著者

谷 修祐 小嶋 光明 小野 孝二 伴 信彦 甲斐 倫明

出版者

一般社団法人 日本放射線影響学会

雑誌

日本放射線影響学会大会講演要旨集 日本放射線影響学会第54回大会

巻号頁・発行日

pp.249, 2011 (Released:2011-12-20)

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放射線によって引き起こされるC3H/HeNマウスの急性骨髄性白血病(Acute Myeloid Leukemia: AML)は、低線量でのヒトの白血病リスクを考える上で重要な実験モデルである。AMLを起こしたマウスの造血幹細胞では2番染色体の欠損およびその染色体に存在するSfpi1遺伝子の突然変異が確認されており、これらは骨髄の分化に重要な役割を持つPU.1の転写を抑制してAMLの発症に至ることが考えられている。しかし、AMLにおけるSfpi1遺伝子の突然変異について、ほとんどは点突然変異に起因し、その主な変異であるC:GからT:Aへのトランジションは自然突然変異によって生じるため、放射線によって発症する白血病のリスクを考えるためには2番染色体の欠損以外に放射線が自然突然変異率への影響を考慮する必要がある。自然突然変異は細胞が分裂する際に低確率で生じるものであるため、造血幹細胞を頂点とした各造血細胞の動態、および放射線の影響によってその動態がどのように変化するかを考慮することが重要である。本研究ではC3H/HeNマウスを用いた放射線照射実験より得られた造血幹細胞そして前駆細胞の分化、分裂のパラメータを元に、造血組織の各種動態を数理モデルで表し、各細胞数の時間的変化、およびその分裂回数をシミュレーションによる計算で求めた。また、Sfpi1遺伝子の自然突然変異確率に着目し、シミュレーションで得られた結果をもとに放射線によるマウスAML発症リスクを計算し、実験データと比較したので報告する。

著者

三浦 美和 林田 りか 高尾 秀明 小野 孝二 松田 尚樹

出版者

Japanese Society of Radiation Safety Management

雑誌

日本放射線安全管理学会誌 (ISSN:13471503)

巻号頁・発行日

vol.12, no.1, pp.46-53, 2013

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From October to December 2010, just before the radiological accident at the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant, 71 radiation professionals belonging to the radiation facilities in Japan were asked what they consider as a "safe" dose of radiation for themselves, their spouse, parents, children, brothers and friends. Although the "safe" dose varied widely from less than 1 mSv/y to higher than 100 mSv/y, the average dose was 35.6 mSv/y that was around the middle point between the exposure dose limits for annual average (20 mSv/y) and for any single year (50 mSv/y). Similar results were obtained from another surveys for the members of Japan Radioisotope Association (36.9 mSv/y) and for the Oita Prefectural Hospital (36.8 mSv/y). Among the family members and friends, the minimum average "safe" dose was 8.5 mSv/y for children, to whom 50% of responders claimed the "safe" dose less than 1 mSv. Gender, age and specialty of the responder also affected the "safe" dose. These findings suggest that the perception of radiation risk varies widely and that the legal exposure dose limit derived from the regulatory science may act as an anchor of safety even in radiation professionals. The different level of risk perception for different target groups in radiation professionals appears similar to those in non-professional whole population. The gap between these characteristics of real radiation professionals and the generally accepted picture of radiation professionals might take a part in a state of confusion after the radiological accident.

著者

三浦 美和 林田 りか 高尾 秀明 小野 孝二 松田 尚樹

出版者

日本放射線安全管理学会

雑誌

日本放射線安全管理学会誌 (ISSN:13471503)

巻号頁・発行日

vol.12, no.1, pp.46-53, 2013 (Released:2013-07-26)

参考文献数

21

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From October to December 2010, just before the radiological accident at the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant, 71 radiation professionals belonging to the radiation facilities in Japan were asked what they consider as a “safe” dose of radiation for themselves, their spouse, parents, children, brothers and friends. Although the “safe” dose varied widely from less than 1 mSv/y to higher than 100 mSv/y, the average dose was 35.6 mSv/y that was around the middle point between the exposure dose limits for annual average (20 mSv/y) and for any single year (50 mSv/y). Similar results were obtained from another surveys for the members of Japan Radioisotope Association (36.9 mSv/y) and for the Oita Prefectural Hospital (36.8 mSv/y). Among the family members and friends, the minimum average “safe” dose was 8.5 mSv/y for children, to whom 50% of responders claimed the “safe” dose less than 1 mSv. Gender, age and specialty of the responder also affected the “safe” dose. These findings suggest that the perception of radiation risk varies widely and that the legal exposure dose limit derived from the regulatory science may act as an anchor of safety even in radiation professionals. The different level of risk perception for different target groups in radiation professionals appears similar to those in non-professional whole population. The gap between these characteristics of real radiation professionals and the generally accepted picture of radiation professionals might take a part in a state of confusion after the radiological accident.

著者

藤淵 俊王 藤田 克也 五十嵐 隆元 西丸 英治 堀田 昇吾 桜井 礼子 小野 孝二

出版者

公益社団法人 日本放射線技術学会

雑誌

日本放射線技術学会雑誌 (ISSN:03694305)

巻号頁・発行日

vol.77, no.2, pp.160-171, 2021 (Released:2021-02-20)

参考文献数

21

被引用文献数

2

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Purpose: To investigate the actual condition of the crystalline lens equivalent dose and effective dose according to the type of job and the type of duties in a medical institution. We also sought to clarify effective exposure reduction strategies. Methods: Equivalent crystalline lens doses, effective doses, job type, and duties for 8656 persons · year were obtained from 17 medical facilities. We analyzed the relationship between the effective dose and the crystalline lens equivalent dose in uniform exposure control and non-uniform exposure control conditions. Exposure data were obtained for 13 unique job types and duties. Results: The ratio of the lens equivalent dose to the effective dose of non-uniform exposure managers was 2 to 6 times and varied depending on the occupation. The percentage of persons whose annual lens equivalent dose exceeded 20 mSv was 4.75% for medical doctors, 1.17% for nurses, and 0.24% for radiological technologists. Highly exposed tasks included doctors in cardiology and gastroenterology performing angiography and endoscopy, nurses in endoscopy, and radiological technologists in radiography and CT examinations. Conclusion: Thorough unequal exposure control for operations with high crystalline lens exposure, radiation protection education, and effective use of proper personal protective equipment such as the use of radiation protection glasses may reduce lens exposure levels.

著者

日本保健物理学会医療放射線リスク専門研究会 甲斐 倫明 伴 信彦 太田 勝正 小野 孝二 酒井 一夫 長谷川 隆幸 福士 政広 吉永 信治

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.46, no.1, pp.42-51, 2011-03-01

参考文献数

20

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Radiation use in medicine generally gives us the benefit that outweighs the risk. However, some patients are much concerned about the risk while some medical people are unaware of radiation risk. The aim of this report is to review the low dose risk not only in the reports of ICRP, UNSCEAR, BEIR and French academy but also in the scientific papers that have been paid attention to. On these bases, we discuss the low dose risk and how we face the risk in medicine in order to go for medical use of radiation to the right way. In particular, we hope this report will support medical people as well as radiation protection experts should understand the radiation risk in medicine on current scientific basis.