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Chaurasia RK, Sapra BK, Aswal DK. Interplay of immune modulation, adaptive response and hormesis: Suggestive of threshold for clinical manifestation of effects of ionizing radiation at low doses? THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170178. [PMID: 38280586 DOI: 10.1016/j.scitotenv.2024.170178] [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: 08/10/2023] [Revised: 12/26/2023] [Accepted: 01/13/2024] [Indexed: 01/29/2024]
Abstract
The health impacts of low-dose ionizing radiation exposures have been a subject of debate over the last three to four decades. While there has been enough evidence of "no adverse observable" health effects at low doses and low dose rates, the hypothesis of "Linear No Threshold" continues to rule and govern the principles of radiation protection and the formulation of regulations and public policies. In adopting this conservative approach, the role of the biological processes underway in the human body is kept at abeyance. This review consolidates the available studies that discuss all related biological pathways and repair mechanisms that inhibit the progression of deleterious effects at low doses and low dose rates of ionizing radiation. It is pertinent that, taking cognizance of these processes, there is a need to have a relook at policies of radiation protection, which as of now are too stringent, leading to undue economic losses and negative public perception about radiation.
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Affiliation(s)
- R K Chaurasia
- Radiological Physics and Advisory Division, India; Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
| | - B K Sapra
- Radiological Physics and Advisory Division, India; Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
| | - D K Aswal
- Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
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Little MP, Wakeford R, Zablotska LB, Borrego D, Griffin KT, Allodji RS, de Vathaire F, Lee C, Brenner AV, Miller JS, Campbell D, Pearce MS, Sadetzki S, Doody MM, Holmberg E, Lundell M, French B, Adams MJ, Berrington de González A, Linet MS. Radiation exposure and leukaemia risk among cohorts of persons exposed to low and moderate doses of external ionising radiation in childhood. Br J Cancer 2023; 129:1152-1165. [PMID: 37596407 PMCID: PMC10539334 DOI: 10.1038/s41416-023-02387-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/12/2023] [Accepted: 07/27/2023] [Indexed: 08/20/2023] Open
Abstract
BACKGROUND Many high-dose groups demonstrate increased leukaemia risks, with risk greatest following childhood exposure; risks at low/moderate doses are less clear. METHODS We conducted a pooled analysis of the major radiation-associated leukaemias (acute myeloid leukaemia (AML) with/without the inclusion of myelodysplastic syndrome (MDS), chronic myeloid leukaemia (CML), acute lymphoblastic leukaemia (ALL)) in ten childhood-exposed groups, including Japanese atomic bomb survivors, four therapeutically irradiated and five diagnostically exposed cohorts, a mixture of incidence and mortality data. Relative/absolute risk Poisson regression models were fitted. RESULTS Of 365 cases/deaths of leukaemias excluding chronic lymphocytic leukaemia, there were 272 AML/CML/ALL among 310,905 persons (7,641,362 person-years), with mean active bone marrow (ABM) dose of 0.11 Gy (range 0-5.95). We estimated significant (P < 0.005) linear excess relative risks/Gy (ERR/Gy) for: AML (n = 140) = 1.48 (95% CI 0.59-2.85), CML (n = 61) = 1.77 (95% CI 0.38-4.50), and ALL (n = 71) = 6.65 (95% CI 2.79-14.83). There is upward curvature in the dose response for ALL and AML over the full dose range, although at lower doses (<0.5 Gy) curvature for ALL is downwards. DISCUSSION We found increased ERR/Gy for all major types of radiation-associated leukaemia after childhood exposure to ABM doses that were predominantly (for 99%) <1 Gy, and consistent with our prior analysis focusing on <100 mGy.
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Affiliation(s)
- Mark P Little
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA.
| | - Richard Wakeford
- Centre for Occupational and Environmental Health, Faculty of Biology, Medicine and Health, The University of Manchester, Ellen Wilkinson Building, Oxford Road, Manchester, M13 9PL, UK
| | - Lydia B Zablotska
- Department of Epidemiology & Biostatistics, School of Medicine, University of California, San Francisco, 550 16th Street, 2nd floor, San Francisco, CA, 94143, USA
| | - David Borrego
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
| | - Keith T Griffin
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
| | - Rodrigue S Allodji
- Equipe d'Epidémiologie des radiations, Unité 1018 INSERM, Bâtiment B2M, Institut Gustave Roussy, Villejuif, Cedex, 94805, France
| | - Florent de Vathaire
- Equipe d'Epidémiologie des radiations, Unité 1018 INSERM, Bâtiment B2M, Institut Gustave Roussy, Villejuif, Cedex, 94805, France
| | - Choonsik Lee
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
| | - Alina V Brenner
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
| | - Jeremy S Miller
- Information Management Services, Silver Spring, MD, 20904, USA
| | - David Campbell
- Information Management Services, Silver Spring, MD, 20904, USA
| | - Mark S Pearce
- Institute of Health and Society, Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK
- NIHR Health Protection Research Unit in chemical and radiation threats and hazards, Newcastle University, Newcastle upon Tyne, UK
| | - Siegal Sadetzki
- Israel Ministry of Health, Jerusalem, Israel
- Cancer & Radiation Epidemiology Unit, Gertner Institute for Epidemiology & Health Policy Research, Sheba Medical Center, Tel-Hashomer, Israel & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Michele M Doody
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
| | - Erik Holmberg
- Department of Oncology, Sahlgrenska University Hospital, S-413-45, Göteborg, Sweden
| | - Marie Lundell
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, S-17176, Stockholm, Sweden
| | - Benjamin French
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael Jacob Adams
- University of Rochester School of Medicine and Dentistry, 265 Crittenden Boulevard, CU 420644, Rochester, NY, 14642-0644, USA
| | - Amy Berrington de González
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Martha S Linet
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD, 20892-9778, USA
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Jain V, Saini D, Soren DC, Kumar VA, Vivek Kumar PR, Koya PKM, Jaikrishan G, Das B. Non-linear dose response of DNA double strand breaks in response to chronic low dose radiation in individuals from high level natural radiation areas of Kerala coast. Genes Environ 2023; 45:16. [PMID: 37127760 PMCID: PMC10150514 DOI: 10.1186/s41021-023-00273-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND The human population living in high level natural radiation areas (HLNRAs) of Kerala coast provide unique opportunities to study the biological effects of low dose and low dose rate ionizing radiation below 100 mGy. The level of radiation in this area varies from < 1.0 to 45 mGy/year. The areas with ≤ 1.50 mGy/year are considered as normal level natural radiation areas (NLNRA) and > 1.50 mGy/year, as high level natural radiation areas (HLNRA). The present study evaluated dose response relationship between DNA double strand breaks (DSBs) and background radiation dose in individuals residing in Kerala coast. Venous blood samples were collected from 200 individuals belonging to NLNRA (n = 50) and four dose groups of HLNRA; 1.51-5.0 mGy/year (n = 50), 5.01-10.0 mGy/year (n = 30), 10.01-15.0 mGy/year (n = 33), > 15.0 mGy/year (n = 37) with written informed consent. The mean dose of NLNRA and four HLNRA dose groups studied are 1.21 ± 0.21 (range: 0.57-1.49), 3.02 ± 0.95 (range: 1.57-4.93), 7.43 ± 1.48 (range: 5.01-9.75), 12.22 ± 1.47 (range: 10.21-14.99), 21.64 ± 6.28 (range: 15.26-39.88) mGy/year, respectively. DNA DSBs were quantified using γH2AX as a marker, where foci were counted per cell using fluorescence microscopy. RESULTS Our results revealed that the frequency of γH2AX foci per cell was 0.090 ± 0.051 and 0.096 ± 0.051, respectively in NLNRA and HLNRA individuals, which were not significantly different (t198 = 0.33; P = 0.739). The frequency of γH2AX foci was observed to be 0.090 ± 0.051, 0.096 ± 0.051, 0.076 ± 0.036, 0.087 ± 0.042, 0.108 ± 0.046 per cell, respectively in different dose groups of ≤ 1.50, 1.51-5.0, 5.01-10.0, 10.01-15.0, > 15.0mGy/year (ANOVA, F4,195 = 2.18, P = 0.072) and suggested non-linearity in dose response. The frequency of γH2AX foci was observed to be 0.098 ± 0.042, 0.078 ± 0.037, 0.084 ± 0.042, 0.099 ± 0.058, 0.097 ± 0.06 and 0.114 ± 0.033 per cell in the age groups of ≤ 29, 30-34, 35-39, 40-44, 45-49 and ≥ 50 years, respectively (ANOVA, F5,194 = 2.17, P = 0.059), which suggested marginal influence of age on the baseline of DSBs. Personal habits such as smoking (No v/s Yes: 0.092 ± 0.047 v/s 0.093 ± 0.048, t198 = 0.13; P = 0.895) and drinking alcohol (No v/s Yes: 0.096 ± 0.052 v/s 0.091 ± 0.045, t198 = 0.62; P = 0.538) did not show any influence on DSBs in the population. CONCLUSION The present study did not show any increase in DSBs in different dose groups of HLNRA compared to NLNRA, however, it suggested a non-linear dose response between DNA DSBs and chronic low dose radiation.
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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - Divyalakshmi Saini
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - D C Soren
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - V Anil Kumar
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - P R Vivek Kumar
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - P K M Koya
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India.
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India.
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Otsuka K, Iwasaki T. Insights into radiation carcinogenesis based on dose-rate effects in tissue stem cells. Int J Radiat Biol 2023; 99:1503-1521. [PMID: 36971595 DOI: 10.1080/09553002.2023.2194398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 03/16/2023] [Indexed: 03/29/2023]
Abstract
PURPOSE Increasing epidemiological and biological evidence suggests that radiation exposure enhances cancer risk in a dose-dependent manner. This can be attributed to the 'dose-rate effect,' where the biological effect of low dose-rate radiation is lower than that of the same dose at a high dose-rate. This effect has been reported in epidemiological studies and experimental biology, although the underlying biological mechanisms are not completely understood. In this review, we aim to propose a suitable model for radiation carcinogenesis based on the dose-rate effect in tissue stem cells. METHODS We surveyed and summarized the latest studies on the mechanisms of carcinogenesis. Next, we summarized the radiosensitivity of intestinal stem cells and the role of dose-rate in the modulation of stem-cell dynamics after irradiation. RESULTS Consistently, driver mutations can be detected in most cancers from past to present, supporting the hypothesis that cancer progression is initiated by the accumulation of driver mutations. Recent reports demonstrated that driver mutations can be observed even in normal tissues, which suggests that the accumulation of mutations is a necessary condition for cancer progression. In addition, driver mutations in tissue stem cells can cause tumors, whereas they are not sufficient when they occur in non-stem cells. For non-stem cells, tissue remodeling induced by marked inflammation after the loss of tissue cells is important in addition to the accumulation of mutations. Therefore, the mechanism of carcinogenesis differs according to the cell type and magnitude of stress. In addition, our results indicated that non-irradiated stem cells tend to be eliminated from three-dimensional cultures of intestinal stem cells (organoids) composed of irradiated and non-irradiated stem cells, supporting the stem-cell competition. CONCLUSIONS We propose a unique scheme in which the dose-rate dependent response of intestinal stem cells incorporates the concept of the threshold of stem-cell competition and context-dependent target shift from stem cells to whole tissue. The concept highlights four key issues that should be considered in radiation carcinogenesis: i.e. accumulation of mutations; tissue reconstitution; stem-cell competition; and environmental factors like epigenetic modifications.
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Affiliation(s)
- Kensuke Otsuka
- Biology and Environmental Chemistry Division, Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry, Tokyo, Japan
| | - Toshiyasu Iwasaki
- Strategy and Planning Division, Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry, Tokyo, Japan
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Lowe D, Roy L, Tabocchini MA, Rühm W, Wakeford R, Woloschak GE, Laurier D. Radiation dose rate effects: what is new and what is needed? RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:507-543. [PMID: 36241855 PMCID: PMC9630203 DOI: 10.1007/s00411-022-00996-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/13/2022] [Indexed: 05/04/2023]
Abstract
Despite decades of research to understand the biological effects of ionising radiation, there is still much uncertainty over the role of dose rate. Motivated by a virtual workshop on the "Effects of spatial and temporal variation in dose delivery" organised in November 2020 by the Multidisciplinary Low Dose Initiative (MELODI), here, we review studies to date exploring dose rate effects, highlighting significant findings, recent advances and to provide perspective and recommendations for requirements and direction of future work. A comprehensive range of studies is considered, including molecular, cellular, animal, and human studies, with a focus on low linear-energy-transfer radiation exposure. Limits and advantages of each type of study are discussed, and a focus is made on future research needs.
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Affiliation(s)
- Donna Lowe
- UK Health Security Agency, CRCE Chilton, Didcot, OX11 0RQ, Oxfordshire, UK
| | - Laurence Roy
- Institut de Radioprotection Et de Sûreté Nucléaire, Fontenay-Aux-Roses, France
| | - Maria Antonella Tabocchini
- Istituto Nazionale i Fisica Nucleare, Sezione i Roma, Rome, Italy
- Istituto Superiore Di Sanità, Rome, Italy
| | - Werner Rühm
- Institute of Radiation Medicine, Helmholtz Center Munich, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Richard Wakeford
- Centre for Occupational and Environmental Health, The University of Manchester, Manchester, M13 9PL, UK
| | - Gayle E Woloschak
- Department of Radiation Oncology, Northwestern University School of Medicine, Chicago, IL, USA.
| | - Dominique Laurier
- Institut de Radioprotection Et de Sûreté Nucléaire, Fontenay-Aux-Roses, France
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JoJo P, Khandaker MU, Byju SB, Sunil A, Emran TB, Osman H, Almalki M, Alhumaydhi FA, Alghamdi S, Babalghith AO. Study of certain congenital malformations due to low-level radiation exposures from high background radiation areas. JOURNAL OF KING SAUD UNIVERSITY - SCIENCE 2022; 34:102166. [DOI: 10.1016/j.jksus.2022.102166] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Saini D, Jain V, Das B. Evaluation of natural chronic low dose radiation exposure on telomere length and transcriptional response of shelterin complex in individuals residing in Kerala coast, India. Mutat Res 2022; 825:111797. [PMID: 36116241 DOI: 10.1016/j.mrfmmm.2022.111797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/16/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
The high level natural radiation areas (HLNRA) of Kerala coast provide unique opportunity to study the biological effect of chronic low dose ionizing radiation (LDIR) on human population below 100 mSv. The radiation level in this area varies from < 1.0-45 mGy /year due to patchy distribution of monazite in the sand, which contains 232Th (8-10%), 238U (0.3%), and their decay products. Telomere length attrition has been correlated to DNA damage due to genotoxic agents. The objective of the present study is to evaluate the effect of natural chronic LDIR exposure on telomere length and transcriptional response of telomere specific and DNA damage repair genes in peripheral blood mononuclear cells (PBMCs) of individuals from normal level natural radiation areas (NLNRA) and HLNRA of Kerala coast, southwest India. Blood samples were collected from 71 random male donors (24-80 years) from NLNRA (≤1.50 mGy/year; N = 19) and two HLNRA dose groups [1.51-10 mGy/year (N = 17); > 10 mGy/year, (N = 35)]. Genomic DNA was isolated from PBMCs and relative telomere length (RTL) was determined using real time q-PCR. Radio-adaptive response (RAR) study was carried out in PBMCs of 40 random males from NLNRA (N = 20) and HLNRA (>10 mGy/year; N = 20), where PBMCs were given a challenged dose of 2.0 Gy gamma radiation at 4 h. Transcriptional profile of telomere specific (TRF1, TRF2, POT1, TIN2, TPP1, RAP1), DNA damage response (RAD17, ATM, CHEK1) and base excision repair pathway (BER) (OGG1, XRCC1, NTH1, NEIL1, MUTYH, MBD4) genes were analysed at basal level and after a challenge dose of 2.0 Gy at 4 h. Our results did not show any significant effect of chronic LDR on RTL among the individuals from NLNRA and two HLNRA groups (p = 0.195). However, influence of age on RTL was clearly evident among NLNRA and HLNRA individuals. At basal level, TRF1, TRF2, TIN2, MBD4, NEIL1 and RAD17 showed significant up-regulation, whereas XRCC1 was significantly down regulated in HLNRA individuals. After a challenge dose of 2.0 Gy, significant transcriptional up-regulation was observed at telomere specific (TRF2, POT1) and BER (MBD4, NEIL1) genes in HLNRA individuals as compared to NLNRA suggesting their role in RAR. In conclusion, elevated level of natural chronic LDR exposure did not have any adverse effect on telomere length in Kerala coast. Significant transcriptional response at TRF2, MBD4 and NEIL1 at basal level and with a challenge dose of 2.0 Gy suggested their active involvement in efficient repair and telomere maintenance in individuals from HLNRA of Kerala coast.
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Affiliation(s)
- Divyalakshmi Saini
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Mumbai University, Fort Mumbai, India
| | - Vinay Jain
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai 400 094, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Mumbai University, Fort Mumbai, India; Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai 400 094, India.
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Ghosh A. Biological and cellular responses of humans to high-level natural radiation: A clarion call for a fresh perspective on the linear no-threshold paradigm. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 878:503478. [PMID: 35649671 DOI: 10.1016/j.mrgentox.2022.503478] [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: 11/23/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 06/15/2023]
Abstract
There remains considerable uncertainty in obtaining risk estimates of adverse health outcomes of chronic low-dose radiation. In the absence of reliable direct data, extrapolation through the linear no-threshold (LNT) hypothesis forms the cardinal tenet of all risk assessments for low doses (≤ 100 mGy) and for the radiation protection principle of As Low As Reasonably Achievable (ALARA). However, as recent evidences demonstrate, LNT assumptions do not appropriately reflect the biology of the cell at the low-dose end of the dose-response curve. In this regard, human populations living in high-level natural radiation areas (HLNRA) of the world can provide valuable insights into the biological and cellular effects of chronic radiation to facilitate improved precision of the dose-response relationship at low doses. Here, data obtained over decades of epidemiological and radiobiological studies on HLNRA populations is summarized. These studies do not show any evidence of unfavourable health effects or adverse cellular effects that can be correlated with high-level natural radiation. Contrary to the assumptions of LNT, no excess cancer risks or untoward pregnancy outcomes have been found to be associated with cumulative radiation dose or in-utero exposures. Molecular biology-driven studies demonstrate that chronic low-dose activates several cellular defence mechanisms that help cells to sense, recover, survive, and adapt to radiation stress. These mechanisms include stress-response signaling, DNA repair, immune alterations and most importantly, the radiation-induced adaptive response. The HLNRA data is consistent with the new evolving paradigms of low-dose radiobiology and can help develop the theoretical framework of an alternate dose-response model. A rational integration of radiobiology with epidemiology data is imperative to reduce uncertainties in predicting the potential health risks of chronic low doses of radiation.
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Affiliation(s)
- Anu Ghosh
- Animal House Facility & Radiation Signaling Section, Radiation Biology & Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushaktinagar, Mumbai 400 094, India.
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9
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Chaudhury D, Sen U, Sahoo BK, Bhat NN, Kumara K S, Karunakara N, Biswas S, Shenoy P S, Bose B. Thorium promotes lung, liver and kidney damage in BALB/c mouse via alterations in antioxidant systems. Chem Biol Interact 2022; 363:109977. [DOI: 10.1016/j.cbi.2022.109977] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 01/15/2023]
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Fujimichi Y, Otsuka K, Tomita M, Iwasaki T. Ionizing radiation alters organoid forming potential and replenishment rate in a dose/dose-rate dependent manner. JOURNAL OF RADIATION RESEARCH 2022; 63:166-173. [PMID: 34977948 PMCID: PMC8944312 DOI: 10.1093/jrr/rrab120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/21/2021] [Indexed: 06/14/2023]
Abstract
Intestinal organoids are an in vitro cultured tissue model generated from intestinal stem cells, and they contain a mixture of epithelial cell types. We previously established an efficient 'one cell/well' sorting method, and defined organoid-forming potential (OFP) as a useful index to evaluate the stemness of individual cells. In this study, we assessed the response to radiation dose and dose-rate by measuring both OFP and the percentage of stem cells in the crypts. After high-dose-rate (HDR, 0.5 Gy/min) irradiation in vivo, the percentage of stem cells in the harvested crypt cells decreased, and the replenishment of cycling stem cells originating from dormant cells was enhanced, but OFP increased in cells irradiated with a total dose of >1 Gy. In contrast, at a total dose of 0.1 Gy the percentage of stem cells reduced slightly, but neither replenishment rate nor OFP changed. Furthermore, the response to 1 Gy of low-dose-rate (LDR) irradiation was similar to the response to 0.1 Gy HDR irradiation. These results suggest that 0.1 Gy HDR irradiation or 1 Gy LDR irradiation does not alter stemness. Additionally, the OFP increase in the colon in response to irradiation was smaller than that in the duodenum, similar to the percentage of stem cells. Understanding the differences in the response of stem cells between the colon and the duodenum to radiation is important to clarify the mechanisms underlying the development of radiation-associated intestinal cancers.
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Affiliation(s)
- Yuki Fujimichi
- Corresponding Author. Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado kita, Komae-shi, Tokyo 201-8511 Japan, Tel: +81-70-5457-2909 Fax: +81-3-3480-3113,
| | - Kensuke Otsuka
- Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado kita, Komae-shi, Tokyo 201-8511 Japan
| | - Masanori Tomita
- Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado kita, Komae-shi, Tokyo 201-8511 Japan
| | - Toshiyasu Iwasaki
- Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado kita, Komae-shi, Tokyo 201-8511 Japan
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Tanooka H. Radiation cancer risk at different dose rates: new dose-rate effectiveness factors derived from revised A-bomb radiation dosimetry data and non-tumor doses. JOURNAL OF RADIATION RESEARCH 2022; 63:1-7. [PMID: 34927198 PMCID: PMC8776691 DOI: 10.1093/jrr/rrab109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/14/2021] [Indexed: 06/14/2023]
Abstract
The dose rate of atomic bomb (A-bomb) radiation to the survivors has still remained unclear, although the dose-response data of A-bomb cancers has been taken as a standard in estimating the cancer risk of radiation and the dose and dose-rate effectiveness factor (DDREF). Since the applicability of the currently used DDREF of 2 derived from A-bomb data is limited in a narrow dose-rate range, 0.25-75 Gy/min as estimated from analysis of DS86 dosimetry data in the present study, a non-tumor dose (Dnt) was applied in an attempt to gain a more universal dose-rate effectiveness factor (DREF), where Dnt is an empirical parameter defined as the highest dose at which no statistically significant tumor increase is observed above the control level and its magnitude depends on the dose rate. The new DREF values were expressed as a function of the dose rate at four exposure categories, i.e. partial body low LET, whole body low linear energy transfer (LET), partial body high LET and whole body high LET and provided a value of 14 for environmental level radiation at a dose rate of 10-9 Gy/min for whole body low LET.
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Affiliation(s)
- Hiroshi Tanooka
- Corresponding author. National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. Tel. +81-3-3542-2511, Ext. 3224; Fax. +81-3-3542-0623; E-mail address:
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12
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Mahajan A, NiveditaChakrabarty, Shukla S. A narrative review on radiation risk from imaging for COVID-19: Breaking the myths and the mithya. CANCER RESEARCH, STATISTICS, AND TREATMENT 2022. [DOI: 10.4103/crst.crst_7_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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13
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Rühm W, Laurier D, Wakeford R. Cancer risk following low doses of ionising radiation - Current epidemiological evidence and implications for radiological protection. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 873:503436. [PMID: 35094811 DOI: 10.1016/j.mrgentox.2021.503436] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 01/05/2023]
Abstract
Recent studies suggest that every year worldwide about a million patients might be exposed to doses of the order of 100 mGy of low-LET radiation, due to recurrent application of radioimaging procedures. This paper presents a synthesis of recent epidemiological evidence on radiation-related cancer risks from low-LET radiation doses of this magnitude. Evidence from pooled analyses and meta-analyses also involving epidemiological studies that, individually, do not find statistically significant radiation-related cancer risks is reviewed, and evidence from additional and more recent epidemiological studies of radiation exposures indicating excess cancer risks is also summarized. Cohorts discussed in the present paper include Japanese atomic bomb survivors, nuclear workers, patients exposed for medical purposes, and populations exposed environmentally to natural background radiation or radioactive contamination. Taken together, the overall evidence summarized here is based on studies including several million individuals, many of them followed-up for more than half a century. In summary, substantial evidence was found from epidemiological studies of exposed groups of humans that ionizing radiation causes cancer at acute and protracted doses above 100 mGy, and growing evidence for doses below 100 mGy. The significant radiation-related solid cancer risks observed at doses of several 100 mGy of protracted exposures (observed, for example, among nuclear workers) demonstrate that doses accumulated over many years at low dose rates do cause stochastic health effects. On this basis, it can be concluded that doses of the order of 100 mGy from recurrent application of medical imaging procedures involving ionizing radiation are of concern, from the viewpoint of radiological protection.
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Affiliation(s)
- W Rühm
- Helmholtz Center Munich German Research Center for Environmental Health, Neuherberg, Germany.
| | - D Laurier
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Fontenay-aux-Roses, France
| | - R Wakeford
- Centre for Occupational and Environmental Health, The University of Manchester, Manchester, M13 9PL, UK
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14
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Omojola A, Ijabor B, Omojola F, Chukwueke F, Azuka P, Agama P, Okafor F. Radiological assessment of petroleum products in Aniocha South Local Government Area of Delta State, South-South Nigeria. RADIATION PROTECTION AND ENVIRONMENT 2022. [DOI: 10.4103/rpe.rpe_5_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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15
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Effect of X-ray exposure during hysterosalpingography on capabilities of female germ cells. J Assist Reprod Genet 2021; 38:3233-3242. [PMID: 34751833 DOI: 10.1007/s10815-021-02347-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 10/20/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To elucidate the effect of X-ray exposure during hysterosalpingography (HSG) on subsequent laboratory outcomes in in vitro fertilization (IVF). METHODS A total of 1458 oocytes, consisting of 990 oocytes retrieved from 70 women (89 cycles) who underwent HSG prior to IVF and 468 oocytes from 45 women (57 cycles) who underwent IVF without HSG, were evaluated for their retrieval number, maturity, fertilization, and development post fertilization. X-ray exposure during HSG was recorded as reference air kerma (RAK) (mGy). Subjects were stratified according to the amount of RAK (Nil: IVF without HSG, L-RAK: RAK < 16.23, mH-RAK: RAK ≥ 16.23). The number of oocytes retrieved, oocyte maturation, fertilization, and embryo development was compared among 3 groups. Further, multivariate analyses were performed to investigate the effect of X-ray exposure on laboratory outcomes in IVF. RESULTS There was a statistically significant difference in the fertilization rate among 3 groups (Nil: 71.6%, L-RAK: 80.5%, mH-RAK: 78.3%). The good-quality blastocyst rate in mH-RAK (46.2%) was significantly higher than L-RAK (35.3%) and Nil (32.4%). Multivariate analyses revealed that X-ray exposure was associated with higher fertilization, higher blastocyst development, and higher good-quality blastocyst development rates with adjustment for patient age, BMI, ovarian stimulation types, and fertilization methods. Association between X-ray exposure and the number of oocytes retrieved, and oocyte maturation was not confirmed. CONCLUSIONS The present study suggests that X-ray exposure of the female reproductive organs during HSG could enhance the potential of oocytes rather than adversely.
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16
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Priya R, Das B. Global DNA methylation profile at LINE-1 repeats and promoter methylation of genes involved in DNA damage response and repair pathways in human peripheral blood mononuclear cells in response to γ-radiation. Mol Cell Biochem 2021; 477:267-281. [PMID: 34708334 DOI: 10.1007/s11010-021-04265-4] [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] [Received: 04/04/2021] [Accepted: 09/17/2021] [Indexed: 02/02/2023]
Abstract
DNA methylation is an epigenetic mechanism, which plays an important role in gene regulation. The present study evaluated DNA methylation profile of LINE1 repeats and promoter methylation of DNA damage response (DDR) and DNA repair (DR) genes (PARP1, ATM, BRCA1, MLH1, XPC, RAD23B, APC, TNFα, DNMT3A, MRE11A, MGMT, CDKN2A, MTHFR) in human peripheral blood mononuclear cells (PBMCs) of healthy donors in response to γ-radiation. Methylation level was correlated with gene expression profile of selected DDR and DR genes (APC, MLH1, PARP1, MRE11A, TNFα, MGMT) to understand their role in gene regulation. Blood samples were collected from 15 random healthy donors, PBMCs were isolated, exposed to 0.1 Gy (low) and 2.0 Gy (high) doses of γ-radiation and proliferated for 48 h and 72 h. Genomic DNA and total RNA were isolated from irradiated PBMCs along with un-irradiated control. Methylation profile was determined from bisulphite converted DNA and amplified by methylation sensitive high resolution melting (MS-HRM) method. Total RNA was converted to cDNA and relative expression was analysed using real time quantitative-PCR. Our results revealed that at 0.1 Gy, MRE11A and TNFα showed significant (P < 0.05) increase in methylation at 72 h. At 2.0 Gy, significant increase (P < 0.05) in methylation profile was observed at LINE1, MRE11A, PARP1, BRCA1, DNMT3A and RAD23B at 48 h and 72 h. PARP1 showed significant positive correlation of methylation status with gene expression. In conclusion, low and high doses of γ-radiation have significant influence on DNA methylation status of LINE1, DDR and DR genes suggesting their potential role as epigenetic signatures in human PBMCs, which can be further explored in human populations.
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Affiliation(s)
- Rashmi Priya
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India. .,Homi Bhabha National Institute, Anushaktinagar, Trombay, Mumbai, 400 094, India.
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17
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Jayalekshmi PA, Nandakumar A, Nair RA, Akiba S, Koriyama C. Esophageal cancer in relation to alcohol drinking and tobacco use among men in Kerala, India - Karunagappally cohort. Cancer Epidemiol 2021; 74:102018. [PMID: 34507085 DOI: 10.1016/j.canep.2021.102018] [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] [Received: 05/11/2021] [Revised: 07/20/2021] [Accepted: 08/17/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND In the Karunagappally cohort, esophageal cancer is the third most common cancer with an age-adjusted incidence rate of 6.2 per 100,000 person-years among men. The present study analyzed the risk of esophageal cancer in relation to alcohol drinking and tobacco use. METHODS The study included 65,528 men aged 30-84 years in the Karunagappally cohort, India. RESULTS Poisson regression analysis showed that alcohol drinking significantly increased (P = 0.027) the risk of esophageal cancer and the relative risk (RR) for current drinkers was 1.6, (95 % confidence interval (CI) = 1.1-2.3). The risk increased significantly in heavy alcohol drinkers (250 g of ethanol or above per day) (RR = 2.1, 95 % CI = 1.2-3.5) (P for trend = 0.014) and among current arrack consumers (RR = 1.8, 95 % CI = 0.99-3.29) (P for trend = 0.025). Current bidi and cigarette smokers showed an increase in the trend of cancer risk. A significantly higher risk was seen in those who had started smoking bidi before the age of 18 years, RR = 1.9 (95 % CI = 1.1-3.3) (P for trend = 0.044). Furthermore, increased RR for heavy bidi and cigarette smokers were 1.6 (95 % CI = 1.1-2.5) and 2.4 (95 % CI = 1.3-4.5), respectively. CONCLUSION To the best of our knowledge, this is the first cohort study in India to report an increased esophageal cancer risk with respect to alcohol drinking.
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Affiliation(s)
- Padmavathy Amma Jayalekshmi
- Regional Cancer Center, Trivandrum, Kerala, India; Natural Background Radiation Cancer Registry, Karunagappally, Kerala, India.
| | - Athira Nandakumar
- Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Rekha A Nair
- Regional Cancer Center, Trivandrum, Kerala, India
| | - Suminori Akiba
- Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Chihaya Koriyama
- Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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18
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Walsh L, Shore R, Azizova TV, Rühm W. On the choice of methodology for evaluating dose-rate effects on radiation-related cancer risks. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2021; 60:493-500. [PMID: 34170393 PMCID: PMC8310494 DOI: 10.1007/s00411-021-00920-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/17/2021] [Indexed: 05/06/2023]
Abstract
Recently, several compilations of individual radiation epidemiology study results have aimed to obtain direct evidence on the magnitudes of dose-rate effects on radiation-related cancer risks. These compilations have relied on meta-analyses of ratios of risks from low dose-rate studies and matched risks from the solid cancer Excess Relative Risk models fitted to the acutely exposed Japanese A-bomb cohort. The purpose here is to demonstrate how choices of methodology for evaluating dose-rate effects on radiation-related cancer risks may influence the results reported for dose-rate effects. The current analysis is intended to address methodological issues and does not imply that the authors recommend a particular value for the dose and dose-rate effectiveness factor. A set of 22 results from one recent published study has been adopted here as a test set of data for applying the many different methods described here, that nearly all produced highly consistent results. Some recently voiced concerns, involving the recalling of the well-known theoretical point-the ratio of two normal random variables has a theoretically unbounded variance-that could potentially cause issues, are shown to be unfounded when aimed at the published work cited and examined in detail here. In the calculation of dose-rate effects for radiation protection purposes, it is recommended that meta-estimators should retain the full epidemiological and dosimetric matching information between the risks from the individual low dose-rate studies and the acutely exposed A-bomb cohort and that a regression approach can be considered as a useful alternative to current approaches.
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Affiliation(s)
- Linda Walsh
- Department of Physics, Science Faculty, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Roy Shore
- Department of Population Health, New York University Grossman School of Medicine, New York, USA
| | - Tamara V. Azizova
- Southern Urals Biophysics Institute, Ozyorskoe shosse 19, Ozyorsk, Chelyabinsk region 456780 Russia
| | - Werner Rühm
- Institute of Radiation Medicine, Helmholtz Zentrum München- German Research Center for Environmental Health, 85764 Neuherberg, Germany
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19
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Moorthy S. How Safe Are Radiation Doses in Diagnostic Radiology? A Historical Perspective and Review of Current Evidence. Indian J Radiol Imaging 2021; 31:653-660. [PMID: 34790311 PMCID: PMC8590548 DOI: 10.1055/s-0041-1735927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The "no dose is safe" linear no-threshold (LNT) model forms the basis for radiation safety in radiology practice. This model has its origins in observations of germline mutations in fruit flies exposed to X-rays. After World War II, quantitative risk estimates of radiation injury are primarily derived from the atomic bomb survivor Life Span Study. Current understanding of tissue response to radiation has raised doubts about the validity of LNT model at low doses encountered in the practice of diagnostic radiology. This article traces the evolution of basic radiation safety concepts and provides a bird's eye view of the Life Span Study and other studies which throw light on the matter. The arguments for an alternative, threshold, or even hermetic models of dose response are examined. The relevance of these developments to the nuclear power industry is also outlined.
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Affiliation(s)
- Srikanth Moorthy
- Department of Radiology, Amrita Institute of Medical Sciences and Research Centre, Amrita School of Medicine, Amrita Vishwa Vidyapeetham, Amrita Lane, Ponekkara, Kochi, Kerala, India
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20
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Shimura T. The role of mitochondrial oxidative stress and the tumor microenvironment in radiation-related cancer. JOURNAL OF RADIATION RESEARCH 2021; 62:i36-i43. [PMID: 33978176 PMCID: PMC8114220 DOI: 10.1093/jrr/rraa090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/21/2020] [Accepted: 06/23/2020] [Indexed: 05/15/2023]
Abstract
The health risks associated with low-dose radiation, which are a major concern after the Fukushima Daiichi nuclear power plant accident (the Fukushima accident), have been extensively investigated, and the cancer risks from low-dose radiation exposure (below ~ 100 mSv) are thought to be negligible. According to World Health Organization and the United Nations Scientific Committee on the Effects of Atomic Radiation reports, the level of radiation exposure from the Fukushima accident is limited, estimating no significant increased risk from the accident. Radiation-induced cell injury is mainly caused by oxidative damage to biomolecules, including DNA, lipids and proteins. Radiation stimulates metabolic activation within the mitochondria to provide energy for the DNA damage response. Mitochondrial respiratory chain complexes I and III are the most important intracellular source of reactive oxygen species (ROS) during oxidative phosphorylation in eukaryotic cells. Manganese superoxide dismutase and glutathione are key players in redox control within cells. However, perturbation of the antioxidant response leads to chronic oxidative stress in irradiated cells. Excess ROS of mitochondrial origin is reported in cancer-associated fibroblast and promotes carcinogenesis. The aim of this review paper is to discuss critical roles of mitochondria in radiation-related cancer by introducing our recent studies. In particular, elevated mitochondrial ROS in stromal fibroblasts potentiate transforming growth factor-beta (TGF-β) signaling, which triggers smooth muscle actin (α-SMA) expression to stimulate myofibroblast differentiation. Radiation-induced myofibroblasts promote tumor growth by enhancing angiogenesis. Thus, radiation affects both malignant cancer cells and neighboring stromal cells through secretion of soluble factors.
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Affiliation(s)
- Tsutomu Shimura
- Department of Environmental Health, National Institute of Public Health, Saitama, 351-0197, Japan
- Corresponding author. Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama 351-0197, Japan. Tel. +81-48-458-6261; Fax +81-48-458-6270;
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21
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Milder CM, Kendall GM, Arsham A, Schöllnberger H, Wakeford R, Cullings HM, Little MP. Summary of Radiation Research Society Online 66th Annual Meeting, Symposium on "Epidemiology: Updates on epidemiological low dose studies," including discussion. Int J Radiat Biol 2021; 97:866-873. [PMID: 33395353 DOI: 10.1080/09553002.2020.1867326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Cato M Milder
- Space Radiation Analysis Group, NASA Johnson Space Center, Houston, TX, USA
| | - Gerald M Kendall
- Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Headington, Oxford, UK
| | - Aryana Arsham
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD, USA
| | - Helmut Schöllnberger
- Department of Radiation Sciences, Institute of Radiation Medicine, Helmholtz Zentrum München, Neuherberg, Germany
| | - Richard Wakeford
- Centre for Occupational and Environmental Health, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Harry M Cullings
- Department of Statistics, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Mark P Little
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD, USA
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22
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Chronic exposure of humans to high level natural background radiation leads to robust expression of protective stress response proteins. Sci Rep 2021; 11:1777. [PMID: 33469066 PMCID: PMC7815775 DOI: 10.1038/s41598-020-80405-y] [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: 08/25/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022] Open
Abstract
Understanding exposures to low doses of ionizing radiation are relevant since most environmental, diagnostic radiology and occupational exposures lie in this region. However, the molecular mechanisms that drive cellular responses at these doses, and the subsequent health outcomes, remain unclear. A local monazite-rich high level natural radiation area (HLNRA) in the state of Kerala on the south-west coast of Indian subcontinent show radiation doses extending from ≤ 1 to ≥ 45 mGy/y and thus, serve as a model resource to understand low dose mechanisms directly on healthy humans. We performed quantitative discovery proteomics based on multiplexed isobaric tags (iTRAQ) coupled with LC–MS/MS on human peripheral blood mononuclear cells from HLNRA individuals. Several proteins involved in diverse biological processes such as DNA repair, RNA processing, chromatin modifications and cytoskeletal organization showed distinct expression in HLNRA individuals, suggestive of both recovery and adaptation to low dose radiation. In protein–protein interaction (PPI) networks, YWHAZ (14-3-3ζ) emerged as the top-most hub protein that may direct phosphorylation driven pro-survival cellular processes against radiation stress. PPI networks also identified an integral role for the cytoskeletal protein ACTB, signaling protein PRKACA; and the molecular chaperone HSPA8. The data will allow better integration of radiation biology and epidemiology for risk assessment [Data are available via ProteomeXchange with identifier PXD022380].
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Hosoda M, Nugraha ED, Akata N, Yamada R, Tamakuma Y, Sasaki M, Kelleher K, Yoshinaga S, Suzuki T, Rattanapongs CP, Furukawa M, Yamaguchi M, Iwaoka K, Sanada T, Miura T, Iskandar D, Pudjadi E, Kashiwakura I, Tokonami S. A unique high natural background radiation area - Dose assessment and perspectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:142346. [PMID: 33182182 DOI: 10.1016/j.scitotenv.2020.142346] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
The biological effects of low dose-rate radiation exposures on humans remains unknown. In fact, the Japanese nation still struggles with this issue after the Fukushima Dai-ichi Nuclear Power Plant accident. Recently, we have found a unique area in Indonesia where naturally high radiation levels are present, resulting in chronic low dose-rate radiation exposures. We aimed to estimate the comprehensive dose due to internal and external exposures at the particularly high natural radiation area, and to discuss the enhancement mechanism of radon. A car-borne survey was conducted to estimate the external doses from terrestrial radiation. Indoor radon measurements were made in 47 dwellings over three to five months, covering the two typical seasons, to estimate the internal doses. Atmospheric radon gases were simultaneously collected at several heights to evaluate the vertical distribution. The absorbed dose rates in air in the study area vary widely between 50 nGy h-1 and 1109 nGy h-1. Indoor radon concentrations ranged from 124 Bq m-3 to 1015 Bq m-3. That is, the indoor radon concentrations measured exceed the reference levels of 100 Bq m-3 recommended by the World Health Organization. Furthermore, the outdoor radon concentrations measured were comparable to the high indoor radon concentrations. The annual effective dose due to external and internal exposures in the study area was estimated to be 27 mSv using the median values. It was found that many residents are receiving radiation exposure from natural radionuclides over the dose limit for occupational exposure to radiation workers. This enhanced outdoor radon concentration might be as a result of the stable atmospheric conditions generated at an exceptionally low altitude. Our findings suggest that this area provides a unique opportunity to conduct an epidemiological study related to health effects due to chronic low dose-rate radiation exposure.
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Affiliation(s)
- Masahiro Hosoda
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Eka Djatnika Nugraha
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; Center for Technology of Radiation Safety and Metrology, National Nuclear Energy Agency, JI. Lebak Bulus Raya No. 49, Jakarta 12440, Indonesia
| | - Naofumi Akata
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Ryohei Yamada
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency, 4-33, Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194, Japan
| | - Yuki Tamakuma
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Michiya Sasaki
- Radiation Safety Research Center, Central Research Institute of Electric Power Industry, 2-11-1 Iwado kita, Komae, Tokyo 201-8511, Japan
| | - Kevin Kelleher
- Office of Radiation Protection and Environmental Monitoring, Environmental Protection Agency, Richview, Clonskeagh Road, Dublin 14, Ireland
| | - Shinji Yoshinaga
- Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Takahito Suzuki
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Chanis Pornnumpa Rattanapongs
- Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Lat Yao, Chatuchak, Bangkok 10900, Thailand
| | - Masahide Furukawa
- Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa 903-0213, Japan
| | - Masaru Yamaguchi
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Kazuki Iwaoka
- Center for Radiation Protection Knowledge, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Anagawa, Inage, Chiba 263-8555, Japan
| | - Tetsuya Sanada
- Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, 7-Jo 15-4-1 Maeda, Teine, Sapporo, Hokkaido 006-8585, Japan
| | - Tomisato Miura
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Dadong Iskandar
- Center for Technology of Radiation Safety and Metrology, National Nuclear Energy Agency, JI. Lebak Bulus Raya No. 49, Jakarta 12440, Indonesia
| | - Eko Pudjadi
- Center for Technology of Radiation Safety and Metrology, National Nuclear Energy Agency, JI. Lebak Bulus Raya No. 49, Jakarta 12440, Indonesia
| | - Ikuo Kashiwakura
- Depertment of Radiation Science, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
| | - Shinji Tokonami
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
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The Risk of Cancer from CT Scans and Other Sources of Low-Dose Radiation: A Critical Appraisal of Methodologic Quality. Prehosp Disaster Med 2020; 35:3-16. [PMID: 32009606 DOI: 10.1017/s1049023x1900520x] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Concern exists that radiation exposure from computerized tomography (CT) will cause thousands of malignancies. Other experts share the same perspective regarding the risk from additional sources of low-dose ionizing radiation, such as the releases from Three Mile Island (1979; Pennsylvania USA) and Fukushima (2011; Okuma, Fukushima Prefecture, Japan) nuclear power plant disasters. If this premise is false, the fear of cancer leading patients and physicians to avoid CT scans and disaster responders to initiate forced evacuations is unfounded. STUDY OBJECTIVE This investigation provides a quantitative evaluation of the methodologic quality of studies to determine the evidentiary strength supporting or refuting a causal relationship between low-dose radiation and cancer. It will assess the number of higher quality studies that support or question the role of low-dose radiation in oncogenesis. METHODS This investigation is a systematic, methodologic review of articles published from 1975-2017 examining cancer risk from external low-dose x-ray and gamma radiation, defined as less than 200 millisievert (mSv). Following the PRISMA guidelines, the authors performed a search of the PubMed, Cochrane, Scopus, and Web of Science databases. Methodologies of selected articles were scored using the Newcastle Ottawa Scale (NOS) and a tool identifying 11 lower quality indicators. Manuscript methodologies were ranked as higher quality if they scored no lower than seven out of nine on the NOS and contained no more than two lower quality indicators. Investigators then characterized articles as supporting or not supporting a causal relationship between low-dose radiation and cancer. RESULTS Investigators identified 4,382 articles for initial review. A total of 62 articles met all inclusion/exclusion criteria and were evaluated in this study. Quantitative evaluation of the manuscripts' methodologic strengths found 25 studies met higher quality criteria while 37 studies met lower quality criteria. Of the 25 studies with higher quality methods, 21 out of 25 did not support cancer induction by low-dose radiation (P = .0003). CONCLUSIONS A clear preponderance of articles with higher quality methods found no increased risk of cancer from low-dose radiation. The evidence suggests that exposure to multiple CT scans and other sources of low-dose radiation with a cumulative dose up to 100 mSv (approximately 10 scans), and possibly as high as 200 mSv (approximately 20 scans), does not increase cancer risk.
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Chaudhury D, Sen U, Bhat NN, Sahoo BK, Shenoy P S, Bose B. Lung damage by thoron progenies versus possible damage redemption by lung stem cells: a perspective. Int J Radiat Biol 2020; 96:1362-1373. [PMID: 32910703 DOI: 10.1080/09553002.2020.1820597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Natural radiation is the major source of human exposure to ionizing radiation. About 52% of the total dose received from the high natural background radiations (HNBR) areas are due to inhalation dose from radon (222Rn)/thoron (220Rn) and their progenies. Hence, we reviewed the biological effects of 222Rn/220Rn and their progenies on lung tissue, and the possible role of lung stem cells in salvaging the damage caused by 222Rn/220Rn and their progenies. MATERIALS AND METHOD We have extensively reviewed articles among several hits obtained in PubMed, Scopus, and Elsevier databases with keywords 'Radon/Thoron' OR Thoron progeny/Radon progeny OR 'Thoron/Radon inhalation and lungs', and proceed for further analysis. Also, databases related to oxidative damage to lung stem cells by radiation and the repair mechanisms involved by the lung stem cells were also included. RESULTS Based on the existing epidemiological data on radon in residential buildings, we found that evidence exists on the association of radon induced lung carcinogenesis, but the data regarding the role of thoron induced lung damage is very limited and inconclusive. We also found that limited information has been provided based on ecological designs, leading to poor documentation of health statistics, in particular, organ-specific cancer rates. Finally, we tried to elucidate the possible mechanisms of lung injury induced by thoron inhalation and the probable role of lung stem cell toward the redemption of such oxidative damages. CONCLUSION Existing epidemiological data on thoron inhalation and associated health outcomes are limited and inconclusive. Further, in vivo experiments, with respect to radon/thoron inhalation dose rate ranges corresponding to the HNBR areas will be helpful in understanding the cellular and molecular effects.
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Affiliation(s)
- Debajit Chaudhury
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Utsav Sen
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Nagesh N Bhat
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, India
| | - Bijay Kumar Sahoo
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, India
| | - Sudheer Shenoy P
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Bipasha Bose
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
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Abend M, Nisbet A, Gering F, Averin V, Andersson K, Schneider T, Mothersill C, Zeeb H, Scholz-Kreisel P, Yamashita S, Pölz-Viol C, Port M. "Living in Contaminated Areas"-Consideration of Different Perspectives. HEALTH PHYSICS 2020; 119:2-11. [PMID: 32205714 DOI: 10.1097/hp.0000000000001218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Following large-scale nuclear power plant accidents such as those that occurred at Chernobyl (Ukraine) in 1986 and Fukushima Daiichi (Japan) in 2011, large populations are living in areas containing residual amounts of radioactivity. As a key session of the ConRad conference, experts were invited from different disciplines to provide state-of-the-art information on the topic of "living in contaminated areas." These experts provided their different perspectives on a range of topics including radiation protection principles and dose criteria, environmental measurements and dose estimation, maintaining decent living and working conditions, evidence of health risks, and social impact and risk communication. A short summary of these different perspectives is provided in this paper.
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Affiliation(s)
- Michael Abend
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | - Anne Nisbet
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | - Florian Gering
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | - Viktor Averin
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | - Kasper Andersson
- Technical University of Denmark, DTU Environment, Radioecology and Tracer Studies Section, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Thierry Schneider
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | - Carmel Mothersill
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | - Hajo Zeeb
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
| | | | | | | | - Matthias Port
- Bundeswehr Institute of Radiobiology, Neuherberg str. 11, 80937 Munich
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Hauptmann M, Daniels RD, Cardis E, Cullings HM, Kendall G, Laurier D, Linet MS, Little MP, Lubin JH, Preston DL, Richardson DB, Stram DO, Thierry-Chef I, Schubauer-Berigan MK, Gilbert ES, Berrington de Gonzalez A. Epidemiological Studies of Low-Dose Ionizing Radiation and Cancer: Summary Bias Assessment and Meta-Analysis. J Natl Cancer Inst Monogr 2020; 2020:188-200. [PMID: 32657347 PMCID: PMC8454205 DOI: 10.1093/jncimonographs/lgaa010] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 03/26/2020] [Indexed: 07/27/2023] Open
Abstract
BACKGROUND Ionizing radiation is an established carcinogen, but risks from low-dose exposures are controversial. Since the Biological Effects of Ionizing Radiation VII review of the epidemiological data in 2006, many subsequent publications have reported excess cancer risks from low-dose exposures. Our aim was to systematically review these studies to assess the magnitude of the risk and whether the positive findings could be explained by biases. METHODS Eligible studies had mean cumulative doses of less than 100 mGy, individualized dose estimates, risk estimates, and confidence intervals (CI) for the dose-response and were published in 2006-2017. We summarized the evidence for bias (dose error, confounding, outcome ascertainment) and its likely direction for each study. We tested whether the median excess relative risk (ERR) per unit dose equals zero and assessed the impact of excluding positive studies with potential bias away from the null. We performed a meta-analysis to quantify the ERR and assess consistency across studies for all solid cancers and leukemia. RESULTS Of the 26 eligible studies, 8 concerned environmental, 4 medical, and 14 occupational exposure. For solid cancers, 16 of 22 studies reported positive ERRs per unit dose, and we rejected the hypothesis that the median ERR equals zero (P = .03). After exclusion of 4 positive studies with potential positive bias, 12 of 18 studies reported positive ERRs per unit dose (P = .12). For leukemia, 17 of 20 studies were positive, and we rejected the hypothesis that the median ERR per unit dose equals zero (P = .001), also after exclusion of 5 positive studies with potential positive bias (P = .02). For adulthood exposure, the meta-ERR at 100 mGy was 0.029 (95% CI = 0.011 to 0.047) for solid cancers and 0.16 (95% CI = 0.07 to 0.25) for leukemia. For childhood exposure, the meta-ERR at 100 mGy for leukemia was 2.84 (95% CI = 0.37 to 5.32); there were only two eligible studies of all solid cancers. CONCLUSIONS Our systematic assessments in this monograph showed that these new epidemiological studies are characterized by several limitations, but only a few positive studies were potentially biased away from the null. After exclusion of these studies, the majority of studies still reported positive risk estimates. We therefore conclude that these new epidemiological studies directly support excess cancer risks from low-dose ionizing radiation. Furthermore, the magnitude of the cancer risks from these low-dose radiation exposures was statistically compatible with the radiation dose-related cancer risks of the atomic bomb survivors.
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Affiliation(s)
- Michael Hauptmann
- Correspondence to: Michael Hauptmann, Institute of Biostatistics and Registry Research, Brandenburg Medical School Theodor Fontane. Fehrbelliner Straße 38, 16816 Neuruppin, Germany (e-mail: )
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Berrington de Gonzalez A, Daniels RD, Cardis E, Cullings HM, Gilbert E, Hauptmann M, Kendall G, Laurier D, Linet MS, Little MP, Lubin JH, Preston DL, Richardson DB, Stram D, Thierry-Chef I, Schubauer-Berigan MK. Epidemiological Studies of Low-Dose Ionizing Radiation and Cancer: Rationale and Framework for the Monograph and Overview of Eligible Studies. J Natl Cancer Inst Monogr 2020; 2020:97-113. [PMID: 32657348 PMCID: PMC7610154 DOI: 10.1093/jncimonographs/lgaa009] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/13/2020] [Indexed: 12/21/2022] Open
Abstract
Whether low-dose ionizing radiation can cause cancer is a critical and long-debated question in radiation protection. Since the Biological Effects of Ionizing Radiation report by the National Academies in 2006, new publications from large, well-powered epidemiological studies of low doses have reported positive dose-response relationships. It has been suggested, however, that biases could explain these findings. We conducted a systematic review of epidemiological studies with mean doses less than 100 mGy published 2006-2017. We required individualized doses and dose-response estimates with confidence intervals. We identified 26 eligible studies (eight environmental, four medical, and 14 occupational), including 91 000 solid cancers and 13 000 leukemias. Mean doses ranged from 0.1 to 82 mGy. The excess relative risk at 100 mGy was positive for 16 of 22 solid cancer studies and 17 of 20 leukemia studies. The aim of this monograph was to systematically review the potential biases in these studies (including dose uncertainty, confounding, and outcome misclassification) and to assess whether the subset of minimally biased studies provides evidence for cancer risks from low-dose radiation. Here, we describe the framework for the systematic bias review and provide an overview of the eligible studies.
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Affiliation(s)
| | - Robert D Daniels
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
| | - Elisabeth Cardis
- Barcelona Institute for Global Health (ISGlobal), Barcelona, Catalonia, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Ethel Gilbert
- Division of Cancer Epidemiology & Genetics, Radiation Epidemiology Branch, Bethesda, MD, USA
| | - Michael Hauptmann
- Department of Epidemiology and Biostatistics, Netherlands Cancer Institute, Amsterdam, the Netherlands
- Brandenburg Medical School Theodor Fontane, Institute of Biostatistics and Registry Research, Neuruppin, Germany
| | | | | | - Martha S Linet
- Division of Cancer Epidemiology & Genetics, Radiation Epidemiology Branch, Bethesda, MD, USA
| | - Mark P Little
- Division of Cancer Epidemiology & Genetics, Radiation Epidemiology Branch, Bethesda, MD, USA
| | - Jay H Lubin
- Division of Cancer Epidemiology & Genetics, Radiation Epidemiology Branch, Bethesda, MD, USA
| | | | | | - Daniel Stram
- University of Southern California, Los Angeles, CA
| | - Isabelle Thierry-Chef
- Barcelona Institute for Global Health (ISGlobal), Barcelona, Catalonia, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
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Wai KM, Krstic D, Nikezic D, Lin TH, Yu PKN. External Cesium-137 doses to humans from soil influenced by the Fukushima and Chernobyl nuclear power plants accidents: a comparative study. Sci Rep 2020; 10:7902. [PMID: 32404910 PMCID: PMC7220933 DOI: 10.1038/s41598-020-64812-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 04/21/2020] [Indexed: 11/24/2022] Open
Abstract
External exposure to gamma-photon irradiation from soil contamination due to nuclear power plant (NPP) accidents has significant contribution to human radiation exposure in the proximity of the NPP. Detailed absorbed doses in human organs are rarely reported in the literature. We applied the Monte Carlo Neutron Particle (MCNP) transport code to calculate and compare the absorbed doses in different human organs. The absorbed doses by gamma-photon radiation were from cesium-137 (137Cs) in soil contaminated by the two major NPP accidents. More serious and wide-spread impacts of the Chernobyl NPP accident on soil contamination in Ukraine, Belarus, Russia and countries as far as Sweden and Greece were due to the inland location, radiative plume transport pathway and high 137Cs emission strength (9 times the Fukushima emission). Based on our MCNP calculations, the largest absorbed dose was found in skin. The maximum calculated external 137Cs annual effective dose received from the Chernobyl accident was 10 times higher relative to the Fukushima accident. Our calculated effective doses at various influenced areas were comparable to those available in the literature. The calculated annual effective doses at areas near the Fukushima and Chernobyl NPPs exceeded the ICRP recommendation of 1 mSv yr-1.
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Affiliation(s)
- Ka-Ming Wai
- Department of Civil and Environmental Engineering, College of Engineering, Shantou University, Shantou, China.
- Intelligent Manufacturing Key Laboratory of Ministry of Education, Shantou University, Shantou, China.
| | - Dragana Krstic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, Kragujevac, 34000, Serbia
| | - Dragoslav Nikezic
- Faculty of Science, University of Kragujevac, R. Domanovica 12, Kragujevac, 34000, Serbia
| | - Tang-Huang Lin
- Center for Space and Remote Sensing Research, National Central University, Taoyuan City, Taiwan
| | - Peter K N Yu
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China.
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Inoue K, Sahoo SK, Veerasamy N, Kasahara S, Fukushi M. Distribution patterns of gamma radiation dose rate in the high background radiation area of Odisha, India. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07176-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Saini D, Sudheer KR, Kumar PRV, Soren DC, Jain V, Koya PKM, Jaikrishan G, Das B. Evaluation of the influence of chronic low-dose radiation on DNA repair gene polymorphisms [ XRCC1, XRCC3, PRKDC (XRCC7), LIG1, NEIL1] in individuals from normal and high level natural radiation areas of Kerala Coast. Int J Radiat Biol 2020; 96:734-739. [PMID: 32149571 DOI: 10.1080/09553002.2020.1739771] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background: Single Nucleotide Polymorphisms (SNPs) at DNA repair genes are considered as potential biomarkers of radio-sensitivity. The coastal belt of Kerala in south west India has a patchy distribution of monazite in its beach sand that contains Th-232 and its decay products. Thus, radiation levels in this area vary from <1.0mGy to 45.0mGy/year. The areas with external gamma radiation dose >1.5mGy/year are considered as High-Level Natural Radiation Areas (HLNRA) and ≤ 1.5mGy/year are Normal Level Natural Radiation Area (NLNRA).Objective: In the present study, an attempt was made to evaluate the influence of chronic low dose radiation exposure on DNA repair gene polymorphisms in NLNRA and HLNRA population of Kerala coast.Materials and methods: Genomic DNA was isolated from venous blood samples of 246 random, healthy individuals (NLNRA, N = 104; HLNRA, N = 142) and genotyping of five SNPs such as X-ray repair cross complementing 1(XRCC1 Arg399Gln), X-ray repair cross complementing 3 (XRCC3 Thr241Met], Protein kinase, DNA-activated, catalytic subunit (PRKDC) (X-ray repair cross-complementing group 7, XRCC7 G/T), nei like DNA glycosylase 1 (NEIL1 G/T) and DNA ligase 1 (LIG1 A/C) was carried out using PCR based restriction fragment length polymorphism (PCR-RFLP) followed by silver staining.Results: Our results showed no significant difference in genotype frequencies in HLNRA vs NLNRA at three of the five SNPs studied i.e. XRCC1 Arg399Gln (χ2(2) = 5.85, p = .054), XRCC3 Thr241Met (χ2(1) = 0.71, p = .339), PRKDC (XRCC7 G/T) (χ2(2) = 3.72, p = .156), whereas significant difference was observed at NEIL1 G/T (χ2(2) =8.71, p = .013) and LIG1 A/C (χ2(2) = 7.66, p = .022). The odds of heterozygote to homozygote genotypes in HLNRA relative to NLNRA at XRCC1 Arg399Gln (OR = 1.96, 95% CI: 1.13-3.40), XRCC3 Thr241Met (OR = 0.73, 95% CI: 0.41-1.31), PRKDC (XRCC7 G/T), (OR = 0.81; 95% CI: 0.48-1.38), NEIL1 G/T (OR = 0.54; 95% CI: 0.31-0.96) and LIG1 A/C (OR = 1.62; 95% CI: 0.97-2.69) was also not significantly different in HLNRA vs NLNRA, except at XRCC1 and NEIL1.Conclusion: The genotype frequencies at three of these SNPs i.e. XRCC1 Arg399Gln, XRCC3 Thr241Met and PRKDC (XRCC7 G/T) were similar, whereas NEIL1 G/T and LIG1 A/C showed significant difference between HLNRA and NLNRA population. However, further research using more number of SNPs in a larger cohort is required in this study area.
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Affiliation(s)
- Divyalakshmi Saini
- Low Level Radiation Research Section (LLRRS), Radiation Biology and Health Sciences Division (RB&HSD), Bhabha Atomic Research Centre, Mumbai, India
| | - K R Sudheer
- Low Level Radiation Research Laboratory (LLRRL), LLRRS, RB&HSD, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai, India
| | - P R Vivek Kumar
- Low Level Radiation Research Laboratory (LLRRL), LLRRS, RB&HSD, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai, India
| | - D C Soren
- Low Level Radiation Research Section (LLRRS), Radiation Biology and Health Sciences Division (RB&HSD), Bhabha Atomic Research Centre, Mumbai, India
| | - Vinay Jain
- Low Level Radiation Research Section (LLRRS), Radiation Biology and Health Sciences Division (RB&HSD), Bhabha Atomic Research Centre, Mumbai, India
| | - P K M Koya
- Low Level Radiation Research Laboratory (LLRRL), LLRRS, RB&HSD, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory (LLRRL), LLRRS, RB&HSD, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section (LLRRS), Radiation Biology and Health Sciences Division (RB&HSD), Bhabha Atomic Research Centre, Mumbai, India
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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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Nilsson R, Tong J. Opinion on reconsideration of lung cancer risk from domestic radon exposure. RADIATION MEDICINE AND PROTECTION 2020. [DOI: 10.1016/j.radmp.2020.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Rühm W, Breckow J, Dietze G, Friedl A, Greinert R, Jacob P, Kistinger S, Michel R, Müller WU, Otten H, Streffer C, Weiss W. Dose limits for occupational exposure to ionising radiation and genotoxic carcinogens: a German perspective. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:9-27. [PMID: 31677018 DOI: 10.1007/s00411-019-00817-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
This paper summarises the view of the German Commission on Radiological Protection ("Strahlenschutzkommission", SSK) on the rationale behind the currently valid dose limits and dose constraints for workers recommended by the International Commission on Radiological Protection (ICRP). The paper includes a discussion of the reasoning behind current dose limits followed by a discussion of the detriment used by ICRP as a measure for stochastic health effects. Studies on radiation-induced cancer are reviewed because this endpoint represents the most important contribution to detriment. Recent findings on radiation-induced circulatory disease that are currently not included in detriment calculation are also reviewed. It appeared that for detriment calculations the contribution of circulatory diseases plays only a secondary role, although the uncertainties involved in their risk estimates are considerable. These discussions are complemented by a review of the procedures currently in use in Germany, or in discussion elsewhere, to define limits for genotoxic carcinogens. To put these concepts in perspective, actual occupational radiation exposures are exemplified with data from Germany, for the year 2012, and regulations in Germany are compared to the recommendations issued by ICRP. Conclusions include, among others, considerations on radiation protection concepts currently in use and recommendations of the SSK on the limitation of annual effective dose and effective dose cumulated over a whole working life.
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Affiliation(s)
- Werner Rühm
- Helmholtz Zentrum München, Institute of Radiation Therapy, Ingolstädter Landstr. 1, 85764, Oberschleißheim, Germany.
| | | | - Günter Dietze
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - Anna Friedl
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | | | - Peter Jacob
- Helmholtz Zentrum München, Neuherberg, Germany
| | | | | | | | - Heinz Otten
- Deutsche Gesetzliche Unfallversicherung, Berlin, Germany
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Mishra K. Low-dose radiobiology: Opportunities for new research and technology for anticancer and anti-COVID-19 strategies. JOURNAL OF RADIATION AND CANCER RESEARCH 2020. [DOI: 10.4103/jrcr.jrcr_37_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Sreekumar A, Jayalekshmi PA, Nandakumar A, Nair RRK, Ahammed R, Sebastian P, Koriyama C, Akiba S, Nakamura S, Konishi J. Thyroid nodule prevalence among women in areas of high natural background radiation, Karunagappally, Kerala, India. Endocrine 2020; 67:124-130. [PMID: 31637657 DOI: 10.1007/s12020-019-02071-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/21/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE Radiation exposure has been reported to cause thyroid nodules. The study area was Karunagapally, which has several areas with high natural radiation levels derived from thorium and its decay products. Since thyroid abnormalities are more common in women, the focus was only on women. METHODS The examinations included interview, ultrasonography of the thyroid and serum assays of free thyroxine (FT4), thyrotropin (TSH), and anti-thyroglobulin levels. Cumulative dose during the childhood and lifetime cumulative dose (lagged by 5 years) were estimated. RESULTS We examined 524 female residents aged 17-73 years and found 75 cases of solitary solid thyroid nodules. The prevalence of thyroid nodules were 14.1 % (n = 42) in high dose panchayats and 14.5% (n = 33) in low-dose panchayats. In the logistic regression analysis adjusted for age, the prevalence of solitary thyroid nodule was not linearly related to childhood cumulative dose (P for trend = 0.159) and lifetime cumulative dose (P for trend = 0.333). The prevalence of thyroiditis and hypothyroidism was not related to natural radiation exposure. Serum levels of FT4 or TSH were not related to natural radiation exposure. CONCLUSIONS The results obtained from the present study do not support the increase of solitary thyroid nodule, thyroiditis or hypothyroidism in relation to high-natural-background-radiation exposure.
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Affiliation(s)
| | - Padmavathy Amma Jayalekshmi
- Regional Cancer Center Thiruvananthapuram, Thiruvananthapuram, Kerala, India
- Natural Background Radiation Cancer Registry, Karunagapally, Kerala, India
| | - Athira Nandakumar
- Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Korimoto, Kagoshima, 890-8580, Japan
| | - Raghu Ram K Nair
- Health Research Foundation, Research Institute for Production Development, Bldg.4F, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto, 606-0805, Japan
| | - Riyaz Ahammed
- Natural Background Radiation Cancer Registry, Karunagapally, Kerala, India
| | - Paul Sebastian
- Regional Cancer Center Thiruvananthapuram, Thiruvananthapuram, Kerala, India
| | - Chihaya Koriyama
- Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Korimoto, Kagoshima, 890-8580, Japan
| | - Suminori Akiba
- Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Korimoto, Kagoshima, 890-8580, Japan
- Health Research Foundation, Research Institute for Production Development, Bldg.4F, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto, 606-0805, Japan
| | - Seiichi Nakamura
- Health Research Foundation, Research Institute for Production Development, Bldg.4F, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto, 606-0805, Japan
| | - Junji Konishi
- Health Research Foundation, Research Institute for Production Development, Bldg.4F, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto, 606-0805, Japan
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Omori Y, Sorimachi A, Gun-Aajav M, Enkhgerel N, Munkherdene G, Oyunbolor G, Shajbalidir A, Palam E, Yamada C. Gamma dose rate distribution in the Unegt subbasin, a uranium deposit area in Dornogobi Province, southeastern Mongolia. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:33494-33506. [PMID: 31529344 DOI: 10.1007/s11356-019-06420-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Unegt subbasin in Dornogobi Province, southeastern Mongolia, contains the Dulaan Uul uranium deposit, for which development for commercial mining has been conducted as of 2015. Zuunbayan is a commune located close to the Dulaan Uul uranium deposit, and residents of Zuunbayan and their livestock can easily approach the uranium deposit area, including an aboveground dump site, which was created as a result of the mining development. The present study measured and analyzed the gamma dose rate (absorbed dose rate in air) distribution in Unegt subbasin using data collected from a car-borne measurement survey. The gamma dose rate increased from the northern (45-65 nGy/h) to the central (50-69 nGy/h, including Zuunbayan) and the southern (54-195 nGy/h, including Dulaan Uul) parts of the study area. The gamma dose rates (up to 195 nGy/h) around the dump site in Dulaan Uul were significantly higher than the background level (< 80 nGy/h) at several points. Additional in-situ measurements showed that the gamma dose rates reached up to 450 nGy/h at these locations, which was primarily attributed to the gamma radiation emitted by 238U series elements. Spatial distribution of gamma dose rates around the dump site revealed that the gamma radiation did not originate from the dump, but from the ground, at the measurement points. Analysis of collected soil samples showed that 238U and 226Ra were concentrated in deeper soil. These results indicate that the gamma dose rates higher than the background level were not associated with the aboveground mine dump; rather, they were very probably caused by presence of uranium deposits close to the ground surface.
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Affiliation(s)
- Yasutaka Omori
- Department of Radiation Physics and Chemistry, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
| | - Atsuyuki Sorimachi
- Department of Radiation Physics and Chemistry, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan
| | - Manlaijav Gun-Aajav
- The Executive Office of the Nuclear Energy Commission, Uildverchid Street 2, Khan Uul District, Ulaanbaatar, Mongolia
| | - Nyamdavaa Enkhgerel
- The Executive Office of the Nuclear Energy Commission, Uildverchid Street 2, Khan Uul District, Ulaanbaatar, Mongolia
| | - Ganbat Munkherdene
- The Executive Office of the Nuclear Energy Commission, Uildverchid Street 2, Khan Uul District, Ulaanbaatar, Mongolia
| | - Galnemekh Oyunbolor
- The Executive Office of the Nuclear Energy Commission, Uildverchid Street 2, Khan Uul District, Ulaanbaatar, Mongolia
| | - Amarbileg Shajbalidir
- Center for Hydrology, Meteorology and Environmental Monitoring of Dornogobi Province, Sainshand, Dornogobi, Mongolia
| | - Enkhtuya Palam
- National Center for Public Health, Ministry of Health, 17 Peace Avenue, Ulaanbaatar, Mongolia
| | - Chieri Yamada
- Department of Public Health Nursing for International Radiation Exposure, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan
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Lampe N, Marin P, Coulon M, Micheau P, Maigne L, Sarramia D, Piquemal F, Incerti S, Biron DG, Ghio C, Sime-Ngando T, Hindre T, Breton V. Reducing the ionizing radiation background does not significantly affect the evolution of Escherichia coli populations over 500 generations. Sci Rep 2019; 9:14891. [PMID: 31624294 PMCID: PMC6797783 DOI: 10.1038/s41598-019-51519-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 09/30/2019] [Indexed: 12/31/2022] Open
Abstract
Over millennia, life has been exposed to ionizing radiation from cosmic rays and natural radioisotopes. Biological experiments in underground laboratories have recently demonstrated that the contemporary terrestrial radiation background impacts the physiology of living organisms, yet the evolutionary consequences of this biological stress have not been investigated. Explaining the mechanisms that give rise to the results of underground biological experiments remains difficult, and it has been speculated that hereditary mechanisms may be involved. Here, we have used evolution experiments in standard and very low-radiation backgrounds to demonstrate that environmental ionizing radiation does not significantly impact the evolutionary trajectories of E. coli bacterial populations in a 500 generations evolution experiment.
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Affiliation(s)
- Nathanael Lampe
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
| | - Pierre Marin
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
| | - Marianne Coulon
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
| | - Pierre Micheau
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
| | - Lydia Maigne
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
| | - David Sarramia
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
| | - Fabrice Piquemal
- Laboratoire Souterrain de Modane, 1125 Route de Bardonèche, F-73500, Modane, France.,Université de Bordeaux, CNRS/IN2P3, CENBG, F-33170, Gradignan, France
| | - Sébastien Incerti
- Université de Bordeaux, CNRS/IN2P3, CENBG, F-33170, Gradignan, France
| | - David G Biron
- CNRS UMR 6023, Université Clermont-Auvergne, Laboratoire "Microorganismes: Génome et Environnement" (LMGE), F-63000, Clermont-Ferrand, France
| | - Camille Ghio
- CNRS UMR 6023, Université Clermont-Auvergne, Laboratoire "Microorganismes: Génome et Environnement" (LMGE), F-63000, Clermont-Ferrand, France
| | - Télesphore Sime-Ngando
- CNRS UMR 6023, Université Clermont-Auvergne, Laboratoire "Microorganismes: Génome et Environnement" (LMGE), F-63000, Clermont-Ferrand, France
| | - Thomas Hindre
- Univ. Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, F-38000, Grenoble, France.
| | - Vincent Breton
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000, Clermont-Ferrand, France
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Leblanc JE, Burtt JJ. Radiation Biology and Its Role in the Canadian Radiation Protection Framework. HEALTH PHYSICS 2019; 117:319-329. [PMID: 30907783 DOI: 10.1097/hp.0000000000001060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The linear no-threshold (linear-non-threshold) model is a dose-response model that has long served as the foundation of the international radiation protection framework, which includes the Canadian regulatory framework. Its purpose is to inform the choice of appropriate dose limits and subsequent as low as reasonably achievable requirements, social and economic factors taken into account. The linear no-threshold model assumes that the risk of developing cancer increases proportionately with increasing radiation dose. The linear no-threshold model has historically been applied by extrapolating the risk of cancer at high doses (>1,000 mSv) down to low doses in a linear manner. As the health effects of radiation exposure at low doses remain ambiguous, reducing uncertainties found in cancer risk dose-response models can be achieved through in vitro and animal-based studies. The purpose of this critical review is to analyze whether the linear no-threshold model is still applicable for use by modern nuclear regulators for radiation protection purposes, or if there is sufficient scientific evidence supporting an alternate model from which to derive regulatory dose limits.
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40
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A Critical Assessment of the Linear No-Threshold Hypothesis: Its Validity and Applicability for Use in Risk Assessment and Radiation Protection. Clin Nucl Med 2019; 44:521-525. [PMID: 31107746 DOI: 10.1097/rlu.0000000000002613] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The Society of Nuclear Medicine and Molecular Imaging convened a task group to examine the evidence for the risk of carcinogenesis from low-dose radiation exposure and to assess evidence in the scientific literature related to the overall validity of the linear no-threshold (LNT) hypothesis and its applicability for use in risk assessment and radiation protection. In the low-dose and dose-rate region, the group concluded that the LNT hypothesis is invalid as it is not supported by the available scientific evidence and, instead, is actually refuted by published epidemiology and radiation biology. The task group concluded that the evidence does not support the use of LNT either for risk assessment or radiation protection in the low-dose and dose-rate region.
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Boice JD, Held KD, Shore RE. Radiation epidemiology and health effects following low-level radiation exposure. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:S14-S27. [PMID: 31272090 DOI: 10.1088/1361-6498/ab2f3d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Radiation epidemiology is the study of human disease following radiation exposure to populations. Epidemiologic studies of radiation-exposed populations have been conducted for nearly 100 years, starting with the radium dial painters in the 1920s and most recently with large-scale studies of radiation workers. As radiation epidemiology has become increasingly sophisticated it is used for setting radiation protection standards as well as to guide the compensation programmes in place for nuclear weapons workers, nuclear weapons test participants, and other occupationally exposed workers in the United States and elsewhere. It is known with high assurance that radiation effects at levels above 100-150 mGy can be detected as evidenced in multiple population studies conducted around the world. The challenge for radiation epidemiology is evaluating the effects at low doses, below about 100 mGy of low-linear energy transfer radiation, and assessing the risks following low dose-rate exposures over years. The weakness of radiation epidemiology in directly studying low dose and low dose-rate exposures is that the signal, i.e. the excess numbers of cancers associated with low-level radiation exposure, is so very small that it cannot be seen against the very high background occurrence of cancer in the population, i.e. a lifetime risk of incidence reaching up to about 38% (i.e. 1 in 3 persons will develop a cancer in their lifetime). Thus, extrapolation models are used for the management of risk at low doses and low dose rates, but having adequate information from low dose and low dose-rate studies would be highly desirable. An overview of recently conducted radiation epidemiologic studies which evaluate risk following low-level radiation exposures is presented. Future improvements in risk assessment for radiation protection may come from increasingly informative epidemiologic studies, combined with mechanistic radiobiologic understanding of adverse outcome pathways, with both incorporated into biologically based models.
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Affiliation(s)
- J D Boice
- National Council on Radiation Protection and Measurements, Bethesda, Maryland, United States of America. Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
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42
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Sasaki M, Kudo S, Furuta H. Effect of Radiation Dose Rate on Cancer Mortality among Nuclear Workers: Reanalysis of Hanford Data. HEALTH PHYSICS 2019; 117:13-19. [PMID: 31136363 DOI: 10.1097/hp.0000000000001039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The excess relative risk of mortality for all cancers excluding leukemia among nuclear workers was reanalyzed by taking the annual dose as the dose rate into consideration using publicly available epidemiological data from the Hanford site dedicated to the cohort study of nuclear workers in the United States, the United Kingdom, and Canada (Three Countries Study). Values of the dose rate (cut points) were chosen at 2 mSv y intervals from 2 to 40 mSv y, and risk estimates were made for 32,988 workers, considering doses accumulated below the cut point and above the cut point to have different effects. Although the procedure to extract the study population and the methodology used for analysis basically followed those in the Three Countries Study, additional examinations were also carried out for different risk models, lag periods, and impacts of adjusting the monitoring period to find the effect of the dose rate. As a result, no statistically significant difference in dose rate was found among the excess relative risks under different calculation conditions.
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Affiliation(s)
- Michiya Sasaki
- Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry, Tokyo, Japan
| | - Shin'ichi Kudo
- Institute of Radiation Epidemiology, Radiation Effects Association, Tokyo, Japan
| | - Hiroshige Furuta
- Institute of Radiation Epidemiology, Radiation Effects Association, Tokyo, Japan
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43
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S M J M, Gh M, S A R M, M P. Is Induction of Anomalies in Lymphocytes of the Residents of High Background Radiation Areas Associated with Increased Cancer Risk? J Biomed Phys Eng 2019; 9:367-372. [PMID: 31341882 PMCID: PMC6613150 DOI: 10.31661/jbpe.v9i3jun.654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022]
Abstract
Man has been exposed to different levels of natural background radiation since the creation of human life. There are inhabited areas around the world with extraordinary levels of natural background radiation. The level of natural radiation in these areas is up to two orders of magnitude higher than other places. Areas such as Yangjiang, China; Guarapari, Brazil; and Kerala, India are among the areas with high levels of natural radiation. Ramsar a coastal city in North Iran has some inhabited areas with the highest known levels of background radiation around the world. People who live in high background radiation areas (HBRAs) such as Ramsar do not record any detrimental biological effects. While some cytogenetic studies conducted in HBRAs have shown increased frequencies of unstable chromosome aberration, other investigations failed to find a significant difference. This short review is an attempt to verify if induction of chromosomal anomalies in the lymphocytes of the residents of high background radiation areas is associated with increased cancer risk.
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Affiliation(s)
- Mortazavi S M J
- Professor of Medical Physics, Medical Physics Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mortazavi Gh
- Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mortazavi S A R
- Student of Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Paknahad M
- Oral and Dental Disease Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
- Assistant Professor of Oral and Maxillofacial Radiology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
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44
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Distribution of natural radionuclides and assessment of excess lifetime cancer risk along coastal areas of Varkala in Kerala. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06509-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Shore RE, Beck HL, Boice JD, Caffrey EA, Davis S, Grogan HA, Mettler FA, Preston RJ, Till JE, Wakeford R, Walsh L, Dauer LT. Recent Epidemiologic Studies and the Linear No-Threshold Model For Radiation Protection-Considerations Regarding NCRP Commentary 27. HEALTH PHYSICS 2019; 116:235-246. [PMID: 30585971 DOI: 10.1097/hp.0000000000001015] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
National Council on Radiation Protection and Measurements Commentary 27 examines recent epidemiologic data primarily from low-dose or low dose-rate studies of low linear-energy-transfer radiation and cancer to assess whether they support the linear no-threshold model as used in radiation protection. The commentary provides a critical review of low-dose or low dose-rate studies, most published within the last 10 y, that are applicable to current occupational, environmental, and medical radiation exposures. The strengths and weaknesses of the epidemiologic methods, dosimetry assessments, and statistical modeling of 29 epidemiologic studies of total solid cancer, leukemia, breast cancer, and thyroid cancer, as well as heritable effects and a few nonmalignant conditions, were evaluated. An appraisal of the degree to which the low-dose or low dose-rate studies supported a linear no-threshold model for radiation protection or on the contrary, demonstrated sufficient evidence that the linear no-threshold model is inappropriate for the purposes of radiation protection was also included. The review found that many, though not all, studies of solid cancer supported the continued use of the linear no-threshold model in radiation protection. Evaluations of the principal studies of leukemia and low-dose or low dose-rate radiation exposure also lent support for the linear no-threshold model as used in protection. Ischemic heart disease, a major type of cardiovascular disease, was examined briefly, but the results of recent studies were considered too weak or inconsistent to allow firm conclusions regarding support of the linear no-threshold model. It is acknowledged that the possible risks from very low doses of low linear-energy-transfer radiation are small and uncertain and that it may never be possible to prove or disprove the validity of the linear no-threshold assumption by epidemiologic means. Nonetheless, the preponderance of recent epidemiologic data on solid cancer is supportive of the continued use of the linear no-threshold model for the purposes of radiation protection. This conclusion is in accord with judgments by other national and international scientific committees, based on somewhat older data. Currently, no alternative dose-response relationship appears more pragmatic or prudent for radiation protection purposes than the linear no-threshold model.
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Affiliation(s)
- Roy E Shore
- New York University School of Medicine, New York, NY, and Radiation Effects Research Foundation, Hiroshima, Japan (retired)
| | | | - John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, and Vanderbilt University, Nashville, TN
| | | | - Scott Davis
- Fred Hutchinson Cancer Research Center, Seattle, WA
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46
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Held K. NCRP 54th Annual Meeting, Radiation Protection Responsibility in Medicine: Tenforde Topical Lecture and Fostering Innovations Q & A (Questions for Roy E. Shore [T.S. Tenforde Lecturer], Ehsan Samei, Keith J. Strauss, and X. George Xu). HEALTH PHYSICS 2019; 116:276-278. [PMID: 30585975 DOI: 10.1097/hp.0000000000001021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Kathryn Held
- NCRP, 7910 Woodmont Avenue, Suite 400, Bethesda, MD 20814
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47
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Obodovskiy I. Residents of Areas With High Natural Background Radiation. RADIATION 2019. [DOI: 10.1016/b978-0-444-63979-0.00053-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Imaoka T, Nishimura M, Daino K, Hosoki A, Takabatake M, Nishimura Y, Kokubo T, Morioka T, Doi K, Shimada Y, Kakinuma S. Prominent Dose-Rate Effect and Its Age Dependence of Rat Mammary Carcinogenesis Induced by Continuous Gamma-Ray Exposure. Radiat Res 2018; 191:245-254. [PMID: 30543491 DOI: 10.1667/rr15094.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although the risk of breast cancer after high-dose-rate irradiation has been firmly established, however, the risk incurred for low-dose-rate irradiation is not well understood. Here we provide experimental evidence for dose rate and age dependencies induced by continuous γ-ray irradiation on mammary carcinogenesis. Female rats received continuous whole-body irradiation at one of the following time points: at 7 weeks of age (denoted adults) at a dose rate of 3-60 mGy/h (4 Gy total); or at either 3 weeks (denoted juveniles) or 7 weeks of age at a dose rate of 6 mGy/h (1-8 Gy total). Additional rats were acutely irradiated at 13 weeks of age at a dose rate of 30 Gy/h (0.5-4 Gy total). We observed the incidence of mammary tumors by weekly palpation until they were 90 weeks old and after pathological inspection upon autopsy. The tumor incidence rate for each group was characterized by Cox regression analysis. When adult rats were irradiated at 60 mGy/h for a total of 4 Gy, their hazard ratio for mammary carcinoma significantly increased relative to nonirradiated controls; however, for adult rats irradiated at 3-24 mGy/h, even though they also received a total of 4 Gy, their hazard ratio for carcinoma incidence did not significantly increase. A larger increase in the incidence rate of carcinoma per dose was found for the juveniles than for the adults irradiated at 6 mGy/h, whereas age did not influence the effect of acute irradiation at 30 Gy/h; a threshold-like dose response was observed for irradiation at 6 mGy/h (threshold, ∼2.5 and ∼4 Gy for juveniles and adults, respectively). Regarding benign tumors of the mammary gland, a significant increase in their incidence was observed for irradiation down to 6 mGy/h, but not at 3 mGy/h and there was no evidence of age-dependent induction. Thus, induction of female rat mammary carcinogenesis by continuous γ-ray exposure was age dependent and drastically increased for adult rats that received between 24 and 60 mGy/h irradiation.
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Affiliation(s)
- Tatsuhiko Imaoka
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,d QST Advanced Study Laboratory, QST, Chiba, Japan.,e Tokyo Metropolitan University, Tokyo, Japan
| | - Mayumi Nishimura
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Kazuhiro Daino
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Ayaka Hosoki
- f Fukushima Project Headquarters, NIRS, Chiba, Japan
| | - Masaru Takabatake
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,e Tokyo Metropolitan University, Tokyo, Japan
| | - Yukiko Nishimura
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Toshiaki Kokubo
- b Department of Engineering and Safety, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Takamitsu Morioka
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Kazutaka Doi
- c Center for Radiation Protection Knowledge, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Yoshiya Shimada
- e Tokyo Metropolitan University, Tokyo, Japan.,g Executive Director, QST, Chiba, Japan
| | - Shizuko Kakinuma
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
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Nishad S, Ghosh A. Comparative proteomic analysis of human peripheral blood mononuclear cells indicates adaptive response to low-dose radiation in individuals from high background radiation areas of Kerala. Mutagenesis 2018; 33:359-370. [DOI: 10.1093/mutage/gey036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/25/2018] [Indexed: 12/11/2022] Open
Affiliation(s)
- Srambikkal Nishad
- Radiation Signaling Group, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
- Homi Bhabha National Institute, Mumbai, India
| | - Anu Ghosh
- Radiation Signaling Group, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
- Homi Bhabha National Institute, Mumbai, India
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Kendall GM, Chernyavskiy P, Appleton JD, Miles JCH, Wakeford R, Athanson M, Vincent TJ, McColl NP, Little MP. Modelling the bimodal distribution of indoor gamma-ray dose-rates in Great Britain. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2018; 57:321-347. [PMID: 30132159 DOI: 10.1007/s00411-018-0752-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 08/04/2018] [Indexed: 06/08/2023]
Abstract
Gamma radiation from naturally occurring sources (including directly ionizing cosmic-rays) is a major component of background radiation. An understanding of the magnitude and variation of doses from these sources is important, and the ability to predict them is required for epidemiological studies. In the present paper, indoor measurements of naturally occurring gamma-rays at representative locations in Great Britain are summarized. It is shown that, although the individual measurement data appear unimodal, the distribution of gamma-ray dose-rates when averaged over relatively small areas, which probably better represents the underlying distribution with inter-house variation reduced, appears bimodal. The dose-rate distributions predicted by three empirical and geostatistical models are also bimodal and compatible with the distributions of the areally averaged dose-rates. The distribution of indoor gamma-ray dose-rates in the UK is compared with those in other countries, which also tend to appear bimodal (or possibly multimodal). The variation of indoor gamma-ray dose-rates with geology, socio-economic status of the area, building type, and period of construction are explored. The factors affecting indoor dose-rates from background gamma radiation are complex and frequently intertwined, but geology, period of construction, and socio-economic status are influential; the first is potentially most influential, perhaps, because it can be used as a general proxy for local building materials. Various statistical models are tested for predicting indoor gamma-ray dose-rates at unmeasured locations. Significant improvements over previous modelling are reported. The dose-rate estimates generated by these models reflect the imputed underlying distribution of dose-rates and provide acceptable predictions at geographical locations without measurements.
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Affiliation(s)
- G M Kendall
- Cancer Epidemiology Unit, NDPH, University of Oxford, Richard Doll Building, Old Road Campus, Headington, Oxford, OX3 7LF, UK.
| | - P Chernyavskiy
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, DHHS, NIH, Bethesda, MD, 20892-9778, USA
- Department of Mathematics and Statistics, Ross Hall 331, University of Wyoming, Laramie, WY, 82071-3036, USA
| | - J D Appleton
- British Geological Survey, Kingsley Dunham Centre, Nicker Hill, Keyworth, Nottingham, NG12 5GG, UK
| | - J C H Miles
- , Nobles Close, Grove, Oxfordshire, OX12 0NR, UK
| | - R Wakeford
- Centre for Occupational and Environmental Health, Institute of Population Health, The University of Manchester, Ellen Wilkinson Building, Oxford Road, Manchester, M13 9PL, UK
| | - M Athanson
- Bodleian Library, University of Oxford, Broad Street, Oxford, OX1 3BG, UK
| | - T J Vincent
- Childhood Cancer Research Group, University of Oxford, New Richards Building, Old Road, Oxford, UK
| | - N P McColl
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot Oxon, OX11 0RQ, UK
| | - M P Little
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, DHHS, NIH, Bethesda, MD, 20892-9778, USA
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