Japan marine life faces threat from radioactive runoff
By ELISABETH ROSENTHAL and WILLIAM J. BROAD
Published: March 28, 2011 The announcement by Japan’s Agency for Natural Resources and Energy that high levels of radioactive cesium have been detected in seawater near the crippled nuclear reactors raises the prospect that radiation could enter the food chain. Cesium 137 levels were 20 times the normal level about 1,000 feet from the effluent at the Fukushima Daiichi nuclear power plant. That is far less than the level of the other main radioactive isotope spilling from the plant, iodine 131. It was found in concentrations of more than 1,150 times the maximum allowable for a seawater sample a mile north of the plant. Still, scientists say, cesium 137 poses the greater long-term danger to the marine food chain. … Cesium 137 … has a half-life of 30 years. Worse still, it is absorbed by marine plants, which are eaten by fish and — like mercury — tends to become concentrated as it moves up the food chain. “It’s worrisome in that CS 137 is leaking, although the levels are still low,” said Paul G. Falkowski, a professor at Rutgers University’s Institute of Marine and Coastal Sciences. “At some point this water that is pooling in various places is ultimately going to make its way out to the sea.” And if there is a lot of cesium 137 over an extended period “then you’ll have to worry.” …
