A PRELIMINARY STUDY OF RELATIONSHIPS BETWEEN ELEMENTAL ACCUMULATION AND RADIOACTIVE CESIUM CONTAMINATION IN LENTINULA EDODES (SHIITAKE) BASED ON PIXE ANALYSIS

Particle-induced X-ray emission (PIXE) analysis of Lentinula edodes (Shiitake) mushrooms contaminated with radioactive cesium was performed to study relationships between concentrations of principal elements of shiitake mushrooms and their radioactive cesium levels. After the Fukushima nuclear disaster caused by the huge tsunami on March 11, 2011, we collected five shiitake samples in Marumori town, Miyagi Prefecture, on April 21, 2011. The mean radioactive level of the samples was 228 Bq/kg (the sum of 134Cs and 137Cs). The preliminary result of PIXE analysis using an internal standard method has demonstrated that shiitake mushrooms significantly collect rubidium as well as potassium. It is suggested that radioactive cesium is accumulated in shiitake just like rubidium during the course of potassium uptake.