Spring 2014

Ask the Scientist: Fish Safety and Fukushima

Does eating fish caught off the U.S. West Coast pose a risk due to radioactivity from the Fukushima nuclear accident?

—Tsiwen Law, Philadelphia, PA

Edwin Lyman, senior scientist in the UCS Global Security Program and co-author of
Fukushima: The Story of a Nuclear Disaster (New Press, 2014), responds:

Computer simulations show that radioactivity released into the Pacific Ocean after the March 2011 accident should be reaching the West Coast now, but this radioactivity will have been greatly diluted during its travels across the sea. While there is no “safe” level of radiation, any exposure from fish caught along the West Coast is likely to be well below U.S. regulatory limits.

Much higher contamination levels persist closer to Fukushima, due in part to continuing leaks; the affected fisheries off Japan are being monitored and remain closed. Fish such as tuna that migrate away from these contaminated areas quickly flush out most of the cesium-137 (a by-product of nuclear fission) that they have ingested. However, other isotopes that accumulate in bones (e.g., strontium-90) can pose a greater hazard in fish typically eaten whole, like sardines.

While radiation from Fukushima presents little risk to Americans, it remains a severe threat in Japan, where tens of thousands cannot return to their homes. That situation is a stark reminder of the risks we face from nuclear plants here in the United States, where the Nuclear Regulatory Commission is not doing enough to address vulnerabilities to earthquakes and floods that could damage reactors or spent fuel rods stored on site.

Also in this issue of Earthwise:

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