More Worried About Nuclear Sushi?
Source: OnEarth Magazine
Author: Brad Jacobson
Date: March 14, 2013
[...] Stories you’ll read about [Daniel Madigan, a marine biology graduate student at Stanford University] and his unsettling [California bluefin tuna] findings all have one thing in common: buried somewhere, usually about halfway down the page, is a paragaph telling you not to get too freaked out about the idea of hot tuna, given several facts. According to Madigan’s own report, the cesium levels he found in the tuna gave off less radioactivity than other, naturally occurring isotopes that could be found in the fish. The broader implication is that we’re all being exposed to varying levels of naturally occurring radiation (often referred to as “background radiation”) as we go about our daily lives. This “Don’t panic!” narrative is then typically reinforced with a comforting-sounding comparison between the amount of radiation you’re likely to ingest by eating Fukushima-irradiated tuna and the amount you’re likely to ingest by, say, eating a banana (which is rich in potassium, a radioactive isotope).
But maybe it’s actually worth unpacking that comparison just a bit.
For starters, the potassium in bananas — levels of which our bodies, via homeostasis, calibrate and keep at a relative constant — can’t be compared in good faith to a truly nasty radionuclide like cesium-137 [...]
But even more significantly, these comparisons rarely, if ever, cite in any depth the theory that has become a cornerstone of the modern science surrounding low-dose radiation exposure and its role in the eventual development of cancer. In a nutshell, this theory, which was developed in the late 1950s and is known today as the linear no-threshold model (LNT), holds that there is no agreed-upon “safety threshold” for ionizing radiation, and that in terms of cancer risk, there’s no real difference between one big dose of radiation and a bunch of little doses. [...]
In a 2012 ABC News report that ran in the wake of Madigan’s first bluefin study, Dr. Michael Harbut, director of the Environmental Cancer Program at Wayne State University’s Karmanos Cancer Institute, expressed his concern over the same unwillingness of authorities to be open with the public. “We don’t see people dying left and right all over the West Coast from radiation poisoning,” Harbut acknowledged. “But to say this is nothing to worry about is equally irresponsible, because you have radioactive material ingested by fish, which is in turn being eaten by people.” [...]
Published: March 15th, 2013 at 10:38 am ET