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Mitsuyasu Y, Oka T, Takahashi A, Kino Y, Okutsu K, Sekine T, Yamashita T, Shimizu Y, Chiba M, Suzuki T, Osaka K, Sasaki K, Suzuki M, Fukumoto M, Shinoda H. Estimation of external dose for wild Japanese macaques captured in Fukushima prefecture: decomposition of electron spin resonance spectrum. RADIATION PROTECTION DOSIMETRY 2023; 199:1620-1625. [PMID: 37721074 DOI: 10.1093/rpd/ncad146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 03/28/2023] [Accepted: 04/05/2023] [Indexed: 09/19/2023]
Abstract
The signal intensities of CO2- radicals in teeth can be utilised as an individual indicator of the cumulative external dose for animals. To accurately determine the external dose, it is desirable to analyse the CO2- radical intensity and improve its detection limit. We recently reported a dose-response in the range of 0-200 mGy and estimated the absorbed dose for seven wild Japanese macaques captured in/around the related areas to the Fukushima Daiichi Nuclear Power Plant accident. Herein, for further improvement of this method, we examined the electron spin resonance spectra of the teeth of these seven and an additional four macaques captured in Fukushima by applying two spectrum-decomposition algorithms.
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Affiliation(s)
- Yusuke Mitsuyasu
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Toshitaka Oka
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Atsushi Takahashi
- Tohoku University Hospital, Tohoku University, Sendai, Miyagi 980-8574, Japan
| | - Yasushi Kino
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Kenichi Okutsu
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Tsutomu Sekine
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Takuma Yamashita
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
- Institute for Excellence in Higher Education, Tohoku University, Sendai, Miyagi 980-8576, Japan
| | - Yoshinaka Shimizu
- Graduate School of Dentistry, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Mirei Chiba
- Graduate School of Dentistry, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Toshihiko Suzuki
- Graduate School of Dentistry, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Ken Osaka
- Graduate School of Dentistry, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Keiichi Sasaki
- Graduate School of Dentistry, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Masatoshi Suzuki
- International Research Institute of Disaster Science, Tohoku University, Sendai, Miyagi 980-8572, Japan
| | - Manabu Fukumoto
- International Research Institute of Disaster Science, Tohoku University, Sendai, Miyagi 980-8572, Japan
- Center for Advanced Intelligence Project, RIKEN, Nihonbashi, Tokyo 103-0027, Japan
| | - Hisashi Shinoda
- Graduate School of Dentistry, Tohoku University, Sendai, Miyagi 980-8575, Japan
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Ghimire L, Waller E. Methodology and Instrumentation for Electron Paramagnetic Resonance Dosimetry With Tooth Enamel. JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE 2023. [DOI: 10.1115/1.4055162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
When tooth enamel is exposed to ionizing radiation, it generates a dose-dependent concentration of free radical centers (i.e., unpaired electrons). The concentration of these free radical centers is identified and quantified using electron paramagnetic resonance (EPR) spectroscopy in the form of an EPR spectrum. The intensity of the spectrum is proportional to the absorbed dose. Four international intercomparisons have already demonstrated that the EPR tooth enamel dosimetric technique is reliable for retrospective dose assessment in acute and chronic exposure scenarios. Additionally, EPR dosimetry is regarded same as a gold standard for reconstructing the total lifetime dose of individuals using tooth enamel. The accuracy and reproducibility of EPR dose reconstruction depend on the sample preparation, spectrum acquisition, and EPR spectra analysis techniques. So, this paper reviews some of the widely applied and accepted laboratory protocols or methodologies for the EPR dosimetric methods. The minimum detection limit in tooth enamel using this technique was 30 mGy. So, this review aims to share these protocols so that it would be easy to reconstruct the accident doses or chronic exposures with reliable accuracy and precision. Different bands (e.g., L, X, Q, etc.) continuous wave (CW) EPR spectrometers have been used in many historical and accident dose reconstructions; however, due to the availability, moderate price, and not being much influenced by the small amount of moisture in a sample, the X-band has been widely used. A well-developed methodology, a highly sensitive EPR spectrometer, and a well-trained operator are vital for the reliable measurements of absorbed low doses in EPR dosimetry with tooth enamel.
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Affiliation(s)
- Lekhnath Ghimire
- Faculty of Energy Systems and Nuclear Science, Ontario Tech University , Oshawa, ON L1G 0C5, Canada
| | - Edward Waller
- Faculty of Energy Systems and Nuclear Science, Ontario Tech University , Oshawa, ON L1G 0C5, Canada
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Pederson SL, Li Puma MC, Hayes JM, Okuda K, Reilly CM, Beasley JC, Li Puma LC, Hinton TG, Johnson TE, Freeman KS. Effects of chronic low-dose radiation on cataract prevalence and characterization in wild boar (Sus scrofa) from Fukushima, Japan. Sci Rep 2020; 10:4055. [PMID: 32132563 PMCID: PMC7055243 DOI: 10.1038/s41598-020-59734-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/21/2020] [Indexed: 12/03/2022] Open
Abstract
This study evaluated cataracts in wild boar exposed to chronic low-dose radiation. We examined wild boar from within and outside the Fukushima Exclusion Zone for nuclear, cortical, and posterior subcapsular (PSC) cataracts in vivo and photographically. Plausible upper-bound, lifetime radiation dose for each boar was estimated from radioactivity levels in each animal's home range combined with tissue concentrations of 134+137Cesium. Fifteen exposed and twenty control boar were evaluated. There were no significant differences in overall prevalence or score for cortical or PSC cataracts between exposed and control animals. Nuclear (centrally located) cataracts were significantly more prevalent in exposed boar (p < 0.05) and had statistically higher median scores. Plausible upper-bound, lifetime radiation dose ranged from 1 to 1,600 mGy in exposed animals, with no correlation between dose and cortical or PSC score. While radiation dose and nuclear score were positively associated, the impact of age could not be completely separated from the relationship. Additionally, the clinical significance of even the highest scoring nuclear cataract was negligible. Based on the population sampled, wild boar in the Fukushima Exclusion Zone do not have a significantly higher prevalence or risk of cortical or PSC cataracts compared to control animals.
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Affiliation(s)
- Samantha L Pederson
- Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States
| | - Margaret C Li Puma
- Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States
| | - Joshua M Hayes
- Environmental Radiological and Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States
| | - Kei Okuda
- Institute of Environmental Radioactivity, Fukushima University, Fukushima, Japan
| | | | - James C Beasley
- Savannah River Ecology Laboratory and Warnell School of Forestry and Natural Resources, University of Georgia, Aiken, South Carolina, United States
| | - Lance C Li Puma
- Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States
| | - Thomas G Hinton
- Institute of Environmental Radioactivity, Fukushima University, Fukushima, Japan
| | - Thomas E Johnson
- Environmental Radiological and Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States
| | - Kate S Freeman
- Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States.
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