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Fingernail electron paramagnetic resonance dosimetry protocol for localized hand exposure accident. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2022.08.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Sholom S, McKeever SWS, Escalona MB, Ryan TL, Balajee AS. A comparative validation of biodosimetry and physical dosimetry techniques for possible triage applications in emergency dosimetry. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:021515. [PMID: 35196651 DOI: 10.1088/1361-6498/ac5815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Large-scale radiological accidents or nuclear terrorist incidents involving radiological or nuclear materials can potentially expose thousands, or hundreds of thousands, of people to unknown radiation doses, requiring prompt dose reconstruction for appropriate triage. Two types of dosimetry methods namely, biodosimetry and physical dosimetry are currently utilized for estimating absorbed radiation dose in humans. Both methods have been tested separately in several inter-laboratory comparison exercises, but a direct comparison of physical dosimetry with biological dosimetry has not been performed to evaluate their dose prediction accuracies. The current work describes the results of the direct comparison of absorbed doses estimated by physical (smartphone components) and biodosimetry (dicentric chromosome assay (DCA) performed in human peripheral blood lymphocytes) methods. For comparison, human peripheral blood samples (biodosimetry) and different components of smartphones, namely surface mount resistors (SMRs), inductors and protective glasses (physical dosimetry) were exposed to different doses of photons (0-4.4 Gy; values refer to dose to blood after correction) and the absorbed radiation doses were reconstructed by biodosimetry (DCA) and physical dosimetry (optically stimulated luminescence (OSL)) methods. Additionally, LiF:Mg,Ti (TLD-100) chips and Al2O3:C (Luxel) films were used as reference TL and OSL dosimeters, respectively. The best coincidence between biodosimetry and physical dosimetry was observed for samples of blood and SMRs exposed toγ-rays. Significant differences were observed in the reconstructed doses by the two dosimetry methods for samples exposed to x-ray photons with energy below 100 keV. The discrepancy is probably due to the energy dependence of mass energy-absorption coefficients of the samples extracted from the phones. Our results of comparative validation of the radiation doses reconstructed by luminescence dosimetry from smartphone components with biodosimetry using DCA from human blood suggest the potential use of smartphone components as an effective emergency triage tool for high photon energies.
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Affiliation(s)
- Sergey Sholom
- Radiation Dosimetry Laboratory, Department of Physics, Oklahoma State University, Stillwater, OK, United States of America
| | - Stephen W S McKeever
- Radiation Dosimetry Laboratory, Department of Physics, Oklahoma State University, Stillwater, OK, United States of America
| | - Maria B Escalona
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, TN, United States of America
| | - Terri L Ryan
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, TN, United States of America
| | - Adayabalam S Balajee
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, TN, United States of America
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Lamkowski A, Combs SE, Abend M, Port M. Training of clinical triage of acute radiation casualties: a performance comparison of on-siteversus onlinetraining due to the covid-19 pandemic. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:S540-S560. [PMID: 34256358 DOI: 10.1088/1361-6498/ac13c2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
A collection of powerful diagnostic tools have been developed under the umbrellas of NATO for ionising radiation dose assessment (BAT, WinFRAT) and estimate of acute health effects in humans (WinFRAT, H-Module). We assembled a database of 191 ARS cases using the medical treatment protocols for radiation accident victims (n= 167) and the system for evaluation and archiving of radiation accidents based on case histories (n= 24) for training purposes of medical personnel. From 2016 to 2019, we trained 39 participants comprising MSc level radiobiology students in an on-site teaching class. Enforced by the covid-19 pandemic in 2020 for the first time, an online teaching of nine MSc radiobiology students replaced the on-site teaching. We found that: (a) limitations of correct diagnostic decision-making based on clinical signs and symptoms were experienced unrelated to the teaching format. (b) A significant performance decrease concerning online (first number in parenthesis) versus on-site teaching (reference and second number in parenthesis) was seen regarding the estimate time (31 vs 61 cases per hour, two-fold decrease,p= 0.005). Also, the accurate assessment of response categories (89.9% vs 96.9%,p= 0.001), ARS (92.4% vs 96.7%,p= 0.002) and hospitalisation (93.5% vs 97.0%,p= 0.002) decreased by around 3%-7%. The performances of the online attendees were mainly distributed within the lower quartile performance of on-site participants and the 25%-75% interquartile range increased 3-7-fold. (c) Comparison of dose estimates performed by training participants with hematologic acute radiation syndrome (HARS) severity mirrored the known limitations of dose alone as a surrogate parameter for HARS severity at doses less than 1.5 Gy, but demonstrated correct determination of HARS 2-4 and support for clinical decision making at dose estimates >1.5 Gy, regardless of teaching format. (d) Overall, one-third of the online participants showed substantial misapprehension and insecurities of elementary course content that did not occur after the on-site teaching.
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Affiliation(s)
- Andreas Lamkowski
- Bundeswehr Institute of Radiobiology affiliated to the University Ulm, Neuherbergstrasse 11, Munich 80937, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, Technical University of Munich (TUM), Ismaninger Straße 22, 81675 Munich, Germany
- Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München (HMGU), Ingolstaedter Landstr. 1 85764 Neuherberg, Germany
- Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site, Munich, Germany
| | - Michael Abend
- Bundeswehr Institute of Radiobiology affiliated to the University Ulm, Neuherbergstrasse 11, Munich 80937, Germany
| | - Matthias Port
- Bundeswehr Institute of Radiobiology affiliated to the University Ulm, Neuherbergstrasse 11, Munich 80937, Germany
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Hirota S, Gonzales CAB, Yasuda H, Yamaguchi I, Toyoda S. Electron spin resonance signal of human nails: increase after irradiation. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-020-07540-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractWe report the phenomenon whereby the electron spin resonance signal of human nails intensify after irradiation. Forty nail samples from three donors were divided into three groups (X-ray irradiated, γ-ray irradiated, and control). The extent of signal intensified after irradiation was proportional to the given dose under 11% humidity at 20 °C. This result seemed to contradict previous studies, reporting signal fading. Based on literature and our experimental results, we constructed a model taking both the decay and increase into consideration. Our investigation revealed that rapid deterioration in the signal intensity obscured the increase at humidity levels exceeding 40%.
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The design of X-band EPR cavity with narrow detection aperture for in vivo fingernail dosimetry after accidental exposure to ionizing radiation. Sci Rep 2021; 11:2883. [PMID: 33558592 PMCID: PMC7870891 DOI: 10.1038/s41598-021-82462-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 01/20/2021] [Indexed: 11/13/2022] Open
Abstract
For the purpose of assessing the radiation dose of the victims involved in the nuclear emergency or radiation accident, a new type of X-band EPR resonant cavity for in vivo fingernail EPR dosimetry was designed and a homemade EPR spectrometer for in vivo fingernail detection was constructed. The microwave resonant mode of the cavity was rectangular TE101, and there was a narrow aperture for fingernail detection opened on the cavity’s wall at the position of high detection sensitivity. The DPPH dot sample and the fingernail samples were measured based on the in vivo fingernail EPR spectrometer. The measurements of the DPPH dot sample verified the preliminary functional applicable of the EPR spectrometer and illustrated the microwave power and modulation response features. The fingernails after irradiation by gamma-ray were measured and the radiation-induced signal was acquired. The results indicated that the cavity and the in vivo EPR dosimeter instrument was able to detect the radiation-induced signal in irradiated fingernail, and preliminarily verified the basic function of the instrument and its potential for emergency dose estimate after a radiation accident.
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Gonzales C, Hirota S, Taño J, Yasuda H. Investigation of the dose-response in multiple irradiated fingernails and the combined effect of drying time-temperature to the ESR signal. RADIAT MEAS 2020. [DOI: 10.1016/j.radmeas.2020.106337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Sholom S, McKeever SWS. AN ADVANCE IN EPR DOSIMETRY WITH NAILS. RADIATION PROTECTION DOSIMETRY 2019; 186:60-64. [PMID: 30806471 DOI: 10.1093/rpd/ncz019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 01/15/2019] [Accepted: 01/31/2019] [Indexed: 06/09/2023]
Abstract
Olive oil is proposed as a medium for storage of nails in the time between nail harvesting and electron paramagnetic resonance (EPR) measurements to minimise the decay of the radiation-induced EPR signals (RIS). The behaviours of three main EPR signals, namely, RIS, mechanically induced and the background signals (MIS and BG, respectively), were studied for storage in olive oil. The properties of the MIS and BG signals were very similar to those previously observed for the storage in a vacuum. The RIS singlet slightly increased during the first day of storage and then remained practically unchanged at least for 6 days. Dose recovery test revealed that doses at the level 2 Gy may be reconstructed with an accuracy of about ±20%.
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Affiliation(s)
- S Sholom
- Radiation Dosimetry Laboratory, Department of Physics, Oklahoma State University, Stillwater, OK, USA
| | - S W S McKeever
- Radiation Dosimetry Laboratory, Department of Physics, Oklahoma State University, Stillwater, OK, USA
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Jo Y, Ameer K, Chung N, Kang YH, Ahn DU, Kwon JH. E-sensing, calibrated PSL, and improved ESR techniques discriminate irradiated fresh grapefruits and lemons. Journal of Food Science and Technology 2019; 57:364-374. [PMID: 31975739 DOI: 10.1007/s13197-019-04068-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/24/2019] [Accepted: 08/29/2019] [Indexed: 11/29/2022]
Abstract
Grapefruit and lemon were exposed to phytosanitary irradiation doses of 0, 0.4, and 1 kGy, and then electronic-sensing screening of irradiation status and identification of radiation-induced ESR markers were conducted during 20 days storage. Codex standard photostimulated luminescence measurement (PSL1) was not a reliable indicator of irradiation status. Electronic tongue and electronic nose, however, showed potential as screening tools for discriminating irradiated fruits from non-irradiated counterparts based on principal component analysis of taste attributes and flavor patterns. Calibrated PSL approach clearly distinguished irradiated from non-irradiated samples based on the PSL ratio (PSL2/PSL1). Verification of irradiation status by electron spin resonance spectroscopy revealed clear paramagnetic centers from both irradiated fruits samples and ethanol-vacuum drying pretreatment improved radiation-induced ESR signal detection; not prominent enough in 0.4 kGy-irradiated commodities during 20 days of storage. Peel parts of both fruits showed high limonene which proportionally increased with irradiation doses (p < 0.05 kGy).
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Affiliation(s)
- Yunhee Jo
- 1School of Food Science and Biotechnology, Kyungpook National University, Daegu, 41566 South Korea.,Health Research Department, Health and Environment Institute of Daegu, Daegu, 42183 South Korea
| | - Kashif Ameer
- 3Institute of Food and Nutritional Sciences, PMAS-Arid Agriculture University, Rawalpindi, 46300 Pakistan
| | - Namhyeok Chung
- 1School of Food Science and Biotechnology, Kyungpook National University, Daegu, 41566 South Korea
| | - Yoon-Han Kang
- 4Department of Food Processing and Distribution, Gangneung-Wonju National University, Wonju-si, Gangwon-do 26403 South Korea
| | - Dong U Ahn
- 5Department of Animal Science, Iowa State University, Ames, IA 50011-3150 USA
| | - Joong-Ho Kwon
- 1School of Food Science and Biotechnology, Kyungpook National University, Daegu, 41566 South Korea
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10
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Investigation of the applicability of the ESR nail dosimetry for assessment of accidental exposure in medical facilities. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.03.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Marciniak A, Ciesielski B, Juniewicz M, Prawdzik-Dampc A, Sawczak M. The effect of sunlight and UV lamps on EPR signal in nails. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:287-293. [PMID: 30740616 DOI: 10.1007/s00411-019-00777-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 01/12/2019] [Indexed: 06/09/2023]
Abstract
The effects of illumination of nail clippings by direct sunlight, UV lamps and fluorescent bulbs on native and radiation-induced electron paramagnetic resonance (EPR) signals in nails are presented. It is shown that a few minutes of exposure of the nail clippings to light including a UV component (sunlight and UV lamps) generates a strong EPR signal similar to the other EPR signals observable in nails: native background (BKG), mechanically induced (MIS) or radiation-induced (RIS). This effect was observed in clippings exposed and unexposed to ionizing radiation prior to the light illuminations. An exposure of the clippings to fluorescent light without a UV component generated, within the examined range of the light fluences (up to 240 kJ/m2), an EPR signal with considerably lower yield than UV light. The light-induced signal (LIS) decayed after 10 min of water treatment of the samples. In contrast, it was still observable 3 months after illumination in samples stored in air at room temperature, and 3 weeks in frozen samples, respectively. It is concluded that the LIS can considerably affect assessment of the dosimetric RIS components in irradiated nails, and of the background signals in unirradiated nails, thus contributing to errors in EPR dosimetry in nails.
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Affiliation(s)
- Agnieszka Marciniak
- Department of Physics and Biophysics, Medical University of Gdańsk, Dębinki 1, 80-211, Gdańsk, Poland.
| | - Bartłomiej Ciesielski
- Department of Physics and Biophysics, Medical University of Gdańsk, Dębinki 1, 80-211, Gdańsk, Poland
| | - Małgorzata Juniewicz
- Department of Physics and Biophysics, Medical University of Gdańsk, Dębinki 1, 80-211, Gdańsk, Poland
| | - Anita Prawdzik-Dampc
- Department of Oncology and Radiotherapy, Medical University of Gdańsk, Dębinki 7, 80-952, Gdańsk, Poland
| | - Mirosław Sawczak
- Heat Transfer Department, The Szewalski Institute of Fluid-Flow Machinery Polish Academy of Sciences, Generała Józefa Fiszera 14, 80-231, Gdańsk, Poland
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Monzen S, Ueno T, Chiba M, Mariya Y. [15. Predictive Biomarker for the Detection of Ionizing Radiation Toxicity]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2019; 75:480-485. [PMID: 31105097 DOI: 10.6009/jjrt.2019_jsrt_75.5.480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Satoru Monzen
- Department of Radiation Science, Hirosaki University Graduate School of Health Sciences
| | - Tatsuya Ueno
- Department of Radiology, Southern TOHOKU General Hospital
| | - Mitsuru Chiba
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences
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Marciniak A, Ciesielski B, Czajkowski P, Krefft K, Boguś P, Prawdzik – Dampc A, Lipniewicz J. EPR dosimetry in nail samples irradiated in vivo during total body irradiation procedures. RADIAT MEAS 2018. [DOI: 10.1016/j.radmeas.2018.06.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Ainsbury EA, Samaga D, Della Monaca S, Marrale M, Bassinet C, Burbidge CI, Correcher V, Discher M, Eakins J, Fattibene P, Güçlü I, Higueras M, Lund E, Maltar-Strmecki N, McKeever S, Rääf CL, Sholom S, Veronese I, Wieser A, Woda C, Trompier F. UNCERTAINTY ON RADIATION DOSES ESTIMATED BY BIOLOGICAL AND RETROSPECTIVE PHYSICAL METHODS. RADIATION PROTECTION DOSIMETRY 2018; 178:382-404. [PMID: 28981844 DOI: 10.1093/rpd/ncx125] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/09/2017] [Indexed: 05/16/2023]
Abstract
Biological and physical retrospective dosimetry are recognised as key techniques to provide individual estimates of dose following unplanned exposures to ionising radiation. Whilst there has been a relatively large amount of recent development in the biological and physical procedures, development of statistical analysis techniques has failed to keep pace. The aim of this paper is to review the current state of the art in uncertainty analysis techniques across the 'EURADOS Working Group 10-Retrospective dosimetry' members, to give concrete examples of implementation of the techniques recommended in the international standards, and to further promote the use of Monte Carlo techniques to support characterisation of uncertainties. It is concluded that sufficient techniques are available and in use by most laboratories for acute, whole body exposures to highly penetrating radiation, but further work will be required to ensure that statistical analysis is always wholly sufficient for the more complex exposure scenarios.
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Affiliation(s)
- Elizabeth A Ainsbury
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxford OX11 ORQ, UK
| | - Daniel Samaga
- Bundesamt für Strahlenschutz, Ingolstaedter Landstr. 1, 85764 Oberschleissheim, Germany
| | - Sara Della Monaca
- Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Maurizio Marrale
- Department of Physics and Chemistry and Advanced Technologies Network Center, University of Palermo, Viale delle Scienze Edificio 18, 90128 Palermo, Italy
| | - Celine Bassinet
- Institut de radioprotection et de sûreté nucléaire, BP 17 - 92262 Fontenay-aux-Roses Cedex 31, Avenue de la Division Leclerc 92260 Fontenay-aux-Roses, Paris, France
| | - Christopher I Burbidge
- Environmental Protection Agency, Office of Radiological Protection, 3 Clonskeagh Square, Clonskeagh Road, Dublin 14, Ireland
| | - Virgilio Correcher
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Centro de la Moncloa, Complutense, 40, 28040 Madrid, Spain
| | - Michael Discher
- University of Salzburg, Department of Geography and Geology, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Jon Eakins
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxford OX11 ORQ, UK
| | - Paola Fattibene
- Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Inci Güçlü
- Turkish Atomic Energy Authority, Mustafa Kemal Mahallesi, Dumlupinar Bulvari, No: 192, 06510, Çankaya - Ankara, Turkey
| | - Manuel Higueras
- Basque Center for Applied Mathematics, Alameda de Mazarredo 14, E-48009 Bilbao, Basque Country, Spain
| | - Eva Lund
- Department of Medical and Health Sciences, Linköping University, SE-581 85 Linköping, Sweden
| | - Nadica Maltar-Strmecki
- Ruder Boškovic Institute, Division of Physical Chemistry, Laboratory for Magnetic Resonances, Bijenicka cesta 54,10000 Zagreb, Croatia
| | - Stephen McKeever
- Oklahoma State University, 145 Physical Sciences, Campus, Stillwater, OK 74078, USA
| | - Christopher L Rääf
- Medicinsk strålningsfysik, Institutionen för Translationell Medicin, Lunds universitet, Skånes universitetssjukhus SUS, SE-205 02 Malmö, Sweden
| | - Sergey Sholom
- Oklahoma State University, 145 Physical Sciences, Campus, Stillwater, OK 74078, USA
| | - Ivan Veronese
- Università degli Studi di Milano, Department of Physics and National Institute of Nuclear Physics, Section of Milan, Via Celoria 16, 20133 - Milano, Italy
| | - Albrecht Wieser
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Institute of Radiation Protection, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Clemens Woda
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Institute of Radiation Protection, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Francois Trompier
- Institut de radioprotection et de sûreté nucléaire, BP 17 - 92262 Fontenay-aux-Roses Cedex 31, Avenue de la Division Leclerc 92260 Fontenay-aux-Roses, Paris, France
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Sholom S, McKeever S. Stability of X-band EPR signals from fingernails under vacuum storage. Radiat Phys Chem Oxf Engl 1993 2017; 141:78-87. [PMID: 28781435 DOI: 10.1016/j.radphyschem.2017.06.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
EPR signals of different origin have been tested in human finger- and toe-nails with an X-band EPR technique for different conditions of nail storage. Three different signals were identified, namely a singlet at g=2.005, a doublet at g=2.004 with a splitting constant A=1.8 mT, and an anisotropic signal at g1=2.057, g2=2.029 and g3=2.003 (positions of local extrema). All EPR spectra from nails, whether irradiated or mechanically stressed, can be described as a superposition of these three signals. The singlet is responsible for the background signal (BG), is the main component of radiation-induced signals (RIS) for low doses (100 Gy or lower) and also contributes to mechanically-induced signals (MIS). This signal is quite stable under vacuum storage, but can be reduced almost to zero by soaking in water. The behavior of this signal under ambient conditions depends on many factors, such as absorbed dose, air humidity, and ambient illumination intensity at the place of storage. The doublet arises after exposure of nails to high (few hundreds Gy and higher) doses or after mechanical stress of samples. Depending on how this signal was obtained, it may have bulk or surface locations with quite different stability properties. The surface-located doublet (generated on the nail edges during cutting or clipping) is quite unstable and decays over about two hours for samples stored at ambient conditions and within several seconds for samples immersed in water. The volume-distributed doublet decays within a few minutes in water, several hours at ambient conditions and several days in vacuum. The anisotropic signal may also be generated by both ionizing radiation and mechanical stress; this signal is quite stable in vacuum and decays over several days at ambient conditions or a few tens of minutes in water. The reference lines for the above-described three EPR signals were obtained and a procedure of spectra deconvolution was developed and tested on samples exposed to both ionizing radiation and mechanical stress.
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Affiliation(s)
- Sergey Sholom
- Radiation Dosimetry Group, Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA
| | - Stephen McKeever
- Radiation Dosimetry Group, Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA
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16
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Hayes RB, Sholom S. Retrospective Imaging and Characterization of Nuclear Material. HEALTH PHYSICS 2017; 113:91-101. [PMID: 28658054 DOI: 10.1097/hp.0000000000000680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Modern techniques for detection of covert nuclear material requires some combination of real time measurement and/or sampling of the material. More common is real time measurement of the ionizing emission caused by radioactive decay or through the materials measured in response to external interrogation radiation. One can expose the suspect material with various radiation types, including high energy photons such as x rays or with larger particles such as neutrons and muons, to obtain images or measure nuclear reactions induced in the material. Stand-off detection using imaging modalities similar to those in the medical field can be accomplished, or simple collimated detectors can be used to localize radioactive materials. In all such cases, the common feature is that some or all of the nuclear materials have to be present for the measurement, which makes sense; as one might ask, "How you can measure something that is not there?" The current work and results show how to do exactly that: characterize nuclear materials after they have been removed from an area leaving no chemical trace. This new approach is demonstrated to be fully capable of providing both previous source spatial distribution and emission energy grouping. The technique uses magnetic resonance for organic insulators and/or luminescence techniques on ubiquitous refractory materials similar in theory to the way the nuclear industry carries out worker personnel dosimetry. Spatial information is obtained by acquiring gridded samples for dosimetric measurements, while energy information comes through dose depth profile results that are functions of the incident radiation energies.
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Affiliation(s)
- Robert B Hayes
- *North Carolina State University, Nuclear Engineering Department, 2500 Stinson Dr., Raleigh, NC 27695-7909; †Oklahoma State University, Physics Department, 1110 S. Innovation Way Dr., Stillwater, OK 74074
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17
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Sholom S, McKeever SWS. Emergency EPR and OSL dosimetry with table vitamins and minerals. RADIATION PROTECTION DOSIMETRY 2016; 172:139-144. [PMID: 27412508 DOI: 10.1093/rpd/ncw177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Several table vitamins, minerals and L-lysine amino acid have been preliminarily tested as potential emergency dosemeters using electron paramagnetic resonance (EPR) and optically stimulated luminescence (OSL) techniques. Radiation-induced EPR signals were detected in samples of vitamin B2 and L-lysine while samples of multivitamins of different brands as well as mineral Mg demonstrated prominent OSL signals after exposure to ionizing radiation doses. Basic dosimetric properties of the radiation-sensitive substances were studied, namely dose response, fading of the EPR or OSL signals and values of minimum measurable doses (MMDs). For EPR-sensitive samples, the EPR signal is converted into units of dose using a linear dose response and correcting for fading using the measured fading dependence. For OSL-sensitive materials, a multi-aliquot, enhanced-temperature protocol was developed to avoid the problem of sample sensitization and to minimize the influence of signal fading. The sample dose in this case is also evaluated using the dose response and fading curves. MMDs of the EPR-sensitive samples were below 2 Gy while those of the OSL-sensitive materials were below 500 mGy as long as the samples are analyzed within 1 week after exposure.
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Affiliation(s)
- S Sholom
- Radiation Dosimetry Group, Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA
| | - S W S McKeever
- Radiation Dosimetry Group, Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA
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Bailiff I, Sholom S, McKeever S. Retrospective and emergency dosimetry in response to radiological incidents and nuclear mass-casualty events: A review. RADIAT MEAS 2016. [DOI: 10.1016/j.radmeas.2016.09.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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