著者

川口 勇生

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.55, no.1, pp.23-31, 2020-04-01 (Released:2020-05-21)

参考文献数

43

---

An international framework for environmental radiation protection has been developed over the last few decades. From 2005 to 2017, the International Commission on Radiological Protection (ICRP) established a committee on environmental protection and published several reports. ICRP developed a protection framework which was based on the Reference Animals and Plants corresponding to the Reference Man in radiation protection of humans, and the Derived Consideration Reference Level which is the band of dose rates corresponding to the possibility of adverse effect of each animals and plants. The present review summarized the current state of the environmental protection system focusing on the activities of ICRP first and then of other international organizations. The current issues about environmental protection were also discussed.

著者

清水 翔太 荒川 弘之 本田 城二 徳森 謙二 藤淵 俊王

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.4, pp.315-323, 2021-12-28 (Released:2022-03-01)

参考文献数

24

---

Clear radiation protection training and explanation tools for medical staff, patients, and caregivers during radiography are required. In this study, we developed visualization tool of scattered radiation distribution image of each X-ray room conditions. The 400 cases of X-ray room conditions were simulated using a Monte Carlo simulation code, Particle and Heavy Ion Transport code System (PHITS). The simulation conditions were (i) width and depth of the X-ray room (200 cm, 250 cm, 300 cm, 400 cm and 500 cm), (ii) opening or closing of the sliding door, (iii) direction of the X-ray table, (iv) X-ray posture, and (v) with or without protective clothing/shield. The scattered radiation distribution images were published on the Internet. The images are easily accessible on the Internet with selecting each radiography room condition. In radiation protection education, our tool can be used to (a) reduce radiation dose by keeping away from X-ray sources and scattered radiation sources, (b) shield scattered radiation by protective clothing and protective screens, and (c) prevent leakage of scattered radiation outside the room by closing the door of the radiography room. Our tool would improve the efficiency of radiation protection training for medical staff and alerting to patients and caregivers.

著者

Miroslaw JANIK

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.52, no.2, pp.114-121, 2017 (Released:2017-07-29)

参考文献数

64

被引用文献数

5 10

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Indoor radon and thoron concentration measurements have been intensively carried out since the 1980s for assessment of radiation doses to workers and the general public. For example, the European Union countries established reference levels for indoor radon concentration in relation to national action plans to address long-term risk from radon exposures. Measurements done using a reliable method are the only way to investigate radon concentration levels. In order to ensure the quality of measurements, intercomparisons among laboratories are performed, as one verification method. The primary purpose of this paper is to provide a concise review of intercomparisons of radon and thoron monitors carried out by four institutions: NIRS (Japan), PHE (UK), BfS (Germany) and SURO (Czech Republic). The different measurement set-ups, evaluation methods and statistical treatments utilized by those institutions are described.

著者

藤通 有希 小佐古 敏荘 吉田 和生 浜田 信行

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.97-103, 2013 (Released:2014-03-06)

参考文献数

25

被引用文献数

2 1 1

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Radiation cataract has been classified as tissue reactions (formerly known as deterministic effects or non-stochastic effects) with a threshold dose. In 1984, the International Commission on Radiological Protection (ICRP) suggested the threshold dose of >8 Sv for vision-impairing cataracts in highly fractionated or protracted exposures. Such a threshold was used to recommend an occupational dose limit for the lens of 150 mSv/year in 1990 and 2007, but was reduced to 0.5 Sv in 2011 for all exposure scenarios irrespective of the rate of dose delivery. New threshold was determined on the basis of the limited human evidence, with various hypotheses not supported by the present knowledge of biological mechanisms. Examples of untested hypotheses include: (a) radiation cataract is a tissue reaction; (b) radiation damage to the large number of cells acts as a triggering event for radiation cataract; (c) detectable minor opacities progress into vision-impairing cataracts with time; and (d) the lower the dose, the longer the latency. This paper discusses the issues behind the scientific basis for the new threshold, and provides directions for future epidemiological and biological studies to establish the reasonably modeled dose-response relationship for radiation cataract.

著者

栗原 千絵子

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.54, no.1, pp.19-28, 2019-04-18 (Released:2019-09-03)

参考文献数

26

被引用文献数

2

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The International Commission on Radiological Protection (ICRP) issued in February 2018 the Publication 138, titled “Ethical foundation of radiological protection system.” Although the ICRP has longtime recognized that ethics is an essential component of their radiological protection system, they have rarely described explicitly about the ethical foundation of the system. For this reason, the Commission established in 2012 the task group 94 to clarify and describe the ethical foundation of the system. As the result, the publication shows the process of evolution of the radiological protection system through 20th century until now, which leads to the identification of four core ethical values underpinning the system: beneficence and non-maleficence; prudence; justice; and dignity, along with related procedural values: accountability; transparency; and inclusiveness (stakeholder participation). As one of the authors of this publication, I will briefly introduce the developing process and the outlines of it, and additionally will provide a short summary of my experience of discussion through the workshops worldwide, concerning the nuclear accident of the Fukushima Daiichi Nuclear Power Station, as well as commonalities and diversities of Western and Asian perspectives of ethical core values.

著者

青山 隆彦 小山 修司 川浦 稚代 杉本 成人 藤井 啓輔 瀬口 繁信 川崎 稔生

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.270-281, 2012 (Released:2013-12-17)

参考文献数

17

被引用文献数

1

---

Data are presented on radiation doses to infant, child and adult patients undergoing head, chest and abdominal CT examinations with recent multi-detector row CT scanners (MDCT). Also presented are dose data in CT coronary angiography(CTCA) observed with Toshiba 320MDCT and Siemens 64MDCT. The doses were measured using newborn, 6-year-child and adult anthropomorphic phantoms, in which photodiode dosimeters were implanted at various tissue and organ positions. Measured doses were used to evaluate organ and effective doses. Organ doses in the scan region obtained in head CT were 20-40 mGy for infants and children, and 40-70 mGy for adults. Effective doses in head CT were 2.1-3.3 mSv for infants,and 1.0-2.0 mSv for children and adults. These doses in chest CT were 3-9 mGy and 2-6 mSv for infants, 2-12 mGy and 1-7 mSv for children, and 5-35 mGy and 7-14 mSv for adults. In abdominal CT they were 3-14 mGy and 2-10 mSv for infants, 4-18 mGy and 3-12 mSv for children, and 10-48 mGy and 9-21 mSv for adults. In CTCA radiation doses for helicalscan without using dose modulation were reduced to less than 1/6 and 1/10 by using prospectively gated axial scan of Toshiba320MDCT and “Flash Spiral” scan of Siemens 64MDCT, respectively.

著者

篠原 邦彦 大内 浩子 近本 一彦 谷口 和史 永井 博行 森本 恵理子 米澤 理加 渡辺 浩

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.374-379, 2009 (Released:2011-01-12)

参考文献数

19

被引用文献数

1 2

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In the field of atomic energy and radiation utilization, radiation risk is considered as one of the social uneasy factors. About the perception of risks, there is a gap between experts and general public (non-experts). It is said that the general public tends to be going to judge risk from intuitive fear and a visible concrete instance whereas the experts judge it scientifically. A company, an administration or experts should disclose relating information about the risks and communicate interactively with the stakeholders to find the way to solve the problem with thinking together. This process is called “risk communication”. The role of the expert is important on enforcement of risk communication. They should be required to explain the information on the risks with plain words to help stakeholders understand the risks properly. The Japan Health Physics Society (JHPS) is the largest academic society for radiation protection professionals in Japan, and one of its missions is supposed to convey accurate and trustworthy information about the radiation risk to the general public. The expert group on risk communication of ionizing radiation of the JHPS has worked for the purpose of summarizing the fundamental matters on radiation risk communication. “Lecture on risk communication for the members of the JHPS.” which has been up on the JHPS web-site, and the symposium of “For better understanding of radiation risk.” are a part of the activities. The expert group proposes that the JHPS should enlighten the members continuously for being interested in and practicing risk communication of radiation.

著者

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.54, no.4, pp.205, 2019-12-27 (Released:2020-01-31)

参考文献数

1

著者

Jean-François LECOMTE Amber BANNON Yann BILLARAND Peter BRYANT Marie-Claire CANTONE Roger COATES John CROFT Stéphane JEAN-FRANÇOIS Bernard Le GUEN Caroline SCHIEBER Thierry SCHNEIDER

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.54, no.3, pp.188-194, 2019-10-29 (Released:2019-11-21)

参考文献数

8

著者

松原 孝祐 Thunyarat CHUSIN 大久保 玲奈 小川 善紀

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.4, pp.238-246, 2018 (Released:2019-03-03)

参考文献数

39

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Evaluation of radiation dose from medical exposure is important because the use of ionizing radiation in medical field contributes significantly to the exposure of the population. In plain radiography, the entrance skin dose, which is absorbed by the skin as it reaches the patient, is generally estimated. It is calculated from the air kerma at the same focus skin distance on the beam central axis measured with a dosimeter. In fluoroscopy, the indirect monitoring using dose-area product meter is generally performed for estimating the entrance skin dose in real-time to avoid skin injuries. In mammography, the average glandular dose is estimated because mammary glands have more sensitive to radiation than skin. The European Organization for Quality-Assured Breast Screening and Diagnostic Services protocol has been used to estimate average glandular dose from full-field digital mammography in Japan. Although volume CT dose index or dose-length product, as seen on CT consoles, do not represent the actual dose for the patient, they are measured to assist in quality control and optimization as well as the air kerma rate at the patient entrance reference point in fluoroscopy and the average glandular dose in mammography. For the purpose of patient dose evaluation, physical dose measurements using an anthropomorphic phantom and Monte Carlo simulations can estimate patient organ doses from medical exposure.

著者

山口 恭弘

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.33, no.1, pp.12-15, 1998 (Released:2010-02-25)

参考文献数

10

著者

Haruyuki OGINO Takatoshi HATTORI

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.4, pp.194-198, 2014 (Released:2015-12-18)

参考文献数

18

被引用文献数

4 7

---

This study was designed to calculate the background lifetime risk of cancer mortality in Japan. The mortality and population data obtained from national surveys for the vital statistics and population census in 2010 are stratified at 5-year age intervals of 0-4, 5-9, ..., 80-84 with a final open interval of 85+ for use in a life table. It was found that the gender-averaged background lifetime risk of cancer mortality ranges from 23.7% to 28.3% among 47 prefectures, and the arithmetic mean was calculated to be 25.4%. It is important to consider the incremental risk of cancer mortality posed by exposure to ionizing radiation (e.g., an additive lifetime risk of 0.5% at the effective dose of 100 mSv) in the context of the level of the background lifetime risk of cancer mortality of the exposed population.

著者

鈴木 将文 佐々木 守 菊池 浩司

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.4, pp.207-218, 2018 (Released:2019-03-03)

参考文献数

17

---

We converted the measured values to the measurement value of 1 m height obtained by the calibrated survey meter by using the regression of the car-borne survey measurements on existing survey meter measurements of the absorbed dose rate in air. Detailed investigation was conducted for all factors considered to potentially influence the measured value. The equation made by these factors was nearly accordance with this regression. The result of converting the measurement results into the survey meter measurement value was 22-111 nGy h-1. Comparing the distribution map of environmental gamma-ray dose rate by car-borne survey with a geological map shows that the area with high gamma-ray dose rate coincides well with areas of Granitoid, Paleogene system and Tertiary Volcanic Rocks. The area with low gamma-ray dose rate coincides with areas of Quaternary Volcanic Rocks and their surroundings. The source of these rocks is considered to be volcanic ejecta. The annual effective dose from the geometric mean value in Aomori prefecture was estimated to be about 0.21 mSv y-1. This value is lower than the annual external dose that would be obtained by exposure to the average terrestrial gamma-ray dose rate in Japan.

著者

Shin'ichi KUDO Keiko YOSHIMOTO Hiroshige FURUTA Kazumasa INOUE Masahiro FUKUSHI Fumiyoshi KASAGI

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.146-153, 2018 (Released:2018-11-27)

参考文献数

41

被引用文献数

7

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Whether exposure to radiation at low dose and at low dose rate is related to leukemia mortality and morbidity remains controversial. Cohort studies of nuclear workers chronically exposed to radiation at low dose and at low dose rate in their workplaces provide an opportunity to directly evaluate the risks of leukemia in the lower dose ranges. Previous findings have come mostly from Western countries, with few from Asian countries. The present study aimed to examine radiation’s effects on mortality from leukemia, in a cohort of Japanese nuclear workers. The cohort consisted of 204,103 workers, who were followed from 1991 to 2010, with a total of 2.89 million person-years. The mean age and mean cumulative dose at the age at the end of follow-up were 55.6 years and 13.8 mSv. During the study, 209 leukemia deaths were observed. The linear excess relative risk (ERR) for all types of leukemia was negative, but not significant (ERR/Sv = -0.54; 90% confidence interval; -4.04, 2.96). Specific types of leukemia also showed no significant risks. A significant radiation-leukemia association for mortality was not observed in this study of Japanese nuclear workers. The cohort, however, is still young. Further follow-up is needed to obtain more reliable estimates of leukemia risks for Japanese workers exposed to low dose and low-dose rate radiation.

著者

馬淵 清彦

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.32, no.1, pp.5-8, 1997 (Released:2010-02-25)

参考文献数

4

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.53, no.2, pp.123-127, 2018 (Released:2018-09-13)

参考文献数

21

被引用文献数

1

著者

穴沢 豊 国分 守信 藤田 久美雄

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.7, no.1, pp.27-35, 1972 (Released:2010-02-25)

参考文献数

29

被引用文献数

1 2

著者

工藤 伸一 石田 淳一 吉本 恵子 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.52, no.4, pp.265-274, 2017 (Released:2018-02-24)

参考文献数

33

被引用文献数

1

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Although many radiation epidemiological studies have been carried out, there is still uncertainty about the health effects of low dose and low dose-rate radiation in humans. One reason for this uncertainty is that the risk of radiation itself may be too small to detect. Another possible reason is that the main components of cohorts or statistical method vary in each study. Comparing the Excess Relative Risks (ERRs) with other studies is often one approach; however, few studies have denoted the validity of comparing ERRs. To verify the differences in study methods, we summarized them and the results of radiation epidemiological studies to date. Some of these studies targeted high background residents or patients who received CT scans. In the present work, we focused on cohort studies among nuclear industry workers because they assured more accurate dose measurements and had no possibility of reverse causation (i.e., patients who received CT scans had worse health conditions, which prompted the need for the scans). In addition, we limited the studies to those that summarize derived excess relative risks of mortality based on a linear model.

著者

石原 隆昭

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.13, no.3, pp.171-182, 1978 (Released:2010-02-25)

参考文献数

37

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Chromosome abnormalities induced in peripheral lymphocytes are excellent biological indicators of radiation exposure. The estimate of the absorbed dose of radiation based on the chromosome aberration yield is considered the most dependable means of the biological dosimetry. In this brief review, several aspects of the use of radiation-induced chromosome abnormalities for the assessment of the biological effects of radiation are discussed; chromosome abnormalities induced by radiation, the yields of chromosome abnormalities in relation to dose, quality and dose rate of radiation, dosimetry shortly after exposure and after many years, and the capacity of chromosome abnormalities as indicators of radiation effects in the low dose level.Chromosome abnormalities to be used for the estimate are chromosome type abnormalities such as dicentrics, rings and others, among which dicentrics and rings are regarded as the most adequate since they can be easily detected, and are highly dose-dependent. On the basis of the yield of dicentrics and rings, an absorbed dose equivalent to as low as about 10rad of 60CO gamma rays may be estimated. Even many years after exposure when there are no other indicators remaining, chromosome abnormalities can still serve as fairly reliable indicators.

著者

藤波 直人 渡辺 哲也 荒木 智徳 水本 美佳 筒井 剛毅

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.39, no.3, pp.215-219, 2004 (Released:2010-08-10)

参考文献数

17