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Ferreira MF, Turner A, Vernon EL, Grisolia C, Lebaron-Jacobs L, Malard V, Jha AN. Tritium: Its relevance, sources and impacts on non-human biota. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162816. [PMID: 36921857 DOI: 10.1016/j.scitotenv.2023.162816] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Tritium (3H) is a radioactive isotope of hydrogen that is abundantly released from nuclear industries. It is extremely mobile in the environment and in all biological systems, representing an increasing concern for the health of both humans and non-human biota (NHB). The present review examines the sources and characteristics of tritium in the environment, and evaluates available information pertaining to its biological effects at different levels of biological organisation in NHB. Despite an increasing number of publications in the tritium radiobiology field, there exists a significant disparity between data available for the different taxonomic groups and species, and observations are heavily biased towards marine bivalves, fish and mammals (rodents). Further limitations relate to the scarcity of information in the field relative to the laboratory, and lack of studies that employ forms of tritium other than tritiated water (HTO). Within these constraints, different responses to HTO exposure, from molecular to behavioural, have been reported during early life stages, but the potential transgenerational effects are unclear. The application of rapidly developing "omics" techniques could help to fill these knowledge gaps and further elucidate the relationships between molecular and organismal level responses through the development of radiation specific adverse outcome pathways (AOPs). The use of a greater diversity of keystone species and exposures to multiple stressors, elucidating other novel effects (e.g., by-stander, germ-line, transgenerational and epigenetic effects) offers opportunities to improve environmental risk assessments for the radionuclide. These could be combined with artificial intelligence (AI) including machine learning (ML) and ecosystem-based approaches.
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Affiliation(s)
- Maria Florencia Ferreira
- School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Andrew Turner
- School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Emily L Vernon
- School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | | | | | - Veronique Malard
- Aix Marseille Univ, CEA, CNRS, BIAM, IPM, F-13108 Saint Paul-Lez-Durance, France
| | - Awadhesh N Jha
- School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
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Transcriptome Analysis of the Immortal Human Keratinocyte HaCaT Cell Line Damaged by Tritiated Water. BIOLOGY 2023; 12:biology12030405. [PMID: 36979097 PMCID: PMC10045445 DOI: 10.3390/biology12030405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/05/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023]
Abstract
Radioactive elements, such as tritium, have been released into the ocean in large quantities as a result of the reactor leakage accident. In this study, an MTT assay demonstrated that the viability of HacaT cells decreased after tritiated water treatment. Bioinformatics analysis was used to analyze gene changes in the HacaT cells. The sequencing results showed 267 significantly differentially expressed genes (DEGs), and GO enrichment analysis showed that the DEGs were mainly divided into three parts. The KEGG pathway analysis showed that the up-regulated DEGs were involved in Wnt and other pathways, while the down-regulated DEGs were involved in Jak–STAT and others. A Western blot assay was used to verify the parts of the sequencing results. This study was the first to explore the mechanism of tritiated water on HacaT cells using Transcriptome analysis. The results will provide a theoretical basis for the study of tritiated water hazard mechanisms.
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Mothersill C, Cocchetto A, Seymour C. Low Dose and Non-Targeted Radiation Effects in Environmental Protection and Medicine-A New Model Focusing on Electromagnetic Signaling. Int J Mol Sci 2022; 23:11118. [PMID: 36232421 PMCID: PMC9570230 DOI: 10.3390/ijms231911118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/17/2022] Open
Abstract
The role of signalling in initiating and perpetuating effects triggered by deposition of ionising radiation energy in parts of a system is very clear. Less clear are the very early steps involved in converting energy to chemical and biological effects in non-targeted parts of the system. The paper aims to present a new model, which could aid our understanding of the role of low dose effects in determining ultimate disease outcomes. We propose a key role for electromagnetic signals resulting from physico-chemical processes such as excitation decay, and acoustic waves. These lead to the initiation of damage response pathways such as elevation of reactive oxygen species and membrane associated changes in key ion channels. Critically, these signalling pathways allow coordination of responses across system levels. For example, depending on how these perturbations are transduced, adverse or beneficial outcomes may predominate. We suggest that by appreciating the importance of signalling and communication between multiple levels of organisation, a unified theory could emerge. This would allow the development of models incorporating time, space and system level to position data in appropriate areas of a multidimensional domain. We propose the use of the term "infosome" to capture the nature of radiation-induced communication systems which include physical as well as chemical signals. We have named our model "the variable response model" or "VRM" which allows for multiple outcomes following exposure to low doses or to signals from low dose irradiated cells, tissues or organisms. We suggest that the use of both dose and infosome in radiation protection might open up new conceptual avenues that could allow intrinsic uncertainty to be embraced within a holistic protection framework.
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Affiliation(s)
- Carmel Mothersill
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Alan Cocchetto
- National CFIDS Foundation, 285 Beach Ave., Hull, MA 02045-1602, USA
| | - Colin Seymour
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
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Mothersill C, Seymour C. Low dose radiation mechanisms: The certainty of uncertainty. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 876-877:503451. [PMID: 35483782 DOI: 10.1016/j.mrgentox.2022.503451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 02/06/2023]
Abstract
This paper reviews the current understanding of low dose radiobiology, and how it has evolved from classical target theory. It highlights the uncertainty around low dose effects, which is due in part to the complexity of "context" surrounding the ultimate expression of biological effects following low dose exposure. The paper makes special reference to low dose non-targeted effects which, are currently ignored in radiation protection and population level risk assessment, because it is unclear what they mean for risk. The view of the authors is that this "lack of clarity" about what the effects mean is precisely the point. It indicates the uncertainty of outcomes after a given exposure. The uncertainty stems from multiple outcome options resulting from the intrinsic uncertainty of the stochastic interaction of low dose radiation with matter. This uncertainty should be embraced rather than eschewed. The impacts of the uncertainties identified in this paper is explored and an approach to quantifying mutation probability in relation to dose is presented.
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Affiliation(s)
- Carmel Mothersill
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
| | - Colin Seymour
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
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Vo NTK, Singh H, Stuart M, Seymour CB, Mothersill CE. A pilot study of radiation-induced bystander effect in radio-adapting frogs at a radiologically contaminated site located on the chalk river laboratories property. Int J Radiat Biol 2021; 98:1139-1146. [PMID: 34586949 DOI: 10.1080/09553002.2021.1987558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE To measure medium borne bystander effects, to study the influence of radioadaptive response (RAR) on bystander response, and to discover reliable radioresponsive biomarkers in radio-adapting frogs from Duke Swamp contaminated with an above-background radiation level and in naïve frogs from Twin Lake as the background control site. MATERIALS AND METHODS Frogs were captured at Duke Swamp and Twin Lake and brought to the lab at the Canadian Nuclear Laboratories facility. Half of the frogs from each site were irradiated with 4 Gy while the other half of the frogs were left with no further radiation treatment. Frog bladders were removed and placed in sterile culture media. Upon arrival at McMaster University, the bladders were processed for tissue cultures. After 48 h, the culture media conditioned by the bladder explants were harvested for clonogenic reporter survival assay and calcium flux measurements for assessing bystander effects. HPV-G cells were used as bystander reporter cells in all radiation-induced bystander effect (RIBE) assays. The frog bladder cultures were incubated for another 10-12 days followed by immunochemical staining for bcl-2 and c-myc expressions to analyze cellular anti-apoptotic (pro-survival) and pro-apoptotic (pro-death) responses, respectively. RESULTS Only culture media conditioned by bladders from 4-Gy-irradiated naïve frogs from Twin Lake induced bystander effects (reduction of HPV-G reporter cells' clonogenic survival and presence of strong calcium flux activities). The 4 Gy irradiation dose increased pro-apoptotic c-myc expression in naïve frogs' bladder explants. Culture media conditioned by bladders from radio-adapting frogs from Duke Swamp enhanced HPV-G's clonogenic survival and a 4 Gy irradiation challenge did not change the enhanced clonogenic survival nature nor induce calcium flux. In bladder explants from both control and 4-Gy-irradiated radio-adapting frogs, anti-apoptotic bcl-2 expression for pro-survival responses was ubiquitous while c-myc expression for pro-death responses was limited to a small fraction of cells. CONCLUSION The clonogenic RIBE reporter assay using HPV-G and calcium flux measurements are useful diagnostic tools for RIBE assessment of field biological samples, specifically those from frogs. RAR induced by environmentally relevant low-dose radiation induces protective bystander response. Bcl-2 and c-myc are reliable biomarkers for evaluating low dose radiation responses in wild populations of amphibians. Overall, this pilot study emphasizes the importance of looking at non-targeted effects (NTEs) in natural populations of non-human biota that could be vulnerable to chronic low-dose radiation exposures.
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Affiliation(s)
- Nguyen T K Vo
- Department of Medical Physics and Applied Radiation Sciences, Hamilton, Canada.,Department of Biology, McMaster University, Hamilton, Canada
| | - Harleen Singh
- Department of Medical Physics and Applied Radiation Sciences, Hamilton, Canada.,Buffalo General Hospital, Buffalo, NY, USA
| | | | - Colin B Seymour
- Department of Medical Physics and Applied Radiation Sciences, Hamilton, Canada.,Department of Biology, McMaster University, Hamilton, Canada
| | - Carmel E Mothersill
- Department of Medical Physics and Applied Radiation Sciences, Hamilton, Canada.,Department of Biology, McMaster University, Hamilton, Canada
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Vo NTK. Environmental radiobiology of amphibians - knowledge gaps to be filled using cell lines. Int J Radiat Biol 2021; 98:1034-1046. [PMID: 33428858 DOI: 10.1080/09553002.2021.1872815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Amphibians are facing an unprecedented level of population declines worldwide. The causes run the gamut from habitat loss and succumbing to opportunistic pathogen infections to vulnerability to toxic pollutants and ultraviolet (UV)-B radiation exposure. Anthropogenic activities including Chernobyl and Fukushima nuclear disasters and radioactive waste leakage into the environment raise the background radiation levels. Their immediate and chronic effects on amphibian populations are still being studied. However, the literature on environmental radiation effects on amphibian health still requires a lot more work. Laboratory and field works need to be conducted hand in hand in order to make informative and conclusive analyses to distinguish bad from good and harm from risk or to argue for or against the linear no-threshold model in radioprotection programs. Amphibian cell lines can help seek answers to important questions pertaining environmental radiobiology and amphibian health wherever they can suitably and effectively. The purpose of this work is to show that amphibian cell lines can 'rescue' important knowledge gaps in the literature, especially in the low-dose radiation mechanisms. Presently, there are 142 amphibian cell lines developed from six urodelans and 17 anurans. Amphibian cell lines can help expand and enrich the limited literature on environmental radiation effects on amphibians. They can be used to study mechanisms of radiation actions and discover reliable biomarkers for low-dose exposure. They can be used in environmental radiation monitoring and radioprotection programs. They can be used to determine the effects of co-exposure of IR and other stressors in the environment on amphibian health. They represent an ethical choice for amphibian conservation efforts in the current global amphibian declines. Lessons learned from cellular data can be useful guides to gain a better picture of effects occurring at the amphibian population and ecosystem levels.
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Affiliation(s)
- Nguyen T K Vo
- Department of Biology, McMaster University, Hamilton, Canada.,School of Interdisciplinary Science, McMaster University, Hamilton, Canada
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7
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Mothersill CE, Oughton DH, Schofield PN, Abend M, Adam-Guillermin C, Ariyoshi K, Beresford NA, Bonisoli-Alquati A, Cohen J, Dubrova Y, Geras’kin SA, Hevrøy TH, Higley KA, Horemans N, Jha AN, Kapustka LA, Kiang JG, Madas BG, Powathil G, Sarapultseva EI, Seymour CB, Vo NTK, Wood MD. From tangled banks to toxic bunnies; a reflection on the issues involved in developing an ecosystem approach for environmental radiation protection. Int J Radiat Biol 2020; 98:1185-1200. [DOI: 10.1080/09553002.2020.1793022] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | | | - Paul N. Schofield
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Michael Abend
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | | | - Kentaro Ariyoshi
- Integrated Center for Science and Humanities, Fukushima Medical University, Fukushima City, Japan
| | | | | | - Jason Cohen
- Department of Biology and Department of Physics and Astronomy, McMaster University, Hamilton, Canada
| | - Yuri Dubrova
- Department of Genetics, University of Leicester, Leicester, UK
| | | | | | - Kathryn A. Higley
- School of Nuclear Science and Engineering, Oregon State University, Corvallis, OR, USA
| | - Nele Horemans
- Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Awadhesh N. Jha
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, UK
| | | | - Juliann G. Kiang
- Armed Forces Radiobiology Research Institute, Uniformed services University of the Health Sciences, Bethesda, MD, USA
| | - Balázs G. Madas
- Environmental Physics Department, Centre for Energy Research, Budapest, Hungary
| | - Gibin Powathil
- Department of Mathematics, Computational Foundry, Swansea University, Swansea, UK
| | | | | | - Nguyen T. K. Vo
- Department of Biology and Department of Physics and Astronomy, McMaster University, Hamilton, Canada
| | - Michael D. Wood
- School of Science, Engineering & Environment, University of Salford, Salford, UK
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8
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Gagnaire B, Gosselin I, Festarini A, Walsh S, Cavalié I, Adam-Guillermin C, Della-Vedova C, Farrow F, Kim SB, Shkarupin A, Chen HQ, Beaton D, Stuart M. Effects of in vivo exposure to tritium: a multi-biomarker approach using the fathead minnow, Pimephales promelas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:3612-3623. [PMID: 30460657 DOI: 10.1007/s11356-018-3781-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/15/2018] [Indexed: 06/09/2023]
Abstract
Tritium (3H) is a radioactive isotope of hydrogen. In the environment, the most common form of tritium is tritiated water (HTO). However, tritium can also be incorporated into organic molecules, forming organically bound tritium (OBT). The present study characterized the effects of tritium on the health of the fathead minnow, Pimephales promelas. Fish were exposed to a gradient of HTO (activity concentrations of 12,000, 25,000, and 180,000 Bq/L) and OBT using food spiked with tritiated amino acids (OBT only, with an activity concentration of 27,000 Bq/L). A combined exposure condition where fish were placed in 25,000 Bq/L water and received OBT through feed was also studied. Fish were exposed for 60 days, followed by a 60-day depuration period. A battery of health biomarkers were measured in fish tissues at seven time points throughout the 120 days required to complete the exposure and depuration phases. HTO and OBT were also measured in fish tissues at the same time points. Results showed effects of increasing tritium activity concentrations in water after 60 days of exposure. The internal dose rates of tritium, estimated from the tissue free-water tritium (TFWT) and OBT activity concentrations, reached a maximum of 0.65 μGy/h, which is relatively low considering background levels. No effects were observed on survival, fish condition, and metabolic indices (gonado-, hepato-, and spleno-somatic indexes (GSI, HSI, SSI), RNA/DNA and proteins/DNA ratios). Multivariate analyses showed that several biomarkers (DNA damages, micronucleus frequency, brain acetylcholinesterase, lysosomal membrane integrity, phagocytosis activity, and reactive oxygen species production) were exclusively correlated with fish tritium internal dose rate, showing that tritium induced genotoxicity, as well as neural and immune responses. The results were compared with another study on the same fish species where fish were exposed to tritium and other contaminants in natural environments. Together with the field study, the present work provides useful data to identify biomarkers for tritium exposure and better understand modes of action of tritium on the fathead minnow.
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Affiliation(s)
- Béatrice Gagnaire
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada.
| | - Isabelle Gosselin
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Amy Festarini
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Stephanie Walsh
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Isabelle Cavalié
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint-Paul-lez-Durance, France
| | - Christelle Adam-Guillermin
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint-Paul-lez-Durance, France
| | - Claire Della-Vedova
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, Cadarache, 13115, Saint-Paul-lez-Durance, France
| | - Francesca Farrow
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Sang Bog Kim
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Alexi Shkarupin
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Hui Qun Chen
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Danielle Beaton
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
| | - Marilyne Stuart
- Canadian Nuclear Laboratories (formerly Atomic Energy of Canada Limited), Chalk River Laboratories, 286 Plant Road, Chalk River, ON, K0J 1J0, Canada
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Mothersill C, Seymour C. Targets, pools, shoulders, and communication – a reflection on the evolution of low-dose radiobiology. Int J Radiat Biol 2019; 95:851-860. [DOI: 10.1080/09553002.2019.1589016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Colin Seymour
- Department of Biology, McMaster University, Hamilton, ON, Canada
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10
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Rusin A, Lapied E, Le M, Seymour C, Oughton D, Haanes H, Mothersill C. Effect of gamma radiation on the production of bystander signals from three earthworm species irradiated in vivo. ENVIRONMENTAL RESEARCH 2019; 168:211-221. [PMID: 30317106 DOI: 10.1016/j.envres.2018.09.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 09/03/2018] [Accepted: 09/19/2018] [Indexed: 06/08/2023]
Abstract
The effect of gamma radiation delivered over 24 h on the induction of bystander signals of three earthworm species exposed in vivo was investigated: A. chlorotica, A. caliginosa, and E. tetraedra. Worms were exposed to external gamma irradiation (Co-60 source) for 24 h and samples of head, body, and clitellum were dissected from exposed and control worms and placed in culture medium for 24 h at 19 C. The harvested medium was filtered and assayed for expression of bystander signals using both clonogenic and mitochondrial reporter assays. Different responses were observed in the different species and in the different tissues. A. chlorotica worm-treated reporters show insignificant mitochondrial response for all sections, yet a significant clonogenic reduction in survival for body sections. A. caliginosa worm-treated reporters show a significant mitochondrial response for some sections and insignificant mitochondrial response and insignificant reduction in clonogenic survival for the rest. E. tetraedra worms from a control site show significant evidence of bystander signalling, measured by mitochondrial response in reporter cells, for all sections while those harvested from a contaminated site show insignificant changes in baseline signalling when exposed to the challenge dose. In vivo exposure of earthworm species shows evidence of bystander signalling using two different reporter assays. This effect varied between the different species and tissues. There is also evidence of attenuated bystander signalling in worms harvested from a site contaminated with radiation.
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Affiliation(s)
- Andrej Rusin
- Dept. of Biology, McMaster University, Hamilton, ON, Canada.
| | - Emmanuel Lapied
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, PO Box 5003, 1430 Aas, Norway
| | - Michelle Le
- Dept. of Biology, McMaster University, Hamilton, ON, Canada
| | - Colin Seymour
- Dept. of Biology, McMaster University, Hamilton, ON, Canada
| | - Deborah Oughton
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, PO Box 5003, 1430 Aas, Norway
| | - Hallvard Haanes
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, PO Box 5003, 1430 Aas, Norway; Norwegian Radiation Protection Authority (NRPA), Østerås, Norway
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Mothersill C, Rusin A, Fernandez-Palomo C, Seymour C. History of bystander effects research 1905-present; what is in a name? Int J Radiat Biol 2017; 94:696-707. [DOI: 10.1080/09553002.2017.1398436] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
| | - Andrej Rusin
- Department of Biology, McMaster University, Hamilton, Canada
| | | | - Colin Seymour
- Department of Biology, McMaster University, Hamilton, Canada
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12
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Mothersill C, Rusin A, Seymour C. Low doses and non-targeted effects in environmental radiation protection; where are we now and where should we go? ENVIRONMENTAL RESEARCH 2017; 159:484-490. [PMID: 28863303 DOI: 10.1016/j.envres.2017.08.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/12/2017] [Accepted: 08/14/2017] [Indexed: 06/07/2023]
Abstract
The field of low dose radiobiology has advanced considerably in the last 30 years from small indications in the 1980's that all was not simple, to a paradigm shift which occurred during the 1990's, which severely dented the dose-driven models and DNA centric theories which had dominated until then. However while the science has evolved, the application of that science in environmental health protection has not. A reason for this appears to be the uncertainties regarding the shape of the low dose response curve, which lead regulators to adopt a precautionary approach to radiation protection. Radiation protection models assume a linear relationship between dose (i.e. energy deposition) and effect (in this case probability of an adverse DNA interaction leading to a mutation). This model does not consider non-targeted effects (NTE) such as bystander effects or delayed effects, which occur in progeny cells or offspring not directly receiving energy deposition from the dose. There is huge controversy concerning the role of NTE with some saying they reflect "biology" and that repair and homeostatic mechanisms sort out the apparent damage while others consider them to be a class of damage which increases the size of the target. One thing which has recently become apparent is that NTE may be very critical for modelling long-term effects at the level of the population rather than the individual. The issue is that NTE resulting from an acute high dose such as occurred after the A-bomb or Chernobyl occur in parallel with chronic effects induced by the continuing residual effects due to radiation dose decay. This means that if ambient radiation doses are measured for example 25 years after the Chernobyl accident, they only represent a portion of the dose effect because the contribution of NTE is not included.
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Affiliation(s)
- Carmel Mothersill
- Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
| | - Andrej Rusin
- Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Colin Seymour
- Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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13
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Stuart M, Festarini A, Schleicher K, Tan E, Kim SB, Wen K, Gawlik J, Ulsh B. Biological effects of tritium on fish cells in the concentration range of international drinking water standards. Int J Radiat Biol 2016; 92:563-71. [DOI: 10.1080/09553002.2016.1222090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
| | - Amy Festarini
- Canadian Nuclear Laboratories (CNL), Chalk River, Canada
| | | | | | - Sang Bog Kim
- Canadian Nuclear Laboratories (CNL), Chalk River, Canada
| | - Kendall Wen
- Deep River Science Academy, Chalk River, Canada
| | | | - Brant Ulsh
- M. H. Chew & Associates, Inc., Cincinnati, OH, USA
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14
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Festarini A, Shultz C, Stuart M, Kim SB, Ferreri C. CELLULAR RESPONSES TO TRITIUM EXPOSURE IN RAINBOW TROUT: HTO- AND OBT-SPIKED FEED EXPOSURE EXPERIMENTS. CNL NUCLEAR REVIEW 2016. [DOI: 10.12943/cnr.2015.00059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Biological effects were evaluated in rainbow trout (Oncorhynchus mykiss) exposed to tritiated water (HTO) or food spiked with organically bound tritium (OBT). An HTO exposure study was conducted using a tritium activity concentration of 7000 Bq/L, and an OBT exposure study was conducted using a tritium activity concentration of 30 000 Bq/L. Following 140 days of in vivo HTO exposure, liver, heart, spleen, kidney, and brain cells did not show statistically significant differences in viability; kidney, liver, and spleen cells did not show significant differences in DNA double-strand break repair activity compared with control cells. Membrane fatty acid composition analysis was conducted on liver cells and no effects of HTO exposure could be detected. Following 140 days of in vivo OBT exposure, viability and DNA double-strand break repair activity were not statistically different from controls in liver, heart, spleen, kidney, and brain cells. Changes, however, were noted in the fatty acid composition of liver and muscle tissues. For both studies, all measurements were performed on each tissue and on a fraction of the same tissue that was exposed to a gamma 4 Gy dose in vitro to test for adaptive responses, and no effects were observed except for fatty acid composition. The findings demonstrated that membrane fatty acid composition is a sensitive marker and that microscopic evaluation of gamma-H2AX foci is more sensitive than the flow cytometric approach. These studies are the first to correlate uptake and depuration with biological health indicators in edible fish for tritium exposures within worldwide drinking water guidelines.
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Affiliation(s)
- Amy Festarini
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Carmen Shultz
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Marilyne Stuart
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Sang Bog Kim
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Carla Ferreri
- Department of Chemical Sciences and Materials Technologies of the National Research Council of Italy, Bologna, Italy
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Stark K, Scott DE, Tsyusko O, Coughlin DP, Hinton TG. Multi-Level Effects of Low Dose Rate Ionizing Radiation on Southern Toad, Anaxyrus [Bufo] terrestris. PLoS One 2015; 10:e0125327. [PMID: 25927361 PMCID: PMC4415799 DOI: 10.1371/journal.pone.0125327] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/13/2015] [Indexed: 11/18/2022] Open
Abstract
Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of 137Cs at 0.13, 2.4, 21, and 222 mGy d-1, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21 mGy d-1 and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.
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Affiliation(s)
- Karolina Stark
- Department of Ecology, Environment, and Plant Sciences, Stockholm University, Stockholm, Sweden
- Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, United States of America
- * E-mail:
| | - David E. Scott
- Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, United States of America
| | - Olga Tsyusko
- Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, United States of America
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, United States of America
| | - Daniel P. Coughlin
- Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, United States of America
| | - Thomas G. Hinton
- Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, United States of America
- Department of Radioecology, Environmental Modeling and Ecotoxicology, Institute of Radiation Protection and Nuclear Safety, Cadarache, France
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16
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Fernandez-Palomo C, Bräuer-Krisch E, Laissue J, Vukmirovic D, Blattmann H, Seymour C, Schültke E, Mothersill C. Use of synchrotron medical microbeam irradiation to investigate radiation-induced bystander and abscopal effects in vivo. Phys Med 2015; 31:584-95. [PMID: 25817634 DOI: 10.1016/j.ejmp.2015.03.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 01/01/2023] Open
Abstract
The question of whether bystander and abscopal effects are the same is unclear. Our experimental system enables us to address this question by allowing irradiated organisms to partner with unexposed individuals. Organs from both animals and appropriate sham and scatter dose controls are tested for expression of several endpoints such as calcium flux, role of 5HT, reporter assay cell death and proteomic profile. The results show that membrane related functions of calcium and 5HT are critical for true bystander effect expression. Our original inter-animal experiments used fish species whole body irradiated with low doses of X-rays, which prevented us from addressing the abscopal effect question. Data which are much more relevant in radiotherapy are now available for rats which received high dose local irradiation to the implanted right brain glioma. The data were generated using quasi-parallel microbeams at the biomedical beamline at the European Synchrotron Radiation Facility in Grenoble France. This means we can directly compare abscopal and "true" bystander effects in a rodent tumour model. Analysis of right brain hemisphere, left brain and urinary bladder in the directly irradiated animals and their unirradiated partners strongly suggests that bystander effects (in partner animals) are not the same as abscopal effects (in the irradiated animal). Furthermore, the presence of a tumour in the right brain alters the magnitude of both abscopal and bystander effects in the tissues from the directly irradiated animal and in the unirradiated partners which did not contain tumours, meaning the type of signal was different.
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Affiliation(s)
- Cristian Fernandez-Palomo
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
| | - Elke Bräuer-Krisch
- European Synchrotron Radiation Facility, BP 220 6, rue Jules Horowitz, 38043 Grenoble, France
| | - Jean Laissue
- University of Bern, Hochschulstrasse 4, CH-3012 Bern, Switzerland
| | - Dusan Vukmirovic
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | | | - Colin Seymour
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Elisabeth Schültke
- Department of Radiotherapy, Rostock University Medical Center, Südring 75, 18059 Rostock, Germany
| | - Carmel Mothersill
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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Kim SB, Shultz C, Stuart M, Festarini A. Tritium uptake in rainbow trout (Oncorhynchus mykiss): HTO and OBT-spiked feed exposures simultaneously. Appl Radiat Isot 2015; 98:96-102. [PMID: 25656986 DOI: 10.1016/j.apradiso.2015.01.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/09/2014] [Accepted: 01/20/2015] [Indexed: 11/27/2022]
Abstract
There is currently considerable interest in organically bound tritium (OBT) formation in edible fish. The major questions revolve around whether or not tritium can accumulate in fish after being released into aquatic environments. Since OBT formation rates in large, edible fish are poorly understood, rainbow trout (Oncorhynchus mykiss) studies, where fish were simultaneously exposed to tritiated water (HTO) and OBT-spiked feed over 130 days, were conducted to evaluate tritium uptake. The measured HTO activity concentrations in fish tissue confirmed that HTO in fish tissue equilibrates quickly with HTO in tank water. The data obtained also confirmed that OBT uptake is faster when fish are ingesting OBT-spiked feed compared to when fish are living in tritiated water (and consuming non-OBT-spiked feed). The difference between the two exposure types is such that the groups exposed to tritiated water and OBT-spiked feed simultaneously were showing the same uptake rates as OBT-spiked feed only exposures. Contrary to what was expected, the rate of OBT uptake (from OBT-spiked feed) seemed to be higher in slow growing fish compared to fast growing fish. Another observation from these studies was that OBT activity concentrations in all organs (viscera) had a tendency to be higher than OBT activity concentrations measured in fish flesh.
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Affiliation(s)
- S B Kim
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
| | - C Shultz
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
| | - M Stuart
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
| | - A Festarini
- Environmental Technologies Branch, Chalk River, Canadian Nuclear Laboratories, Canada K0J 1J0
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18
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Mothersill C, Smith R, Lariviere D, Seymour C. Chronic exposure by ingestion of environmentally relevant doses of (226)Ra leads to transient growth perturbations in fathead minnow (Pimephales promelas, Rafinesque, 1820). Int J Radiat Biol 2013; 89:950-64. [PMID: 23724911 DOI: 10.3109/09553002.2013.809817] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PURPOSE To assess the impact of environmentally relevant levels of ingested (226)Ra on a common freshwater fish species. METHODS Fathead minnow (Pimephales promelas, Rafinesque) were obtained at the first feeding stage and established on a commercial fish food diet containing (226)Ra in the activity range 10 mBq/g(-1), -10,000 mBq/g(-1). They remained on this diet for 24 months and were sampled invasively at 1,6,18 and 24 months to assess growth, biochemical indices and accumulated dose and non-invasively also at 12 and 15 months to assess growth. RESULTS Fish fed 10 and 100 mBq/g(-1) diet showed a small transitory deregulation of growth at 6 and 12 months. Fish fed higher activities showed less significant or insignificant effects. There was a trend at 18 months which was stronger at 24 months for the population distribution to change in all of the (226)Ra fed groups so that smaller fish were smaller and bigger fish were bigger than the controls. There were also significant differences in the ratios of protein:DNA at 24 months which were seen as a trend but were not significant at earlier time points. CONCLUSIONS Fish fed a radium diet for 2 years show a small and transitory growth dysregulation at 6 and 12 months. The effects predominate at the lower activities suggesting hormetic or homeostatic adjustments. There was no effect on growth of exposure to the high activities (226)Ra. This suggests that radium does not have a serious impact on the ecology of the system and the level of radium that would be transferred to humans is very low. The results may be important in the assessment of long-term environmental impacts of (226)Ra exposure.
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Affiliation(s)
- Carmel Mothersill
- Department of Medical Physics and Applied Radiation Sciences, McMaster University , Hamilton, Ontario
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19
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Mothersill C, Seymour C. Uncomfortable issues in radiation protection posed by low-dose radiobiology. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2013; 52:293-298. [PMID: 23673925 DOI: 10.1007/s00411-013-0472-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/27/2013] [Indexed: 06/02/2023]
Abstract
This paper aims to stimulate discussion about the relevance for radiation protection of recent findings in low-dose radiobiology. Issues are raised which suggest that low-dose effects are much more complex than has been previously assumed. These include genomic instability, bystander effects, multiple stressor exposures and chronic exposures. To date, these have been accepted as being relevant issues, but there is no clear way to integrate knowledge about these effects into the existing radiation protection framework. A further issue which might actually lead to some fruitful approaches for human radiation protection is the need to develop a new framework for protecting non-human biota. The brainstorming that is being applied to develop effective and practical ways to protect ecosystems widens the debate from the narrow focus of human protection which is currently about protecting humans from radiation-induced cancers.
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Affiliation(s)
- Carmel Mothersill
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada.
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20
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Ma S, Kong B, Liu B, Liu X. Biological effects of low-dose radiation from computed tomography scanning. Int J Radiat Biol 2013; 89:326-33. [PMID: 23216318 DOI: 10.3109/09553002.2013.756595] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE With the widespread use of computed tomography (CT), the risks of low-dose radiation from CT have been increasingly highlighted. This study aims to illustrate the CT-induced biological effects and analyze the potential beneficial or harmful outcomes so as to provide radiologists with reasonable advice on CT usage. MATERIALS AND METHODS The related literature was analyzed according to the topics of stochastic effect, hereditary effect, deterministic effect, accumulative injuries, hormesis and adaptive response; population epidemiology data were also analyzed. RESULTS CT accounts for 9% of X-ray examinations and approximately 40-67% of medical-related radiation, the dose is within the range of low-dose radiation (LDR). Two opposite viewpoints exist nowadays regarding the biological effects of CT scanning: They are either harmful or harmless. Approximately 0.6% and 1.5% of the cumulative cancer risk could be attributed to diagnostic X-rays in the UK and Germany, respectively. The probability of CT scans induced-cancer is about 0.7% and CT angiography's risk is around 0.13%. It is estimated that approximately 29,000 cancers could be related to CT scans in the USA every year. Meanwhile, another investigation of 25,104 patients who underwent 45,632 CT scans in 4 years showed that the majority of CT-induced cancers were accidents rather than certainties of frequent CT scans. CONCLUSION Although the LDR effects of CT are still controversial, the current problems include the high frequency-use and abuse of CT scans, the increase of radiation dose and accumulative dose in high-accuracy CT, and the poor understanding of carcinogenic risks. The underlying biological basis needs further exploring and the ratio of risks and benefits should be considered.
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Affiliation(s)
- Shumei Ma
- Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, Changchun, China
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21
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Kim SB, Shultz C, Stuart M, McNamara E, Festarini A, Bureau DP. Organically bound tritium (OBT) formation in rainbow trout (Oncorhynchus mykiss): HTO and OBT-spiked food exposure experiments. Appl Radiat Isot 2012. [PMID: 23208241 DOI: 10.1016/j.apradiso.2012.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In order to determine the rate of organically bound tritium (OBT) formation, rainbow trout (Oncorhynchus mykiss) were exposed to tritiated water (HTO) or OBT-spiked food. The HTO (in water) exposure study was conducted using a tritium activity concentration of approximately 7000 Bq/L and the OBT (in food) exposure study was conducted using a tritium activity concentration of approximately 30,000 Bq/L. Fish in both studies were expected to be exposed to similar tritium levels assuming 25% incorporation of the tritiated amino acids found in the food. Four different sampling campaigns of HTO exposure (Day 10, 30, 70, 140) and five different sampling campaigns of OBT-spiked food exposure (Day 9, 30, 70, 100, 140) were conducted to measure HTO and OBT activity concentrations in fish tissues. OBT depuration was also evaluated over a period of 30 days following the 140 d exposure studies. The results suggested that the OBT formation rate was slower when the fish were exposed to HTO compared to when the fish were ingesting OBT. In addition, the results indicated that OBT can bioaccumulate in fish tissues following OBT-spiked food exposure.
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Affiliation(s)
- S B Kim
- Environmental Technologies Branch, Chalk River Laboratories, AECL, Chalk River, Ontario, K0J 1J0 Canada.
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22
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Audette-Stuart M, Ferreri C, Festarini A, Carr J. Fatty Acid Composition of Muscle Tissue Measured in Amphibians Living in Radiologically Contaminated and Non-Contaminated Environments. Radiat Res 2012; 178:173-81. [DOI: 10.1667/rr2820.1] [Citation(s) in RCA: 10] [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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Abstract
In 2005, two expert advisory bodies examined the evidence on the effects of low doses of ionizing radiation. The U.S. National Research Council concluded that current scientific evidence is consistent with the linear no-threshold dose-response relationship (NRCNA 2005) while the French National Academies of Science and Medicine concluded the opposite (Aurengo et al. 2005). These contradictory conclusions may stem in part from an emphasis on epidemiological data (a "top down" approach) versus an emphasis on biological mechanisms (a "bottom up" approach). In this paper, the strengths and limitations of the top down and bottom up approaches are discussed, and proposals for strengthening and reconciling them are suggested. The past seven years since these two reports were published have yielded increasing evidence of nonlinear responses of biological systems to low radiation doses delivered at low dose-rates. This growing body of evidence is casting ever more doubt on the extrapolation of risks observed at high doses and dose-rates to estimate risks associated with typical environmental and occupational exposures. This paper compares current evidence on low dose, low dose-rate effects against objective criteria of causation. Finally, some questions for a post-LNT world are posed.
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