We selected and re-categorized the monitoring data opened by the government of Fukushima prefecture focusing on the radiocesium concentrations in four agricultural products, from the data on 90,000 samples analyzed during 3 years. Radioactivity was found to be high during 3 months after the accident because of direct fallout. The internal exposure in the area with the highest contamination area of rice during the first 3 months was calculated and estimated to be 0.75 mSv year−1. The radioactivity in foods products rapidly decreased after 3 months later, but in the case of some forestry products and fish, there are still some products in which radioactivity was above the regulated value, 100 Bq kg−1
