We’re getting a better idea of how much radioactive material has entered the ocean around Japan’s crippled Fukushima Dai-ichi nuclear power plant. Bloomberg reports that damaged fuel rods have released five different kinds of radioactive material and contaminated nearby seawater:
Iodine-131 was detected at 127 times normal levels from sample water taken at 2.30pm yesterday, while caesium-134 levels were 25 times normal and caesium-137 was at 17 times normal, Tepco said on its website.
Ken Buesseler of Woods Hole Oceanographic Institution told Bloomberg that radioactivity levlels
“This time of year off the coast of Japan, they would mix with water down 100 feet to 300 feet, and be diluted by a factor of about 100. The currents there would move it to the south, just north of Tokyo, and then out to sea.”
The ocean’s vast capacity to dilute out the radioactive material means that the nuclear crisis is unlikely to impact ocean life or create a seafood safety issue. As Ken told me last week, the Black Sea remained safe for swimming and eating seafood despite Cesium-137 levels 10-20 times normal after Chernobyl. Localized contamination of seaweed with radioactive iodine could be a concern for Japanese consumers, but iodine decays rapidly and will be gone within a month.
Similarly, Bill Camplin, group manager of radiological and chemical risk at the Centre for Environment, Fisheries and Aquaculture Science in Lowestoft, England, told Bloomberg the radioactive material poses a much greater risk to land-based food supplies.
“But my advice would be not to eat seafood caught from within the evacuation and sheltering zone,” or about 30 kilometers offshore, Camplin said in an e-mail. “Effects on wildlife in the sea are unlikely to be severe.”
The U.S. Food and Drug Administration is attempting to reassure American consumers about the safety of imported seafood, saying it is monitoring the situation closely:
Based on current information, there is no risk to the U.S. food supply. FDA is closely monitoring the situation in Japan and is working with the Japanese government and other U.S. agencies to continue to ensure that imported food remains safe.