Contents and Daily Intakes of Gamma-Ray Emitting Nuclides, 90Sr, and 238U using Market-Basket Studies in Japan

Abstract

To investigate the contents of radionuclides in foods marketed in Japan and their daily intakes and exposure doses in adults, we performed market-basket studies concerning radionuclide intakes. The study period was [2003][2004][2005], and the studies were performed in 13 cities in Japan. Foods including drinking water were divided into 14 food groups, and samples were prepared by common cooking procedures. γ-ray emitting nuclides (an artificial radionuclide, radioactive Cs, and natural radionuclides, 40 K and U series such as 214 Bi, and 212 Pb, and Th series) were measured in each food group, and artificial radionuclides, 90 Sr and 238 U, were measured in a mixed sample of 13 food groups excluding drinking water. The daily intakes in adults were calculated from the concentrations of the radionuclides and mean daily consumption of foods and drinking water. The daily 137 Cs and 40 K intakes (mBq/ person · day) in the 13 cities were 12.5-<79.7 and 57309-95746, respectively. The 90 Sr intake from the food groups excluding drinking water was 20.8-53.6, with a mean of 39.2 (mBq/person · day) (deviation of the mean: 23%). Similarly, the daily 238 U intake was 5.9-31.1, with a mean of 12.6 (mBq/person · day) (deviation: 60%), showing a more than 5-fold difference between the minimum and maximum values, and there were regional differences. Since the contents of the U series, such as 214 Bi and 212 Pb, and Th series were lower than the lower detection limits in many samples, their daily intakes were not calculated. Regarding the daily intake of 137 Cs from each food group, the intakes from fish and shellfish, milk, meat/eggs, and mushrooms/seaweed tended to be higher. The daily 40 K intake from each food group varied among the areas, but the total intake from the 14 food groups was similar in all 13 cities. 40 K from these foods accounted for most of the annual effective dose (µSv/person · year) of γ-ray emitting nuclides, and the doses of 40 K, 90 Sr, and 238 U were 130-217, 0.21-0.55, and 0.10-0.51, respectively.Key words --radionuclide, intake, dose estimation, diet, cesium INTRODUCTIONClarification of the contents and distribution of toxic substances in foods, and estimation and evaluation of their intakes by the public are important to secure food safety. For this purpose, studies concerning dietary intakes of chemical substances, such as Polychlorinated Biphenyl (PCB) and dioxin, and toxic elements, such as Cd, Pb, and As, have been * To whom correspondence should be addressed: Department of Environmental Health, National Institute of Public Health, 2-3-6, Minami, Wako-shi, Saitama 351-0197, Japan. Tel.: +81-48-458-6263; Fax: +81-48-458-6270; E-mail: sugiyama@niph.go.jp performed in Japan. [1][2][3][4] In addition to these substances, it is important to investigate the intakes of radionuclides, considering them to be toxic substances, and evaluate the dietary exposure doses based on the values obtained. Studies concerning the daily intakes of radionuclides by the public have been performed in many countries, [5]...

Continuous Estimation of Annual Committed Effective Dose of Radioactive Cesium by Market Basket Study in Japan from 2013 to 2019 after Fukushima Daiichi Nuclear Power Plant Accident

“…The detection rate for 137 Cs in categories 2, 10, 11, and 12 was over 50% in most cases throughout this study, especially in category 10, which consisted of fishes and shellfishes and had a detection rate of more than 90%. A similar tendency was reported in a study conducted by Sugiyama et al 23) before the FDNPP accident. This suggests that although the influence of global fallout and the Chernobyl nuclear accident remained in all food categories, their influence on category 10 was severer than other food categories.…”

“…Daily intake of 137 Cs in Japan before the FDNPP accident was reported by Sugiyama et al in 2007 23) . According to previous data, daily intake of 137 Cs in 13 cities in Japan (Sapporo, Sendai, Saitama, Chiba, Yokohama, Niigata, Nagoya, Osaka, Kobe, Yamaguchi, Takamatsu, Fukuoka, and Naha) ranged from 0.012 to 0.042 Bq/day (calculated from only quantifiable values, which means that ND was handled as 0) and <0.038 to <0.080 Bq/day (calculated by assuming that concentrations less than the LODs were equal to the LODs, which means that ND was handled as the LOD), respectively.…”

Estimated Dietary Intake of Radionuclides and Health Risks for the Citizens of Fukushima City, Tokyo, and Osaka after the 2011 Nuclear Accident

“…The 95th percentile effective doses due to total radionuclides were 110 µSv in Fukushima City (Case 1), 530 µSv in Fukushima City (Case 2), 80 µSv in Tokyo, and 7.1 µSv in Osaka, 2 to 3 times the average values (Table 2). These values were much lower than the annual effective dose due to other natural radionuclides in the diet; e.g., potassium 40 ( 40 K), 130–217 µSv [68]; polonium 210 ( 210 Po), 730 µSv [69]. The provisional limits of radionuclides in drinking water and foods, which were announced by the Japanese government just after the accident, were determined from the intervention levels of 50 000 µSv of an annual thyroid equivalent dose due to 131 I and 5000 µSv of an annual effective dose due to 134 Cs, 137 Cs, 89 Sr, and 90 Sr [22].…”

Evaluation of Cesium-137 (137Cs) and Elements Intake from Daily Diets in Residents of Kanagawa Prefecture, Japan

“…The daily dietary 137 Cs level recorded in Kanagawa Prefecture in recent years was close to the level of 137 Cs contained in the total diet samples collected in Japan by Sugiyama et al using the market basket method (0.012-< 0.077 Bq day −1 ). 9) In the Hiratsuka area, the mean 137 Cs intake was 0.080 ± 0.056 Bq man −1 day −1 , with a median of 0.065 Bq man −1 day −1 .…”