著者
永岡 美佳 藤田 博喜 中野 政尚 渡辺 均 住谷 秀一
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.48, no.2, pp.104-113, 2013 (Released:2014-03-06)
参考文献数
25
被引用文献数
1 3

Monthly deposition samples were collected at the Nuclear Fuel Cycle Engineering Laboratories located about 115 km south of the Fukushima Daiichi Nuclear Power Plant (NPP), and the radioactive nuclides were analyzed. Although radionuclides such as 131I, 129mTe-129Te and 132Te-132I with 134Cs and 137Cs were observed by gamma spectrometry at the early time of the Fukushima Daiichi NPP accident, only 134Cs and 137Cs were detected as of September 2011. The annual depositions of 134Cs and 137Cs were about 19,000 and 17,000 Bq m-2, respectively in March 2011-February 2012 after the accident. Moreover, 90Sr was detected in some samples. Monthly 90Sr deposition in March 2011 was 5.1 Bq m-2 month-1 and then decreased after that. On the other hand, 239, 240Pu concentration was the same level with the concentration before the accident.
著者
藤原 慶子 高橋 知之 高橋 千太郎
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.51, no.1, pp.19-26, 2016 (Released:2016-07-06)
参考文献数
11
被引用文献数
3

The accident at the Fukushima nuclear power plant in 2011 caused the release of large amounts of tellurium (Te) isotopes, with radio-cesium (Cs) and radio-iodine (I), into the environment. The total amounts of 127mTe and 129mTe released from the nuclear power plant were estimated as 1.1 × 1015 and 3.3 × 1015 Bq, respectively. At the location where the deposition of 129mTe was relatively large, the ratio of the radioactivity of 129mTe to that of 137Cs reportedly reached 1.49 on June 14, 2011. Since 127mTe has a relatively long half-life, it possibly contributed to the internal radiation dose at the early stage after the accident. In this paper, the ratio of the committed effective dose of 127mTe to that of 137Cs after the oral ingestion of rice was estimated by using various reported parameters. The relevant parameters are: 1) the deposition ratios of 127mTe, 129mTe, and 134Cs to 137Cs; 2) the deposition ratio of 127mTe to 129mTe; 3) the transfer factors of Te and Cs; and 4) the effective dose coefficients for 127mTe, 129mTe, 134Cs, and 137Cs. The ratios of the committed effective dose of 127mTe to that of 137Cs were calculated for adults after a single ingestion at the time of the rice harvest. The ratio was 0.45 where the 129mTe/137Cs in the soil was higher and 0.05 where the level of 129mTe/137Cs was average. The ratio of the committed effective dose from 129mTe and 127mTe to that from 137Cs for one year reached 0.55 and 9.03 at the location where the level of 129mTe/137Cs in the soil was higher. These data could indicate that radioactive Te should not be disregarded in reconstructing the internal radiation dose from food for one year after the accident.
著者
浜田 信行 ロイ E. ショア ローレンス T. ダウアー
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.53, no.2, pp.47-64, 2018 (Released:2018-09-13)
参考文献数
60
被引用文献数
2 3

For over four decades, a linear nonthreshold (LNT) model has been used for radiation protection purposes. In the United States of America, the National Council on Radiation Protection and Measurements (NCRP) established Scientific Committee 1-25 in 2015 to prepare a commentary to review recent epidemiologic data from studies with low doses or low dose rates and from the Life Span Study of atomic-bomb survivors to determine whether these epidemiologic studies broadly support the LNT model. In May 2018, NCRP published Commentary No. 27 “Implications of recent epidemiologic studies for the linear nonthreshold model and radiation protection”, noting that the ongoing development of science requires a constant reassessment of prior and emerging evidence to assure that the approach to radiation protection is optimal, even if not necessarily perfect. Based on the current epidemiological data, NCRP concluded that the LNT model (perhaps with excess risk estimates reduced by a dose and dose rate effectiveness factor) should continue to be utilized for radiation protection purposes. The Commentary will be used to support the work of NCRP Council Committee 1 who are charged to develop current radiation protection guidance for the United States, ultimately updating and expanding the basic radiation protection recommendations of NCRP Report No. 116 published in 1993. This review provides an outline and summary of the key points of NCRP Commentary No. 27.
著者
飽本 一裕
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.49, no.1, pp.17-28, 2014 (Released:2015-02-26)
参考文献数
49
被引用文献数
1 2

In this report, several works on mainly resuspension and eolian transfer of radioactive cesium due to wind, which is one of the most effective transfer processes of previously deposited radioactive particulate materials, are introduced. First, the mechanisms of the resuspension of particulate matter by wind as well as resultant dust storms and wind erosion are surveyed. Next, the papers related to resuspension and eolian transfer of radioactive aerosols originally emitted by the Chernobyl nuclear accident are reviewed. The measured fallouts and radioactivity concentrations show annual cycles, and their peak periods depend on the measured regions. Finally, the works that analyze the related effects of the accident at the Fukushima Daiich Nuclear Power Plant are reviewed, and some issues to be focused and resolved are summarized.
著者
堀 雅明 中井 斌
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.11, no.1, pp.1-11, 1976 (Released:2010-02-25)
参考文献数
37
被引用文献数
1 1

Genetic risk assessment for potential hazard from environmental tritium to man becomes important with increasing nuclear-power industry. The purpose of this short review is to discuss the possible genetic effects of tritium from a view of genetic risk estimation.The discussion is based mainly on our experimental results on the chromosome aberrations induced in human lymphocytes by tritium at the very low-level. The types of chromosome aberrations induced by radiation from tritium incorporated into the cells are mostly chromatid types. The most interesting finding is that the dose-response relationship observed in both tritiated-water and tritiated-thymidine is composed of two phases. The examination on the nature of two-phase dose-response relationship is very important not only for the mechanisms of chromosome aberrations, but also for the evaluation of genetic risk from low-level radiation.
著者
田中 俊一
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.53, no.3, pp.133-134, 2018 (Released:2018-11-27)
著者
中野 政尚 國分 祐司 武石 稔
出版者
日本保健物理学会
雑誌
保健物理 : hoken buturi (ISSN:03676110)
巻号頁・発行日
vol.44, no.1, pp.60-65, 2009-03
被引用文献数
3

The tritium concentrations in seawater collected around the Tokai Reprpcessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of expected diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.
著者
中野 政尚 國分 祐司 武石 稔
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.44, no.1, pp.60-65, 2009 (Released:2010-10-08)
参考文献数
15
被引用文献数
3

The tritium concentrations in seawater collected around the Tokai Reprpcessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of expected diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.
著者
工藤 伸一 石田 淳一 吉本 恵子 水野 正一 大島 澄男 古田 裕繁 笠置 文善
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.51, no.1, pp.12-18, 2016 (Released:2016-07-06)
参考文献数
16
被引用文献数
7

Radiation Effects Association has carried out radiation epidemiological study for nuclear industry workers during 1990-2010. We assembled a cohort of 204,103 workers. The average cumulative dose was 13.8 mSv (median 1.0 mSv, interquartile range (IQR) 0.0-10.7 mSv) and the average follow-up period was 14.2 year. The present report has not concluded that low-dose radiation increases cancer mortality based on the follow-up data through 2010. One reason is that analyses among 75,442 respondents― the average cumulative dose was 25.8 mSv (median 6.3 mSv, IQR 0.2-28.0 mSv) and the average follow-up period was 8.3 year―to the lifestyle surveys revealed the decrease of the ERR after adjusting for smoking habits or educational year, suggesting that confounder has a large effect on the association between radiation exposure and mortalities in the cohort. Another reason is that in analyses on all cohort members, no significant ERR was observed in all death, and leukemia excluding chronic lymphoid leukemia. Significant ERR was seen in all cancers excluding leukemia, but this significance of the ERR might be affected by confounder such as smoking, because the significance of the ERR in all cancers excluding leukemia originates in the significance of the ERR in lung cancer.
著者
加藤 秀起 古賀 佑彦 向山 隆史 戸松 弘孝 鈴木 友輔 鈴木 昇一
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.44, no.4, pp.380-386, 2009 (Released:2011-01-12)
参考文献数
7
被引用文献数
3

In one of the accidents that might happen in the nuclear power station, there is a contamination accident caused by radioactive corrosion products during a periodic inspection. It is necessary to presume the skin absorbed dose from the adhesion area and the contamination density to forecast the level of the skin hazard by the adhesion of the radioactive substance. However, the data to forecast the local skin dose when the radioactive substance adhered handily is not maintained. In this paper, the absorbed dose in the skin surface neighborhood contaminated by radioactive corrosion products was calculated, and the relation between the adhesion area and the contamination density and the local absorption dose was derived. And, the approximate equation that forecast the integrated dose was derived from these data. As for the absorbed dose rate in depth 70 μm from the skin surface that became the index of the skin hazard, the contribution rate by 59Fe was the highest within 30 days, and the contribution of 60Co rose most after the 30th after the radioactive substance had adhered when the contamination density the adhesion area was the same. The relation between the initial contamination density and days that required it was graphed to reaching to the threshold by the integrated dose when the threshold dose in which the necrosis of the skin was caused was assumed to be 20 Gy. The absorbed dose commitment can be presumed from measurements of the contamination density by using this graph or the approximate equation.
著者
横山 直方
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.30, no.3, pp.243-250, 1995 (Released:2010-02-25)
参考文献数
18
著者
鈴木 元
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.1, pp.4-11, 2000 (Released:2010-02-25)
被引用文献数
2
著者
甲斐 倫明
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.18, no.1, pp.3-10, 1983 (Released:2010-02-25)
参考文献数
36
被引用文献数
1 4 3

The purpose of the present study was to estimate a biological half-life of iodine in normal Japanese thyroid for the calculation of the thyroid dose from iodine-129 with a long physical half-life. The Japanese takes stable iodine through sea food in a more considerable amount than the Caucasian who is assumed to be the Reference Man recommended by ICRP. It can be shown by medical research in thyroidology that the iodine metabolism between the Japanese and the Caucasian is different owing to the amount of the ingested stable iodine. Furthermore, in the Japanese the thyroid releases inorganic iodine since it takes up iodine more than physiologically required to produce thyroid hormone.We calculated the biological half-life of iodine for both the Japanese and the Caucasian by using a five compartment model. The following results were delivered. The biological half-life in the Japanese was approximately 40 days, which was in agreement with the values reported before. On the other hand, that of the Caucasian was 130 days nearly equal to the Reference Man.
著者
河合 広 本田 嘉秀 森嶋 弥重 古賀 妙子 木村 雄一郎 西脇 安
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.3, no.2, pp.273-279, 1968 (Released:2010-03-15)
参考文献数
13

We have observed properties of radioactive fallout originated from the first, the second, the third, the fourth and the fifth Chinese nuclear explosions. The differences in gross beta-activities, activities per unit volume and their particle sizes of highly radioactive particles are discussed with relation to the differences in burst conditions among the five explosions from which they originated.It was found that radioactivities of the highly radioactive particles were roughly proportional to their volumes. The differences in the radioactive decay rates of highly radioactive fallout particles were found in connection with their colors.From the results of decay characteristics of gross beta-activities and γ-ray spectra of fallout samples, it was found that the contribution of radioactivities of 239Np in samples from the fifth Chinese explosion was larger than that from the third Chinese explosion.In comparison between the γ-ray spectra of highly radioactive fallout particles from the third and the fifth Chinese explosions, the particles from the third Chinese explosion were enriched in 95Zr+95Nb and impoverished in 103Ru, while on the particles from the fifth Chinese explosion, the reverse of phenomenon above mentioned was observed.
著者
石川 徹夫 安岡 由美 長濱 裕幸 川田 祐介 大森 康孝 床次 眞司 志野木 正樹
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.43, no.3, pp.253-267, 2008 (Released:2010-08-05)
参考文献数
70
被引用文献数
2 3

Before the 1995 Hyogoken-Nanbu earthquake, various geochemical precursors were observed in the aftershock area: chloride ion concentration, groundwater discharge rate, groundwater radon concentration and so on. Kobe Pharmaceutical University (KPU) is located about 25km northeast from the epicenter and within the aftershock area. Atmospheric radon concentration had been continuously measured from 1984 at KPU, using a flow-type ionization chamber. The radon concentration data were analyzed using the smoothed residual values which represent the daily minimum of radon concentration with the exclusion of normalized seasonal variation. The radon concentration (smoothed residual values) demonstrated an upward trend about two months before the Hyogoken-Nanbu earthquake. The trend can be well fitted to a log-periodic model related to earthquake fault dynamics. As a result of model fitting, a critical point was calculated to be between 13 and 27 January 1995, which was in good agreement with the occurrence date of earthquake (17 January 1995). The mechanism of radon anomaly before earthquakes is not fully understood. However, it might be possible to detect atmospheric radon anomaly as a precursor before a large earthquake, if (1) the measurement is conducted near the earthquake fault, (2) the monitoring station is located on granite (radon-rich) areas, and (3) the measurement is conducted for more than several years before the earthquake to obtain background data.