Speaker
Description
After the Fukushima Daiichi Nuclear Power Plant (FNPP) accident in March 2011, a huge amount of radioactive cesium was released over a widespread area in eastern Japan. People were seriously concerned about food safety. Therefore, the Ministry of Health, Labor and Welfare established a provisional regulatory value of 500 Bq/kg for radiocesium in cereals, vegetables, meat, and fishery products. In April 2012, a new maximum limit of 100 Bq/kg was established as a new standard of radiocesium in general food. Since 2012 April, the results of monitoring has indicated that the violation rates were extremely low, much less than 1%, for agricultural products including cereals, vegetables and fruits, meat and milk, fish and fishery products, except for wild mushrooms. Even in 2018, several cities in Miyagi prefecture which locates 50-160 km north from the FNPP still prohibit the shipment of wild mushrooms. However, the decisions by the government do not always reflect the practical pollution of the wild mushrooms because of poor sampling data. We collected many edible wild mushrooms at several forests in Miyagi prefecture and investigated the frequency distribution of the radioactivity of the samples. We discuss annual, air dose rate and species dependences of the radioactivity concentration.
