The Current Limits for Radionuclides in Food in Japan

After the TEPCO Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, the current limits in Japan on the radionuclide contamination of food [100 Bq kg for general foods, 50 Bq kg for milk and infant foods, and 10 Bq kg for drinking water as radioactive cesium (Cs + Cs)] were established on the basis of an effective dose of 1 mSv y, consistent with international standards to mitigate the exposure of the general public to radiation. Measures that include recalling or restriction of food have been taken in cases when these limits were violated. As a result of these efforts, the actual effective doses of radioactive cesium (Cs + Cs) in foods approximately 1 y after the FDNPP accident were below 0.01 mSv y. However, there is little information on the current status of these limits in the literature, which necessitates a comprehensive review of the information that exists. In this paper, the concept behind the introduction of these limits, the methods by which they were derived, and the results of monitoring food accordingly, are reviewed. This information will be helpful in the case of a future accident, and it will also help to enhance the understanding of the current limits and to relieve the anxieties of the general public concerning radiation exposure from radionuclides in food.