16 0 0 0 OA 防災指針における飲食物摂取制限指標の改定について
- 著者
- 須賀 新一 市川 龍資
- 出版者
- 日本保健物理学会
- 雑誌
- 保健物理 (ISSN:03676110)
- 巻号頁・発行日
- vol.35, no.4, pp.449-466, 2000 (Released:2010-02-25)
- 参考文献数
- 31
- 被引用文献数
- 8 8
This paper describes the revised index levels of the control of food and water in the Nuclear Safety Commission guidelines, “Off-Site Emergency Planning and Preparedness for Nuclear Power Plants, etc.” Food and water are divided into five categories, and the consumption of each has been conjectured. For this purpose, a nationwide survey for nutrition in Japan by the Welfare Ministry and a survey on the food of infants and children in the coastal area of Ibaraki Prefecture by the National Institute of Radiological Sciences are considered. These categories are (1) drinking water, (2) milk and dairy products, (3) vegetables, (4) grain, and (5) meats, egg, fish, shellfish, and others. The radionuclides groups are then chosen in consideration of their potential importance in regard to food and water contamination. Those chosen were, (1) radio-iodine, (2) radioactive cesium and strontium, (3) uranium, and (4) plutonium and alpha-rayemitting transuranic radionuclides. The intervention dose levels of 5mSv of effective dose and 50mSv of committed equivalent dose to the thyroid for radio-iodine for a period of one year were adopted. The radioactivities of 131I, 132I, 133I, 134I, 135I, and 132Te are assumed to be proportional to the contents in nuclear fuel after a cooling time of 0.5 day, and the radioactivity of 131I is taken as a scale that represents the level of control on the ingestion of food and water. Based on doses to infants, whose exposure is highest, the levels of control are recommended to be 300Bq/kg or more for drinking water and milk and other dairy products, and 2, 000Bq/kg or more for vegetables, except edible roots and potatoes. It is assumed that radio-cesium released in the environment is accompanied by strontium radio-nuclides with a 90Sr/137Cs radioactivity ratio of 0.1, taking into account the past measurements of fallout. Radio-nuclides are assumed to contain 137Cs, 134Cs, 90Sr, and 89Sr with the same mixing ratio as that of the fuel in a nuclear reactor. The sum of radioactivity of 134Cs and 137Cs is used as a scale that represents the level of control, and the yearly average concentration in food and water is presumed equal to half the concentration of those in the peak term. It has then been recommended that the levels of control for radio-cesium should be 200Bq/kg or more for drinking water and milk and other dairy products, and 500Bq/kg or more for vegetables, grain, meat, eggs, and fish. Moreover, in special cases, measurements on radio-strontium are necessary if a nuclear power reactor operates for less than two years because the ratio of 89Sr radioactivity is much higher than in reactors with longer times of operation. For uranium, the index levels are presented in terms of alpha-activity concentration: 20Bq/kg or more for drinking water and milk and other dairy products, and 100Bq/kg or more for vegetables, grain, meat, eggs, and fish. The sum of the radioactivity concentration of 238Pu, 239Pu, 240Pu, 242pu, 241Am, 242Cm, 243Cm, and 244Cm is selected as a scale for representing the levels of control on food and water for plutonium and other transuranic radionuclides. The level of control has been recommended as 1Bq/kg or more for drinking water and milk and other dairy products, and 10Bq/kg or more for vegetables, grain, meat, eggs, and fish. For commercially available food for babies, the recommended level of control is 1Bq/kg or more in a cooked form and served as a meal for plutonium and other transuranic radionuclides.
- 著者
- 千葉 盛人 市川 龍資
- 出版者
- Journal of Radiation Research 編集委員会
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.9, no.1, pp.12-18, 1968-03-01 (Released:2006-08-29)
- 参考文献数
- 17
- 被引用文献数
- 3 4
In view of possible radioactive iodine accumulation by thyroid of breast-fed infant through maternal milk under a certain contaminated environment, the secretion rate of dietary iodine into human milk was estimated by iodine determination for diet and milk. For several hundred μg daily intake level, the secretion rate is around 10 per cent, whereas less than one per cent is found for 10 mg intake level.
2 0 0 0 OA 日本の国民線量―特に外国との比較―
- 著者
- 市川 龍資
- 出版者
- 公益社団法人 日本アイソトープ協会
- 雑誌
- RADIOISOTOPES (ISSN:00338303)
- 巻号頁・発行日
- vol.62, no.12, pp.927-938, 2013 (Released:2013-12-27)
- 参考文献数
- 9
- 被引用文献数
- 4 4
私達は常に種々の原因で放射線を受けている。日本国民が受けている自然及び人工の線源からの被ばく線量は全体で国民1人あたり年間5.98mSvの実効線量と推定された。このうちの大部分を占めるのは,自然放射線の2.1mSv/年と医療被ばく線量の3.87mSv/年の二つである。日本と欧米諸国との国民線量の違いは,日本人のラドンの線量が比較的少ないこと,そして食物からの210Po摂取による体内被ばく線量の大きいことである。その原因は日本人の魚介類摂取量の多いことによっている。魚介類は210Po含有量が多い故である。
