著者
赤羽 恵一 飯本 武志 伊知地 猛 岩井 敏 大口 裕之 大野 和子 川浦 稚代 立崎 英夫 辻村 憲雄 浜田 信行 藤通 有希 堀田 豊 山崎 直 横山 須美
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.3, pp.153-156, 2014 (Released:2015-07-18)
参考文献数
14
被引用文献数
3

A brief review is given of the history and methodology of external dosimetry for the lens of the eye. Under the 1989 revision to domestic radiological protection regulations, the concept on the effective dose equivalent and the dose limit to the lens of the eye (150 mSv/y) both introduced in the ICRP 1977 recommendations has changed nationwide the external monitoring methodology in non-uniform exposure situations to the trunk of a radiological worker. In such situations, which are often created by the presence of a protective apron, the worker is required to use at least two personal dosemeters, one worn on the trunk under the apron and the other, typically, at the collar over the apron. The latter dosemeter serves the dual purpose of providing the dose profile across the trunk for improved effective dose equivalent assessment and of estimating the dose to lens of the eye. The greater or appropriate value between Hp(10) and Hp(0.07), given by the dosemeter, is generally used as a surrogate of Hp(3) for recording the dose to the lens of the eye. The above-mentioned methodology was continued in the latest 2001 revision to the relevant regulations.
著者
赤羽 恵一 飯本 武志 伊知地 猛 岩井 敏 大口 裕之 大野 和子 川浦 稚代 立崎 英夫 辻村 憲雄 浜田 信行 藤通 有希 堀田 豊 山崎 直 横山 須美
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.50, no.2, pp.128-137, 2015 (Released:2016-01-09)
参考文献数
8
被引用文献数
2

While the revised dose limit for the lens of the eye was presented by the International Commission on Radiological Protection (ICRP), the dose measurement standards for the lens of the eye have been discussed in the International Organization for Standardization (ISO). In the International Basic Safety Standards of International Atomic Energy Agency (IAEA), a new ICRP dose limit of the lens of the eye was included, and a technical document was published as a guidance on the implications of the new dose limit for the lens of the eye for occupational radiation protection. By the International Radiation Protection Association (IRPA) Task Group on Implementation of Revised Dose Limits to the Lens of the Eye, the opinions for the new ICRP dose limit for the lens of the eye are investigated for the member states. In this paper, the progress of discussion in these organizations is reported.
著者
赤羽 恵一 飯本 武志 伊知地 猛 岩井 敏 大口 裕之 大野 和子 川浦 稚代 立崎 英夫 辻村 憲雄 浜田 信行 藤通 有希 堀田 豊 山崎 直 横山 須美
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.50, no.1, pp.76-89, 2015 (Released:2015-12-18)
参考文献数
52
被引用文献数
2 2

For many Japanese radiation workers in the medical, nuclear and other industrial fields, the equivalent dose of the lens of the eye will be sufficiently lower than the new ICRP dose limit. However, the dose of the lens of the eye for medical staff members who are engaged in interventional radiology and cardiology may exceed the new ICRP dose limit, especially when they are exposed closely to higher scatter radiation for a long time. In addition, the radiation dosimetry and radiation protection for emergency and recovery workers in the Fukushima Daiichi Nuclear Power Plant (FNPP1) are important issues. Thus gathering information related to the radiation dose and protection for Japanese radiation workers is important to a discussion regarding implementation of the new ICRP dose limit for the lens of the eye for Japanese regulations and planning radiation dose reduction measures. In this paper, recent studies and issues regarding radiation exposure and protection in the medical, nuclear and other industrial fields, as well as for emergency and recovery workers in the FNPP1 were summarized.
著者
赤羽 恵一 飯本 武志 伊知地 猛 岩井 敏 大口 裕之 大野 和子 川浦 稚代 立崎 英夫 辻村 憲雄 浜田 信行 藤通 有希 堀田 豊 山崎 直 横山 須美
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.50, no.1, pp.67-75, 2015 (Released:2015-12-18)
参考文献数
40
被引用文献数
3

The International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU) have been defined operational quantities and protection quantities. Dose limits have been also recommended by the ICRP using protection quantities. These quantities and some related values for main radiation such as photons, electrons, and neutrons, are summarized in this article with some historical considerations. The ICRP indicated conversion coefficients for the lens of the eye as absorbed dose per fluence as protection quantities. Equivalent dose is not used because a protection quantity that uses radiation weighting factors is not intended to be calculated for tissue reactions. So far, the ICRP has not indicated a specific RBE value for cataract formation. Operational quantities are used for measurements. There have been three types of phantoms, namely a slab phantom, a reduced phantom, and a cylindrical phantom, but none of them has been definitely recommended for the lens of the eye by the ICRP or the ICRU. Although conversion coefficients to personal dose equivalent, Hp(3), for electrons have been recommended, no other conversion coefficients to personal dose equivalent for the lens of the eye has been indicated by the ICRP or the ICRU. However, there have been several studies described personal dose equivalent. Ambient dose equivalent, H*(3), and directional dose equivalent, H'(3,a), have been indicated in several limited conditions by the ICRP and the ICRU. These status are overviewed in this article.
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.1, pp.40-44, 2019-04-18 (Released:2019-09-03)
参考文献数
21

Rainwater containing radioactive materials originating from the USA’s nuclear weapon test conducted at Bikini Atoll was observed throughout Japan in 1954. It has been reported that the maximum gross beta activity observed at that time in Kyoto was 523 pCi/mL (19,000 Bq/L). This measurement, however, focused on the gross beta activity contained in a small amount of rain sampled at the beginning of rainfall, which is different from present observations that are based on the average gross beta activity contained in rain collected during a 24-h period. As a result of reviewing and converting the 1954 data to be equivalent to current measurement, the maximum value was reduced to 50 pCi/mL (1,800 Bq/L), with a resultant surface deposition density of 310 mCi/km2 (11,000 MBq/km2). These values are well below 1/10 of the past maximum observed a few days after China’s fifth nuclear weapon test in 1966.
著者
辻村 憲雄 吉田 忠義
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.56, no.9, pp.497-508, 2007-09-15 (Released:2011-03-01)
参考文献数
24
被引用文献数
1 1

中性子線量当量 (率) 測定器の校正に使用する241Am-Be中性子線源について, 中性子放出角度分布の非等方性を計算によって評価した。ここでは, 球形の241AmO2が厚いBeに囲まれる線源モデルを仮定し, (1) AmO2表面でのα粒子のスペクトル, (2) 9Be (α, n) 反応によって発生する中性子のスペクトル, (3) 線源カプセルから漏洩する中性子のスペクトルと放出角度分布を, それぞれ順番に計算した。 (1) と (2) の計算ではα粒子の阻止能と9Be (α, n) 反応微分断面積 (JENDL/AN-2005) , (3) の計算ではモンテカルロ輸送計算コードMCNPを利用した。計算の結果, AmO2の粒径を3μmとした場合, 中性子の収率及びスペクトルがともに標準的な241Am-Be線源のものに良く一致することがわかった。また, 同じ粒径条件で算出した241Am-Be中性子線源の非等方性補正係数は, X3型線源で1.030, X4型線源で1.039となり, 文献から得られた実測値にともに良く一致した。更に, 線源カプセルの周囲に支持構造物がある場合の影響についても検討し, 中性子線量当量 (率) 測定器の校正業務において使用する非等方性補正係数を決定した。
著者
辻村 憲雄 三上 智 吉田 忠義 高田 千恵
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.40, no.3, pp.267-276, 2005 (Released:2010-08-05)
参考文献数
15

The authors studied the feasibility of utilizing ebonite as a personal neutron dosemeter in criticality accidents. A disc-shaped ebonite, a hard rubber containing 30wt% sulfur, can be used as a highly effective criticality neutron dosemeter because of a simplicity of measurements of beta activity arising from 32S(n, p)32P reactions. The counting efficiency of beta particles with an end-window GM counter for an ebonite disc in 50mm diameter and 3mm thick was determined by 252Cf neutron irradiation. The neutron spectrum dependency of 32P activity per neutron dose was computed using Monte-Carlo calculations of various neutron spectra that could be encountered in criticality accidents, and the results were tabulated as a set of spectrum correction factors. Performance tests using the SILENE reactor indicated that neutron doses could be evaluated within ±15% with the application of suitable correction factors.
著者
赤羽 恵一 飯本 武志 伊知地 猛 岩井 敏 大口 裕之 大野 和子 川浦 稚代 立崎 英夫 辻村 憲雄 浜田 信行 藤通 有希 堀田 豊 山崎 直 横山 須美
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.3, pp.145-152, 2014 (Released:2015-07-18)
参考文献数
52
被引用文献数
4

In April 2011, the International Commission on Radiological Protection (ICRP) issued the statement on tissue reactions. This stimulated interest in many countries. The Expert Committee on Radiation Protection of the Lens of the Eye was established in the Japanese Health Physics Society, and in April 2013, started discussion about the international developments and recent studies related to the dosimetry of the lens of the eye. This committee now publishes the interim report consisting of parts I-VI. Of these, this Part I overviews the structure of the eye and lens, cataract types and the scientific evidence of its new dose threshold and equivalent dose limit newly recommended by the ICRP.
著者
赤羽 恵一 飯本 武志 伊知地 猛 岩井 敏 大口 裕之 大野 和子 川浦 稚代 立崎 英夫 辻村 憲雄 浜田 信行 藤通 有希 堀田 豊 山崎 直 横山 須美
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.171-179, 2014 (Released:2015-12-18)
参考文献数
21
被引用文献数
3

Many studies have been internationally reported as part of projects regarding the radiation exposure for the lens of the eye of medical staff members under various conditions, methods of dosimetry and development of dosimeters for the lens of the eye. Recently conducted studies include the Retrospective Evaluation of Lens Injuries and Dose (RELID) of the International Atomic Energy Agency, Occupational Cataracts and Lens Opacities in interventional Cardiology (O’CLOC) study in France, Optimization of Radiation Protection of Medical Staff (ORAMED) project in European countries, and a 20-year prospective cohort study among US radiologic technologists. Given the newly implemented dose limit for the lens of the eye by the International Commission on Radiological Protection (ICRP), we summarized these studies as the necessary information for reconsideration of the Japanese dose limit for the lens of the eye. In addition, this article also covers the exposures for the lens of the eye of clean-up workers in the Chernobyl accident as shown in ICRP Publication 118 and the results of a hearing survey with specialists of the Academy of Medical Science of Ukraine.