文献一覧: Ryuji Okazaki (著者)

37 0 0 0 OA The History of the Radiation Damage in Occupations

著者: Ryuji OKAZAKI
出版者: The University of Occupational and Environmental Health, Japan
雑誌: Journal of UOEH (ISSN:0387821X)
巻号頁・発行日: vol.36, no.1, pp.27-31, 2014-03-01 (Released:2014-03-14)
参考文献数: 6
被引用文献数: 1

1895年にレントゲンがX線を発見した翌年には,手の皮膚炎が約60件,また脱毛の報告がされている.慢性放射線皮膚炎はX線管の製作者や医師・技師などX線を職業として扱う人に現れ,これが最初の職業被曝である.その後皮膚がんを含めた晩発障害の発生は医師・技師の深刻な職業病と捉えられている.1910年代に放射線を扱っている人の血液障害,特に白血病の発生が目を引くようになった.1914年頃からダイヤルペインターが夜光時計文字盤にラジウムを混ぜて塗布したことによる骨髄炎が生じている.その他放射線による障害は,1986年チェルノブイリ原子力発電所事故における放射線死や発がん,1999年東海村JCO臨界事故における放射線死などがある.2011年東京電力福島第一原子力発電所事故における放射線障害はまだみられていないが,今後のフォローは必要である.

2022-05-28 08:01:16
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12 0 0 0 OA Ryugu particles found outside the Hayabusa2 sample container

著者: Aiko Nakato Shiori Inada Shizuho Furuya Masahiro Nishimura Toru Yada Masanao Abe Tomohiro Usui Hideto Yoshida Takashi Mikouchi Kanako Sakamoto Hajime Yano Yayoi N. Miura Yoshinori Takano Shinji Yamanouchi Ryuji Okazaki Hirotaka Sawada Shogo Tachibana
出版者: GEOCHEMICAL SOCIETY OF JAPAN
雑誌: GEOCHEMICAL JOURNAL (ISSN:00167002)
巻号頁・発行日: pp.GJ22017, (Released:2022-10-21)
被引用文献数: 13

The Hayabusa2 spacecraft explored C-type near-Earth asteroid (162173) Ryugu and returned asteroidal materials, collected during two touchdown operations, to the Earth as the first sample from carbonaceous-type asteroid. The sample container, in which ~5 g of Ryugu sample was enclosed, was safely opened in the clean chamber system with no severe exposure to the terrestrial atmosphere. In the course of preparation operation of the sample container, two dark-colored millimeter- to sub-millimeter-sized particles were found outside the sealing part of the sample container. Because they look similar to the Ryugu particles inside the sample container, the particles were named as Q particles (Q from questionable). In this study, we investigated Q particles (Q001 and Q002) mineralogically and petrographically to compare them with potential contaminants (the ablator material of the reentry capsule and fine sand particles at the capsule landing site), Ryugu sample, and CI chondrites. The Q particles show close resemblance to Ryugu sample and CI chondrites, but have no evidence of terrestrial weathering that CI chondrites experienced. We therefore conclude that the Q particles are originated from Ryugu and were expelled from the sample catcher (sample storage canister) in space prior to the enclosure operation of the sample catcher in the sample container. The most likely scenario is that the Q particles escaped from the sample catcher during the retrieval of the sample collection reflector, which was the necessary operation for the sample container closing.

2023-03-24 09:53:31
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2 0 0 0 OA How Occupational Health Can Contribute in a Disaster and What We Should Prepare for the Future–Lessons Learned through Support Activities of a Medical School at the Fukushima Daiichi Nuclear Power Plant in Summer 2011

著者: Koji Mori Seiichiro Tateishi Koh Hiraoka Toshihiko Kubo Ryuji Okazaki Katsunori Suzuki Yuichi Kobayashi Kimitoshi Kohno
出版者: (公社)日本産業衛生学会
雑誌: Journal of Occupational Health (ISSN:13419145)
巻号頁・発行日: pp.12-0134-CS, (Released:2012-11-27)
被引用文献数: 7 26 3

A nuclear accident occurred at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company (TEPCO) as a result of a mega-earthquake and tsunami in March, 2011. A large number of workers were engaged in response and recovery operations under a complex structure of involved companies. They were exposed not only to radiation but also to other health hazards. TEPCO implemented programs to prevent radiation exposure, but had no effective systems for managing the other health risks and few occupational health (OH) professionals contributed to the health risk management. The University of Occupational and Environmental Health (UOEH), Japan, dispatched physicians to a quake-proof building at the plant t provide first-aid services from mid-May, 2011, and took a strategic approach to protecting workers’ from existing health risks. UOEH presented recommendations on OH systems and preventive measures against heat stress to the Government and TEPCO. The Ministry of Health, Labour, and Welfare issued guidelines to TEPCO and contractors. TEPCO implemented a comprehensive program against heat stress according to the guidelines and in cooperation with UOEH. As a result, we successfully prevented severe heat illness during summer 2011. From our experiences, we believe that the following recommendations should be considered: 1) the role of OH and the participation of experts should be defined in emergency response plans; 2) regulations should allow the national government and main companies involved to lead safety and health initiatives for all workers at disaster sites; and 3) OH professionals, response manuals and drills should be organized at a national level.

2012-12-04 19:03:03
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1 0 0 0 OA Ryugu particles found outside the Hayabusa2 sample container

著者: Aiko Nakato Shiori Inada Shizuho Furuya Masahiro Nishimura Toru Yada Masanao Abe Tomohiro Usui Hideto Yoshida Takashi Mikouchi Kanako Sakamoto Hajime Yano Yayoi N. Miura Yoshinori Takano Shinji Yamanouchi Ryuji Okazaki Hirotaka Sawada Shogo Tachibana
出版者: GEOCHEMICAL SOCIETY OF JAPAN
雑誌: GEOCHEMICAL JOURNAL (ISSN:00167002)
巻号頁・発行日: vol.56, no.6, pp.197-222, 2022 (Released:2022-12-16)
参考文献数: 60
被引用文献数: 13

2023-01-12 21:48:56
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