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

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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

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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.

著者

福島 靖正

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.47, no.1, pp.17-19, 2012 (Released:2012-09-06)

被引用文献数

3 6

著者

松永 武 小林 健介

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.36, no.1, pp.31-44, 2001 (Released:2010-02-25)

参考文献数

56

被引用文献数

4

---

The prophylactic use of stable iodine is one of the protective measures during a nuclear emergency. In order to know the resultant radiation dose to the thyroid gland and the effectiveness of iodine prophylaxis in the case of Japanese, a sensitivity analysis was performed for related physiological parameters for Japanese. As a result, the variances in the deposition efficiency of radioactive iodine aerosol in the respiratory tract due to changes in the respiratory parameters were found rather small between the standard Caucasian and Japanese. The changes due to the radioactive iodine aerosol size were more significant, suggesting the importance of understanding the physico-chemical status of aerobic radioiodine released in a nuclear emergency. Concerning the metabolic parameters of iodine, the result of the sensitivity analysis based on an iodine metabolic model showed that the most critical parameters are those which describe the transport of stable and radioactive iodine from the blood compartment to the thyroid gland. Accordingly, a confirmation of the transport model and the related parameters for Japanese are essential to clarify the effectiveness of iodine prophylaxis to reduce thyroid gland exposure of Japanese. (This work was performed under the auspices of the Science and Technology Agency of Japan.)

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

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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

渡邉 正己

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.47, no.2, pp.118-123, 2012 (Released:2012-12-07)

参考文献数

15

---

It has been believed that the first target of radiation carcinogenesis is DNA. However, this is not proved for radiation carcinogenesis yet. We discovered that frequency of aneuploid cell was closely related to that of radiation-induced cell transformation and natural cell transformation by high-density cultivation, but gene mutation was not. Cell with p53 gene becomes tetraploid, but does not get tumorigenicity. On the other hand, cells without p53 gene function become a triploid easily, and acquire tumorigenicity. Both radiation exposure and high-density cultivation elevated the level of intracellular oxidative radicals. These radicals induced centrosome destabilization and produced cells carrying extra centrosome, which promote merotelic attachment of chromosome by altering spindle geometry. Unresolved merotelic attachments can give rise to lagging chromosomes at anaphase. Aneuploidy was seen in high frequency in early process of cell transformation. These results strongly suggest that a main target of carcinogenesis by low dose radiation is not DNA, but is centrosome, which are the proteins to constitute chromosomal homeostasis maintenance mechanism. In addition, this route may be the same as that of natural carcinogenesis. These serial results support necessity of a review of a LNT hypothesis at a radioprotective point of view.

著者

中村 典

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.2, pp.217-223, 2000 (Released:2010-02-25)

参考文献数

14

被引用文献数

1

著者

Noriko KOBAYASHI

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.54, no.1, pp.55-65, 2019-04-18 (Released:2019-09-03)

参考文献数

20

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The International Commission on Radiological Protection (ICRP) internal dose assessment model, currently adopted in Japanese regulation, assumes uniform distribution of radionuclides in bone marrow blood (ICRP Publication 60). Recent studies have revealed a localization of hematopoietic stem cells (HSCs) and immune cells in the perivascular region of the bone marrow sinusoids, suggesting a need to consider nonuniform distributions of the blood source and HSCs. To evaluate energy transfer to HSCs, a simplified model of cervical vertebrae with bone tissues and blood vessels was built using data from the adult Japanese male phantom. Doses absorbed by HSCs from blood and hard bone sources were calculated using a Monte Carlo simulation, and absorbed fractions (AFs) and specific absorbed fractions (SAFs) from electrons were compared with those in the ICRP 1990 model. In the cervical vascular model, electron SAFs from sinusoidal blood in the red bone marrow (RBM) to the target perivascular region were 1.2 to 6.9 times higher than the SAF in the ICRP 1990 model, suggesting an underestimation of the RBM dose. Electrons from the cortical bone source to the perisinusoidal target exhibited energy transfer. The ICRP 1990 model underestimates electron SAFs from radionuclides in sinusoidal blood and cortical bones. A more elaborate model is needed to examine doses for the RBM and effects on hematopoietic and immune functions.

著者

武田 洋

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.23, no.4, pp.331-342, 1988 (Released:2010-02-25)

参考文献数

29

著者

脇田 宏

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.31, no.2, pp.215-222, 1996 (Released:2010-02-25)

参考文献数

15

被引用文献数

3 4

著者

草間 朋子 中川 健朗 吉澤 康雄

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.20, no.4, pp.399-406, 1985 (Released:2010-02-25)

参考文献数

24

被引用文献数

1

---

The concept of population dose is of importance and of interest at the point of radiation protection of puplic. We devided it into two categories, source-related population dose and individual-related population dose, and estimated each population dose of Japan. We surveyed all sources that caused exposure to Japanese population. A number of sources, both naturally-occuring and man-made, contributed to population exposure. According to source-related dose assessment, average annual effective dose equivalent was about 3.3mSv, and about half of which, i. e. 1.6mSv, was given from medical exposure. And from the results of individual-related dose assessment we proposed the allocation of the annual dose limit of public for each controllable source, that is, 2.5mSv/yr to nuclear faculties, 1.0mSv/yr to miscellaneous sources, 1.5mSv/yr to probablistic exposure.

著者

土屋 武彦 法村 俊之 山本 久夫 畠山 智

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.20, no.3, pp.279-284, 1985 (Released:2010-02-25)

参考文献数

10

被引用文献数

2 1

---

The radiations emitted from the front surface of CRT of a color-television and a personal-computer display were measured by GM-counter. No difference was observed in the radiation dose between the cases with and without application of a high voltage to the CRT. The radiations were also measured by Si- and Ge-semiconductor spectrometers. It was found that the radiations emitted from CRT were composed of β- and γ-rays, and were essentially emitted from 40K and the nuclides of uranium- and thorium- series contained within the front glass of CRT. The exposure dose rate of these radiations at 50cm from the surface of CRT was, however, less than 1.6×10-3mrem/hr, and it was practically negligible in comparison with that of natural background radiations.

著者

Jacques LOCHARD Ryoko ANDO Hiroshi TAKAGI Shinya ENDO Maiko MOMMA Makoto MIYAZAKI Yujiro KURODA Takeshi KUSUMOTO Masako ENDO Setsuko ENDO Yohei KOYAMA

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.56, no.1, pp.39-52, 2021-03-31 (Released:2021-05-26)

参考文献数

26

著者

藤原 慶子 山崎 敬三 高橋 知之 高橋 千太郎 北川 晃三 神藤 克人

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.47, no.4, pp.282-285, 2012 (Released:2013-12-17)

参考文献数

8

被引用文献数

1

---

After the Fukushima Daiichi Nuclear Power Plant Accident, many people are concerned about the contamination of radioactive substances in their ordinary surrounding environment. In this study, we determined the levels of radioactive contamination with 137Cs in towels, very common textile products in our life, after exposing those to the soil collected from a farm field near Fukushima city. Three kinds of towels made from the same cotton fiber with different thickness were exposed to the soil under dry or water-suspension conditions. The radioactivities of 137Cs retained/absorbed were 30-50% of the loaded radioactivity per gram weight of the towel. When their weight and absorbency are taken into consideration, the differences in thickness did not so much affect the above values. Under standard washing condition, which mimic those with household washing machine, almost all the radioactive cesium were removed from the towels contaminated under the dry conditions, whereas only 50-70% were removed when the towels were contaminated under the wet conditions. A commercial soil-release treatment (Preshade-SR) didn't reduce the contamination under both dry and wet conditions, although processing the towels with silver nano-particles did.

著者

渡部 輝久

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.41, no.4, pp.221-233, 2006 (Released:2010-08-05)

参考文献数

25

---

Environmental protection is one of the key issues in the prospective policy and strategy of radiation protection. In this context, numerous efforts have been made for developing the framework for the protection of non-human species from ionizing radiation, especially in European countries and Unite States. The present report summarizes knowledge so far attained on the assessment of doses and radiation impact on marine organisms. Special attention was directed to the methodology for calculating absorbed doses of marine organisms, based on which a case study was also carried out for estimating absorbed dose rate of several species of marine organisms inhabiting in the coastal sea off Rokkasho-Mura, Aomori Prefecture where a spent nuclear fuel reprocessing plant came into operation.

著者

小池 弘美 甲斐 倫明 飯本 武志

出版者

一般社団法人日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.57, no.3, pp.140-145, 2022-12-29 (Released:2023-02-09)

参考文献数

16

---

Relatively high levels of radioactivity were detected from the handball goal post that had been placed in the schoolyard of an elementary school in Nobeoka City, Miyazaki Prefecture, since around 1997. In November 2021, the goal post was to be removed, and it was transferred to a scrapping company through a waste disposer commissioned by Nobeoka City. Radiation monitoring at the time of transport detected the surface dose rates of 20–30 μSv/h at maximum from the pipe scale of the goal post. The goal post was found to have been apparently handmade by reusing scrap metal pipes. The components and radioactivity adhering to the interior of the pipe are measured and analyzed. Mineralogical analysis shows that the naturally occurring radioactive materials (NORM) contained mainly gypsum, gorgeyite, and baryte. The total radioactivity was evaluated to be 54.5 MBq to be equivalent to 226Ra by a preliminary estimation. The specific activity of the collected sample was 0.6 MBq/kg in the same nuclide. This case may be one of the typical examples of NORM in Japan, and four points in terms of radiation protection are discussed, clarification of the scientific and technical mechanisms of NORM generation, formulation of systematic and specific guidelines on the estimation of NORM according to the purpose of the evaluation, formulation of a comprehensive radiation protection strategy for NORM in Japan, and clarification of policies and procedures on sharing and disseminating relevant information to the public.

著者

岩倉 哲男

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.10, no.3, pp.131-140, 1975 (Released:2010-02-25)

参考文献数

28

---

An attempt is made to review behavior of tritium released into the environment in order to give preliminary knowledges for monitoring present and future levels of tritium in the environment. A systematic distribution of bomb-produced tritium on a global scale has been recognized from an evaluation of the precipitation data conducted by the IAEA-WMO Precipitation Network Survey. Latitudinal dependence and continental effect of the tritium concentration in precipitation were found pronouncedly. The mean residence times of several compartments of hydrological cycle for tritiumm are discussed topically. Recent tritium concentration in environmental water in Japan are summarized. Organically bound tritium in sediments, aquatic plants, fish, and foodstaffs sometimes showed higher concentration than tritium in ambient water. This is probably explained as memory effect or inheritance effect through eco-systems due to long residence time of organically bound tritium. Instrumentation, detection limit and dose calculation for tritium monitoring are proposed. Tritium surveillance activities conducted by U. S. Government are reviewed also historically with some representative data.

著者

吉澤 道夫 辻村 憲雄

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.36, no.1, pp.18-23, 2001 (Released:2010-02-25)

参考文献数

8

被引用文献数

1

著者

谷川 攻一

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.2, pp.45-46, 2018 (Released:2018-09-13)

参考文献数

2

被引用文献数

1

著者

森内 茂 堤 正博 斎藤 公明

出版者

Japan Health Physics Society

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.25, no.2, pp.121-128, 1990 (Released:2010-02-25)

参考文献数

13

被引用文献数

21 26

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A practical conversion factor to estimate the value of effective dose equivalent rate in Sv unit from absorbed dose rate in air in Gy unit was examined for natural gamma radiations. The experimental examination was carried out by two methods; one measures the effective dose equivalent rate directly by using a measuring instrument having effective dose equivalent response for isotropic gamma radiations and the other obtaines it from calculation applying the gamma flux-to-effective dose equivalent factor to actual gamma energy spectrum measured in various indoor and outdoor places.From these investigations the value of the quotient of effective dose equivalent to absorbed dose in air was found do be 0.748±0.007 Sv per Gy for natural radiation exposures in various environments. The value of the quotient 0.7, which is adopted to applied to environmental gamma radiations in the UNSCEAR 1982 and 1988 Reports, was clarified to be about 7% lower than the one obtained experimentally for natural gamma radiations.