PIXE analyses of cesium in rice grains

The Fukushima nuclear power plant accident released vast amounts of radioactive material into the environment. For instance, 134Cs and 137Cs have half-lives of about 2 and 30 years, respectively, and emit many harmful gamma rays. In 2012, rice with radioactivity >100 Bq/kg was occasionally reported in Fukushima prefecture. To determine where and how cesium accumulates in rice, we grew rice in soil containing stable cesium and investigated the distribution of cesium in rice using particle-induced X-ray emission (PIXE). This study found that cesium is accumulated in bran and germ at high concentrations, and white rice contains 40% of the cesium found in brown rice