Fukushima Radiation in Seafood Lower than Naturally Occurring Levels, Study Says

Radioactive elements found in fish as a result of the Fukushima nuclear disaster in Japan are comparable to, or even less than, the radiological doses in other commonly consumed foods, according to new research from an international team of scientists.

The Fukushima incident resulted in a number of environmental setbacks, including a large quantity of radioactive water being dumped in the Pacific Ocean. The news prompted intense media inquiries into possible risks presented by the levels of radioactively present in seafood following the meltdown of Japan's Fukushima Daiiichi reactor following a March 2011 earthquake and tsunami.

In response to reports of radioactive Cesium isotopes found in Pacific bluefin tuna following the Fukushima incident, researchers from the School of Marine and Atmospheric Sciences at Stony Brook University, France's Institute for Radiological Protection and Nuclear Safety and Stanford University's Hopkins Marine Station tested for radiation attributable to Fukushima as well as naturally occurring radionuclides found in marine animals and human fish consumers.

"We showed that doses in all cases were dominated by the naturally occurring alpha-emitter [Polonuim-210] and that Fukushima-derived doses were three to four orders of magnitude below [Polonuim-210-derrived] doses," the researchers wrote in the abstract to their paper, which was published by the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

From Pacific bluefin tuna, the scientists found radiation levels were "comparable to, or less than, the dose all humans routinely obtain from naturally occurring radionuclides in many food items, medical treatments, air travel, or other background sources."

Lead study author Nicholas Fisher said for American and Japanese seafood consumers, "the doses attributable to Fukushima-derived radiation were typically 600 and 40 times lower, respectively, than the dose from polonium."

"In estimating human doses of the Fukushima-derived radioactive cesium in bluefin tuna, we found that heavy seafood consumers - those who ingest 124 kg/year, or 273 lbs., which is five times the US national average - even if they ate nothing but the Cesium-contaminated bluefin tuna off California, would receive radiation doses approximately equivalent to that from one dental x-ray and about half that received by the average person over the course of a normal day from a variety of natural and human sources. The resulting increased incidence of cancers would be expected to be essentially undetectable," Fisher said, according to a phys.org report.