Fukushima radiation no longer a danger to seafood eaters, study proclaims

A new study aims to allay consumers’ fears about eating seafood that could have been contaminated by the Fukushima radioactive release after the massive earthquake and tsunami in Japan in 2011.

After testing tuna, swordfish, and sharks in the waters near Japan, Hawaii, and California, a team of international researchers found no detectable levels of cesium, a metal with a large number of radioactive isotopes.

“The cesium isotopes are of particular concern because they were discharged in large quantities following the disaster, exhibit relatively long half-lives (2.1 and 30 years respectively), and tend to accumulate in the muscle tissues that people like to eat,” according to a Virginia Institute of Marine Science blog post about the study.

Kevin Weng, an assistant professor at William & Mary’s Virginia Institute of Marine Science and a co-author of the study, gave eaters the thumbs-up in the blog post.

“Go ahead and eat some sushi! Our work shows that radioactivity from the Fukushima disaster is very low in open-ocean vertebrates,” Weng said.

Lead author Daniel Madigan, of Harvard University, agreed with Weng. 

“Our measurements and associated calculations of how much radioactive cesium a person would ingest by eating this seafood shows that impacts to human health are likely to be negligible,” Madigan said. “For marketed fish to be restricted from trade, the cesium levels would have to be more than 1,600 times higher than in any samples we measured.”

While earlier studies also showed extremely low risks from cesium, public concern over eating migratory species such as tuna persisted, the researchers said.

“People were very concerned about North Pacific salmon, halibut and scallops off British Columbia, and sea lions in Southern California,” Madigan said. “Our results, which show very low or undetectable levels in these animals, are important both for public perception of seafood safety and for scientific understanding of radionuclide transfer.”