Comparative analysis of distributions of radioactive cesium and potassium and stable cesium, potassium, and strontium in brown rice grains contaminated with radioactive materials released by the Fukushima Daiichi Nuclear Power Plant accident

The distributions of 137 Cs, 134 Cs, and 40 K as well as stable Cs, K, and Sr in bran, germ, and endosperm of brown rice contaminated by fallout from the Fukushima Daiichi Nuclear Power Plant were studied. It was found that 137 Cs, 134 Cs, and 40 K were accumulated in germ at the highest concentration and the concentration ratios of Cs and K in bran, germ, and endosperm were approximately identical to one another, while the highest concentration of Sr was detected for bran. Possible chemical forms of the metal elements in rice grains were discussed based on their extraction behavior with water and MgCl 2 aqueous solution.