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Sato T, Funamoto S, Paulbeck C, Griffin K, Lee C, Cullings H, Egbert SD, Endo A, Hertel N, Bolch WE. Dosimetric Impact of a New Computational Voxel Phantom Series for the Japanese Atomic Bomb Survivors: Methodological Improvements and Organ Dose Response Functions. Radiat Res 2020; 194:390-402. [PMID: 33045092 DOI: 10.1667/rr15546.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 06/26/2020] [Indexed: 11/03/2022]
Abstract
Owing to recent advances in computational dosimetry tools, an update is warranted for the dosimetry system for atomic bomb survivors that was established by the Joint U.S.Japan Working Group on the Reassessment of Atomic Bomb Dosimetry in 2002 (DS02). The DS02 system, and its predecessor, DS86, at the Radiation Effects Research Foundation (RERF), are based on adjoint Monte Carlo particle transport simulations coupled with stylized computational human phantoms. In our previous studies, we developed the J45 series of computational voxel phantoms representative of 1945 Japanese adults, children and pregnant females. The dosimetric impact of replacing the DS02/DS86 stylized phantoms by the J45 phantom series was also discussed through computation of organ doses for several idealized exposure scenarios. In the current study, we investigated the possible impact of introducing not only the J45 phantom series but also various methodological upgrades to the DS02 dosimetry system. For this purpose, we calculated organ doses in adults for 12 representative exposure scenarios having realistic particle energy and angular fluence, using different combinations of phantoms and dose calculation methods. Those doses were compared with survivor organ doses given by the DS02 system. It was found that the anatomical improvement in the J45 phantom series is the most important factor leading to potential changes in survivor organ doses. However, methodological upgrades, such as replacement of the adjoint Monte Carlo simulation with kerma approximation by the forward Monte Carlo simulation with secondary electron transport, can also improve the accuracy of organ doses by up to several percent.In addition, this study established a series of response functions, which allows for the rapid conversion of the unidirectional quasi-monoenergetic photon and neutron fluences from the existing DS02 system to organ doses within the J45 adult phantoms. The overall impact of introducing the response functions in the dosimetry system is not so significant, less than 10% in most cases, except for organs in which the calculation method or definition was changed, e.g., colon and bone marrow. This system of response functions can be implemented within a revision to the DS02 dosimetry system and used for future updates to organ doses within the Life Span Study of the atomic bomb survivors.
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Affiliation(s)
- Tatsuhiko Sato
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Sachiyo Funamoto
- Department of Statistics, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Colin Paulbeck
- Medical Physics Program, College of Medicine, University of Florida, Gainesville, Florida
| | - Keith Griffin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland
| | - Harry Cullings
- Department of Statistics, Radiation Effects Research Foundation, Hiroshima, Japan
| | | | - Akira Endo
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Nolan Hertel
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Wesley E Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
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Lachner J, Christl M, Alfimov V, Hajdas I, Kubik PW, Schulze-König T, Wacker L, Synal HA. 41Ca, 14C and 10Be concentrations in coral sand from the Bikini atoll. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2014; 129:68-72. [PMID: 24378732 DOI: 10.1016/j.jenvrad.2013.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 06/03/2023]
Abstract
Activation measurements of materials exposed to nuclear bomb explosions are widely used to reconstruct the neutron flux for retrospective dosimetry. In this study the applicability of coral CaCO3 as a biogenic neutron fluence dosimeter is tested. The long-lived radioisotopes (41)Ca, (14)C and (10)Be, which had been produced in nuclear bomb explosions, are measured in several coral sand samples from the Bikini atoll at the 600 kV and 200 kV AMS facilities of ETH Zurich. Elevated concentrations of all studied isotopes are found in a sample from the crater that was initially formed by the high-yield nuclear explosion Castle Bravo in 1954 and that had been used as site for several tests afterward. The observed (14)C concentration is considered too large to originate from neutron irradiation of CaCO3 alone. The relatively low concentration of (10)Be found in the crater sample indicates that production of (10)Be during nuclear bomb testing is generally minor. A simple neutron fluence reconstruction is performed on basis of the (41)Ca/(40)Ca ratio.
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Affiliation(s)
- Johannes Lachner
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
| | - Marcus Christl
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Vasily Alfimov
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Irka Hajdas
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Peter W Kubik
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Tim Schulze-König
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Lukas Wacker
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Hans-Arno Synal
- Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
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Nakamura N, Hirai Y, Kodama Y. Gamma-ray and neutron dosimetry by EPR and AMS, using tooth enamel from atomic-bomb survivors: a mini review. RADIATION PROTECTION DOSIMETRY 2012; 149:79-83. [PMID: 22267275 DOI: 10.1093/rpd/ncr478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The electron paramagnetic resonance (EPR, or electron spin resonance) method was used to measure CO₂⁻· radicals recorded in tooth enamel by exposure to atomic-bomb gamma rays. The EPR-estimated doses (i.e. ⁶⁰Co gamma-ray equivalent dose) were generally in good correlation with cytogenetic data of the same survivors, whereas plots of EPR-estimated dose or cytogenetically estimated dose against DS02 doses turned out to scatter more widely. Because those survivors whose EPR doses were higher (or lower) than DS02 doses tended to show also higher (or lower) responses for cytogenetic responses, the apparent variation appears primarily due to problems in individual DS02 doses rather than the measurement errors associated with the EPR or cytogenetic technique. A part of the enamel samples were also used for evaluation of neutron doses by measuring ⁴¹Ca/⁴⁰Ca ratios using the accelerator mass spectrometry technique. The results for the measured ratios were on average ~85 % of the calculated ratios by DS02 (but within the 95 % confidence bounds of the simulated results), which lends support to DS02-derived neutron doses to the survivors.
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Affiliation(s)
- Nori Nakamura
- Department of Genetics, Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan.
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Cullings HM, Smith KR. Better radiation exposure estimation for the Japanese atomic-bomb survivors enables us to better protect people from radiation today. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2010; 20:575-576. [PMID: 20959832 DOI: 10.1038/jes.2010.48] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Rühm W, Wallner A, Cullings H, Egbert SD, El-Faramawy N, Faestermann T, Kaul D, Knie K, Korschinek G, Nakamura N, Roberts J, Rugel G. 41Ca in Tooth Enamel. Part II: A Means for Retrospective Biological Neutron Dosimetry in Atomic Bomb Survivors. Radiat Res 2010; 174:146-54. [DOI: 10.1667/rr2044.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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