In a previous study, we reported the radiation dose owing to the ingestion of foodstuff and the effect of regulations using the accumulated monitoring results effectively as a preliminary study. Over 2,500,000 monitoring tests have been performed under the current criteria ( Table 1) until fiscal year 2020 (FY2020). Since the establishment of safety measures for radionuclides in foodstuffs in 2011, monitoring tests have been conducted using radiation-measuring instruments (e.g., a germanium semiconductor detector) to measure the radionuclide concentration in foods. The regulatory values of the current criteria are presented in Table 1. The current criteria for radioactive cesium (sum of cesium-134 (Cs-134) and cesium-137 (Cs-137)) were established based on an effective dose of 1 mSv/year, which is in harmony with a reference level adopted by the Codex Alimentarius Commission (CAC) based on publication 82 of the International Commission on Radiological Protection (ICRP). To deal with long-term situations, the present standard limits (current criteria) were established on 1 April 2012, through discussions in the Pharmaceutical Affairs and Food Sanitation Council. The value was 200 Bq/kg for the categories of drinking water and milk/dairy products and 500 Bq/kg for that of vegetables, grains, meat, eggs, and fish. ![]() The values for radioactive cesium were set as the radionuclide concentration for radioactive cesium based on an effective dose of 5 mSv/year. In Japan, the Ministry of Health, Labour, and Welfare (MHLW) established provisional regulatory values for radioactive substances in foods on 17 March as an urgent measure. Due to the accident, radionuclides were released into the environment and detected in foodstuff. The Great East Japan Earthquake and tsunami on 11 March 2011 caused the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. In Japan, food regulation measures benefit food safety. Radiation doses (regulated) were significantly less than 1 mSv/year in different FYs. Although estimated doses with or without the reflection of wild vegetables’ intake were similar, estimation that is more plausible is possible, particularly for a high percentile, by reflecting the wild vegetables’ intake. The median, 95th, and 99th percentile of the estimated dose without reflecting the wild vegetables’ intake were 0.0485, 0.183, and 10.6 mSv/year, respectively, in the estimation with all test results (no regulation) and 0.0431, 0.0786, and 0.236 mSv/year, respectively, in the estimation with results within the standard limits (regulated) in FY2012. As a new attempt, dose estimation reflecting the intake of wild vegetables that may have irreplaceable value for local residents was conducted. The effective dose was estimated using the radioactive concentration randomly sampled from the results, food intake, and dose conversion factor. We estimated changes in internal exposure dose using test results. ![]() ![]() Over 2,500,000 monitoring tests were performed under the criteria until fiscal year (FY) 2020. ![]() Focusing on the importance of wild vegetables for local residents, this study aims to validate the effects of food regulations under the current criteria (e.g., 100 Bq/kg for general foods) established approximately a year after the Fukushima Dai-ichi Nuclear Power Plant accident.
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