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Villeneuve PJ, Morrison HI, Lane R. Updated Analysis of Radon Exposure and Lung Cancer Mortality in the Cohort of Newfoundland Fluorspar Miners (1950-2016). Radiat Res 2024; 202:59-69. [PMID: 38649728 DOI: 10.1667/rade-23-00114.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 04/09/2024] [Indexed: 04/25/2024]
Abstract
The commercial mining of fluorspar in St. Lawrence Newfoundland began in 1933. Miners who worked underground were exposed to high levels of radon progeny, especially before ventilation was introduced into the mines in 1960. The mean cumulative radon exposure for underground miners in this cohort was 380.9 working level months (WLM). A series of studies of this cohort have characterized the increased risks of lung cancer mortality due to radon. We have extended the follow-up of this cohort an additional 15 years to provide additional insights on the risks of low levels of radon exposure, and the modifying effects of time since exposure, age at first exposure, attained age, duration of exposure, and cigarette smoking. The cohort consisted of 1,735 underground and 315 male surface miners who, combined, accrued 81,650 person-years of follow-up. The mortality experience of the cohort was determined from 1950-2016 through record linkage to Canadian national death data. Individual-level estimates of exposure to radon progeny, in WLMs, were determined for each year of employment. We compared the mortality experience of the underground miners to Newfoundland men using the standardized mortality ratio (SMR). Poisson regression models were fit to estimate excess relative risks (ERR) per 100 WLM. There were 236 lung cancer deaths identified, and of these, 221 occurred among underground workers. The SMR for lung cancer among underground miners compared to Newfoundland men was 2.67 (95% CI: 2.33, 3.04). The ERR per 100 WLM for lung cancer mortality, assuming a 5-year exposure lag, was 0.41 (95% CI: 0.23, 0.59). Attained age and time since exposure were important modifiers to the radon-lung cancer relationship. The joint relationship between smoking and radon on lung cancer risk was sub-additive, however, the smoking data were limited and available for only half of the cohort.
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Affiliation(s)
| | | | - Rachel Lane
- Canadian Nuclear Safety Commission, Ottawa, Canada
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Peters CE, Quinn EK, Rodriguez-Villamizar LA, MacDonald H, Villeneuve PJ. Exposure to low-dose radiation in occupational settings and ischaemic heart disease: a systematic review and meta-analysis. Occup Environ Med 2023; 80:706-714. [PMID: 37857488 DOI: 10.1136/oemed-2023-108865] [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: 02/08/2023] [Accepted: 09/30/2023] [Indexed: 10/21/2023]
Abstract
Ionising radiation is a human carcinogen, but the evidence is less clear that exposure to low-dose ionising radiation (LDIR) increases the risk of adverse cardiovascular outcomes. We synthesised the literature of chronic occupational exposure to LDIR and cardiovascular disease, particularly for ischaemic heart disease (IHD).The literature search was conducted using three databases including studies published between 1990 and 2022. A quality assessment of the studies was completed using the Office of Health and Assessment and Translation Risk of Bias Rating Tool. We conducted meta-analyses for IHD mortality using random effects models using measures of excess relative risk per sievert (ERR/Sv) obtained from internal cohort comparisons, as well as with standardised mortality ratios (SMRs) from external cohort comparisons.We identified 2189 articles, and of these, 26 provided data on IHD and were retained. Most studies were classified as having a 'moderate' level of risk of bias. Fourteen and 10 studies reporting external radiation doses were included in meta-analyses using SMR and ERR/Sv, respectively. The meta-summary SMR was 0.81 (95% CI 0.74 to 0.89) with evidence of reduced risk but high heterogeneity across studies. For internal cohort measures, the summary ERR/Sv for a lagged exposure of 10 years was 0.10 (95% CI 0.01 to 0.20) with low heterogeneity. The subgroup analysis by lagged exposure time showed the strongest association were for the 15 and 20 years lag.Our findings suggest that occupational exposure to LDIR increases the risk IHD mortality and highlight the relevance of internal cohort comparisons.
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Affiliation(s)
- Cheryl E Peters
- School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
- Population and Public Health, British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada
- Prevention, Screening and Hereditary Cancer, British Columbia Cancer, Vancouver, British Columbia, Canada
| | - Emma Kathleen Quinn
- School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Laura Andrea Rodriguez-Villamizar
- Department of Public Health, School of Medicine, Universidad Industrial de Santander, Bucaramanga, Santander, Colombia
- Deparment of Neurosciences, Carleton University, Ottawa, Ontario, Canada
| | | | - Paul J Villeneuve
- Deparment of Neurosciences, Carleton University, Ottawa, Ontario, Canada
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Circulatory system disease mortality and occupational exposure to radon progeny in the cohort of Newfoundland Fluorspar Miners between 1950 and 2016. Int Arch Occup Environ Health 2023; 96:411-418. [PMID: 36319769 PMCID: PMC9968242 DOI: 10.1007/s00420-022-01932-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Exposure to ionizing radiation may increase the risk of circulatory diseases, including heart disease. A limited number of cohort studies of underground miners have investigated these associations. We previously reported a positive but non-statistically significant association between radon progeny and heart disease in a cohort of Newfoundland fluorspar miners. In this study, we report updated findings that incorporate 15 additional years of follow-up. METHODS The cohort included 2050 miners who worked in the fluorspar mines from 1933 to 1978. Statistics Canada linked the personal identifying data of the miners to Canadian mortality data to identify deaths from 1950 to 2016. We used previously derived individual-level estimates of annual radon progeny exposure in working-level months. Cumulative exposure was categorized into quantiles. We estimated relative risks and their 95% confidence intervals using Poisson regression for deaths from circulatory, ischemic heart disease and acute myocardial infarction. Relative risks were adjusted for attained age, calendar year, and the average number of cigarettes smoked daily. RESULTS Relative to the Newfoundland male population, the standardized mortality ratio for circulatory disease in this cohort was 0.82 (95% CI 0.74-0.91). Those in the highest quantile of cumulative radon progeny exposure had a relative risk of circulatory disease mortality of 1.03 (95% CI 0.76-1.40) compared to those in the lowest quantile. The corresponding estimates for ischemic disease and acute myocardial infarction were 0.99 (95% CI 0.66-1.48), and 1.39 (95% CI 0.84-2.30), respectively. CONCLUSIONS Our findings do not support the hypothesis that occupational exposure to radon progeny increases the risk of circulatory disease.
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Richardson DB, Rage E, Demers PA, Do MT, Fenske N, Deffner V, Kreuzer M, Samet J, Bertke SJ, Kelly-Reif K, Schubauer-Berigan MK, Tomasek L, Zablotska LB, Wiggins C, Laurier D. Lung Cancer and Radon: Pooled Analysis of Uranium Miners Hired in 1960 or Later. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:57010. [PMID: 35604341 PMCID: PMC9126132 DOI: 10.1289/ehp10669] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/28/2022] [Accepted: 05/03/2022] [Indexed: 05/21/2023]
Abstract
BACKGROUND Despite reductions in exposure for workers and the general public, radon remains a leading cause of lung cancer. Prior studies of underground miners depended heavily upon information on deaths among miners employed in the early years of mine operations when exposures were high and tended to be poorly estimated. OBJECTIVES To strengthen the basis for radiation protection, we report on the follow-up of workers employed in the later periods of mine operations for whom we have more accurate exposure information and for whom exposures tended to be accrued at intensities that are more comparable to contemporary settings. METHODS We conducted a pooled analysis of cohort studies of lung cancer mortality among 57,873 male uranium miners in Canada, Czech Republic, France, Germany, and the United States, who were first employed in 1960 or later (thereby excluding miners employed during the periods of highest exposure and focusing on miners who tend to have higher quality assessments of radon progeny exposures). We derived estimates of excess relative rate per 100 working level months (ERR/100 WLM) for mortality from lung cancer. RESULTS The analysis included 1.9 million person-years of observation and 1,217 deaths due to lung cancer. The relative rate of lung cancer increased in a linear fashion with cumulative exposure to radon progeny (ERR/100 WLM = 1.33 ; 95% CI: 0.89, 1.88). The association was modified by attained age, age at exposure, and annual exposure rate; for attained ages < 55 y , the ERR/100 WLM was 8.38 (95% CI: 3.30, 18.99) among miners who were exposed at ≥ 35 years of age and at annual exposure rates of < 0.5 working levels. This association decreased with older attained ages, younger ages at exposure, and higher exposure rates. DISCUSSION Estimates of association between radon progeny exposure and lung cancer mortality among relatively contemporary miners are coherent with estimates used to inform current protection guidelines. https://doi.org/10.1289/EHP10669.
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Affiliation(s)
| | - Estelle Rage
- Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | | | - Minh T. Do
- Occupational Cancer Research Centre, Toronto, Canada
| | - Nora Fenske
- Federal Office for Radiation Protection, Munich (Neuherberg), Germany
| | - Veronika Deffner
- Federal Office for Radiation Protection, Munich (Neuherberg), Germany
| | - Michaela Kreuzer
- Federal Office for Radiation Protection, Munich (Neuherberg), Germany
| | | | - Stephen J. Bertke
- National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
| | - Kaitlin Kelly-Reif
- National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
| | - Mary K. Schubauer-Berigan
- National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
- International Agency for Research on Cancer, Lyon, France
| | | | | | - Charles Wiggins
- University of New Mexico, Albuquerque, New Mexico, USA
- New Mexico Tumor Registry, Albuquerque, New Mexico, USA
| | - Dominique Laurier
- Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
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Marsh JW, Tomášek L, Laurier D, Harrison JD. EFFECTIVE DOSE COEFFICIENTS FOR RADON AND PROGENY: A REVIEW OF ICRP AND UNSCEAR VALUES. RADIATION PROTECTION DOSIMETRY 2021; 195:1-20. [PMID: 34278430 DOI: 10.1093/rpd/ncab106] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/19/2021] [Accepted: 06/12/2021] [Indexed: 05/27/2023]
Abstract
The International Commission on Radiological Protection (ICRP) publishes guidance on protection against radon exposure in homes and workplaces. ICRP Publication 137 recommends a dose coefficient of 3 mSv per mJ h m-3 (~10 mSv WLM-1) to be used in most circumstances of radon exposure, for workers in buildings and in underground mines. Recently, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reviewed radon epidemiology and dosimetry and concluded that its established dose coefficient of 1.6 mSv per mJ h m-3 (5.7 mSv WLM-1) should be retained for use in its comparisons of radiation exposures from different sources in a population. This paper explains and compares the reviews of the scientific evidence from UNSCEAR and ICRP. It is shown that the UNSCEAR and ICRP reviews are consistent and support the use of the ICRP reference dose coefficients for radiation protection purposes. It is concluded that the ICRP dose coefficient should be used to calculate doses to workers.
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Affiliation(s)
- James W Marsh
- Public Health England. Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon. OX11 0RQ, UK
| | | | - Dominique Laurier
- Institut de Radioprotection et de Sûreté Nucléaire, 92262 Fontenay-aux-Roses Cedex, France
| | - John D Harrison
- Public Health England. Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon. OX11 0RQ, UK
- Oxford Brookes University, Faculty of Health and Life Sciences, Oxford OX3 0BP, UK
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Tomasek L. LUNG CANCER LIFETIME RISKS IN COHORT STUDIES OF URANIUM MINERS. RADIATION PROTECTION DOSIMETRY 2020; 191:171-175. [PMID: 33130900 DOI: 10.1093/rpd/ncaa143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
The article summarizes the most recent results from the cohorts of uranium miners, particularly the risks at low exposures and the risk models with modifying effects of exposure rate, age and time since exposure, which are used for the calculation of lifetime risks (LRs). The excess relative risks per unit exposure (ERR/WLM) arising from low exposures were found up to 10 times higher than the crude risk coefficients. For studies that reported models with modifying effect of age, time since exposure and exposure rate, LRs were calculated using the BEIR VI projection. These LRs were also calculated for a model with effect modification on the annual exposure rate. The results were prepared for the UNSCEAR report on 'Lung cancer from exposure to radon.'(1).
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Affiliation(s)
- Ladislav Tomasek
- Dept of Research & Development, National Radiation Protection Institute, Prague CZ14000, Czech Republic
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Rage E, Richardson DB, Demers PA, Do M, Fenske N, Kreuzer M, Samet J, Wiggins C, Schubauer-Berigan MK, Kelly-Reif K, Tomasek L, Zablotska LB, Laurier D. PUMA - pooled uranium miners analysis: cohort profile. Occup Environ Med 2020; 77:194-200. [PMID: 32005674 PMCID: PMC8663280 DOI: 10.1136/oemed-2019-105981] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 12/02/2019] [Accepted: 12/21/2019] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Epidemiological studies of underground miners have provided clear evidence that inhalation of radon decay products causes lung cancer. Moreover, these studies have served as a quantitative basis for estimation of radon-associated excess lung cancer risk. However, questions remain regarding the effects of exposure to the low levels of radon decay products typically encountered in contemporary occupational and environmental settings on the risk of lung cancer and other diseases, and on the modifiers of these associations. These issues are of central importance for estimation of risks associated with residential and occupational radon exposures. METHODS The Pooled Uranium Miner Analysis (PUMA) assembles information on cohorts of uranium miners in North America and Europe. Data available include individual annual estimates of exposure to radon decay products, demographic and employment history information on each worker and information on vital status, date of death and cause of death. Some, but not all, cohorts also have individual information on cigarette smoking, external gamma radiation exposure and non-radiological occupational exposures. RESULTS The PUMA study represents the largest study of uranium miners conducted to date, encompassing 124 507 miners, 4.51 million person-years at risk and 54 462 deaths, including 7825 deaths due to lung cancer. Planned research topics include analyses of associations between radon exposure and mortality due to lung cancer, cancers other than lung, non-malignant disease, modifiers of these associations and characterisation of overall relative mortality excesses and lifetime risks. CONCLUSION PUMA provides opportunities to evaluate new research questions and to conduct analyses to assess potential health risks associated with uranium mining that have greater statistical power than can be achieved with any single cohort.
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Affiliation(s)
- Estelle Rage
- Institute for Radiological Protection and Nuclear Safety (IRSN), PSE-SANTE, SESANE, Fontenay-aux-Roses, France
| | | | | | - Minh Do
- Cancer Care Ontario, Toronto, Ontario, Canada
| | - Nora Fenske
- Federal Office for Radiation Protection, Department of Radiation Protection and Health, Neuherberg, Germany
| | - Michaela Kreuzer
- Federal Office for Radiation Protection, Department of Radiation Protection and Health, Neuherberg, Germany
| | | | - Charles Wiggins
- University of New Mexico, Albuquerque, New Mexico, USA
- New Mexico Tumor Registry, Albuquerque, New Mexico, USA
| | - Mary K Schubauer-Berigan
- International Agency for Research on Cancer, Lyon, France
- National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
| | - Kaitlin Kelly-Reif
- National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
| | | | - Lydia B Zablotska
- University of California, San Francisco, San Francisco, California, USA
| | - Dominique Laurier
- Institute for Radiological Protection and Nuclear Safety (IRSN), PSE-SANTE, SESANE, Fontenay-aux-Roses, France
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Lane RSD, Tomášek L, Zablotska LB, Rage E, Momoli F, Little J. Low radon exposures and lung cancer risk: joint analysis of the Czech, French, and Beaverlodge cohorts of uranium miners. Int Arch Occup Environ Health 2019; 92:747-762. [PMID: 30737558 PMCID: PMC6556158 DOI: 10.1007/s00420-019-01411-w] [Citation(s) in RCA: 14] [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: 07/23/2018] [Accepted: 01/23/2019] [Indexed: 12/05/2022]
Abstract
It is well established that high radon exposures increase the risk of lung cancer mortality. The effects of low occupational exposures and the factors that confound and modify this risk are not clear and are needed to inform current radiation protection of miners. The risk of lung cancer mortality at low radon exposures (< 100 working-level months) was assessed in the joint cohort analysis of Czech, French, and Canadian uranium miners, employed in 1953 or later. Statistical analysis was based on linear Poisson regression modeling with grouped cohort survival data. Two sensitivity analyses were used to assess potential confounding from tobacco smoking. A statistically significant linear relationship between radon exposure and lung cancer mortality was found. The excess relative risk per working-level month was 0.022 (95% confidence intervals: 0.013-0.034), based on 408 lung cancer deaths and 394,236 person-years of risk. Time since exposure was a statistically significant modifier; risk decreased with increasing time since exposure. A tendency for a decrease in risk with increasing attained age was observed, but this was not statistically significant. Exposure rate was not found to be a modifier of the excess relative risk. The potential confounding effect of tobacco smoking was estimated to be small and did not substantially change the radon-lung cancer mortality risk estimates. This joint cohort analysis provides strong evidence for an increased risk of lung cancer mortality from low occupational radon exposures. The results suggest that radiation protection measures continue to be important among current uranium miners.
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Affiliation(s)
- Rachel S. D. Lane
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Room 101, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
- Directorate of Environmental and Radiation Protection and Assessment (DERPA), Canadian Nuclear Safety Commission (CNSC), 280 Slater Street, Station B, P.O. Box 1046, Ottawa, ON K1P 5S9 Canada
| | - Ladislav Tomášek
- National Radiation Protection Institute (SURO), Bartoskova 28, 140 00 Prague, Czech Republic
| | - Lydia B. Zablotska
- Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, 550 16th St, San Francisco, CA 94158 USA
| | - Estelle Rage
- Institute for Radiological Protection and Nuclear Safety, B.P. 17, 92262 Fontenay-aux-Roses Cedex, France
| | - Franco Momoli
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Room 101, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
- Centre for Practice-Changing Research (Room L1152), Ottawa Hospital Research Institute, Children’s Hospital of Eastern Ontario Research Institute, 401 Smyth Rd, Ottawa, ON K1H 8L1 Canada
| | - Julian Little
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Room 101, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
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Seo S, Ha WH, Kang JK, Lee D, Park S, Kwon TE, Jin YW. Health effects of exposure to radon: implications of the radon bed mattress incident in Korea. Epidemiol Health 2019; 41:e2019004. [PMID: 30754959 PMCID: PMC6446066 DOI: 10.4178/epih.e2019004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 02/12/2019] [Indexed: 12/12/2022] Open
Abstract
Radon is a naturally occurring radioactive material formed by the slow decay of uranium and thorium found in the earth's crust or construction materials. Internal exposure to radon accounts for about half of the natural background radiation dose to which humans are exposed annually. Radon is a carcinogen and is the second leading cause of lung cancer following smoking. An association between radon and lung cancer has been consistently reported in epidemiological studies on mine workers and the general population with indoor radon exposure. However, associations have not been clearly established between radon and other diseases, such as leukemia and thyroid cancer. Radiation doses are assessed by applying specific dose conversion coefficients according to the source (e.g., radon or thoron) and form of exposure (e.g., internal or external). However, regardless of the source or form of exposure, the effects of a given estimated dose on human health are identical, assuming that individuals have the same sensitivity to radiation. Recently, radiation exceeding the annual dose limit of the general population (1 mSv/yr) was detected in bed mattresses produced by D company due to the use of a monazite-based anion powder containing uranium and thorium. This has sparked concerns about the health hazards for mattress users caused by radiation exposure. In light of this event, this study presents scientific information about the assessment of radon and thoron exposure and its human implications for human health, which have emerged as a recent topic of interest and debate in society.
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Affiliation(s)
- Songwon Seo
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Wi-Ho Ha
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jin-Kyu Kang
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Dalnim Lee
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Soojin Park
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Tae-Eun Kwon
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Young Woo Jin
- National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
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Ramkissoon A, Navaranjan G, Berriault C, Villeneuve PJ, Demers PA, Do MT. Histopathologic Analysis of Lung Cancer Incidence Associated with Radon Exposure among Ontario Uranium Miners. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15112413. [PMID: 30384407 PMCID: PMC6267329 DOI: 10.3390/ijerph15112413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/20/2018] [Accepted: 10/26/2018] [Indexed: 01/08/2023]
Abstract
Although radon is a well-established contributor to lung cancer mortality among uranium miners, the effects of radon decay products on different histopathologies of lung carcinoma are not well established. Using a retrospective cohort design, this study aims to examine the risks of lung cancer by histological subtypes associated with exposure to radon decay products among the Ontario Uranium Miners cohort. Cases were stratified by histological groups, and associated risks were estimated for cumulative radon exposure after adjustment for attained age and calendar period. Between 1969 and 2005, 1274 incident cases of primary lung cancer were identified. Of these, 1256 diagnoses (99%) contained information on histology. Squamous cell carcinoma was most common (31%), followed by adenocarcinoma (20%), large cells (18%), small cell lung carcinoma (14%), and other or unspecified cell types (17%). Of the histological sub-groups, small cell lung carcinoma had the strongest association with cumulative radon exposure; compared to the reference group (<1 cumulative working level months (WLM)), the highest exposure category (>60 cumulative WLM) had a relative risk (RR) of 2.76 (95% CI: 1.67⁻4.57). Adenocarcinoma had the lowest risk and was not significantly associated with exposure to radon decay products (RR = 1.49, 95% CI: 0.96⁻2.31). An increasing, linear trend in relative risk was noted with increasing cumulative WLM across small cell, squamous cell, and large cell lung carcinomas (Ptrend < 0.05). Similarly, the excess relative risk (ERR) per WLM was highest for small cell lung carcinoma (ERR/WLM = 0.15, p < 0.01), followed by squamous cell carcinoma (ERR/WLM = 0.12, p < 0.01). Non-statistically significant excess risk was observed for adenocarcinoma (ERR/WLM = 0.004, p = 0.07). Our analysis of the Ontario Uranium Miners cohort data shows differences in the magnitude of the risks across four histological subtypes of lung carcinoma; the strongest association was noted for small cell lung carcinoma, followed by squamous cell, large cell, and lastly adenocarcinoma, which showed no significant associations with exposure to radon decay products.
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Affiliation(s)
- Avinash Ramkissoon
- Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, ON M5G 2L3, Canada.
| | - Garthika Navaranjan
- Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, ON M5G 2L3, Canada.
| | - Colin Berriault
- Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, ON M5G 2L3, Canada.
| | - Paul J Villeneuve
- Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, ON M5G 2L3, Canada.
- Department of Health Sciences, Carleton University, 1125 Colonel by Drive, Ottawa, ON K1S 5B6, Canada.
| | - Paul A Demers
- Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, ON M5G 2L3, Canada.
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, ON M5T 3M7, Canada.
| | - Minh T Do
- Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue, Toronto, ON M5G 2L3, Canada.
- Department of Health Sciences, Carleton University, 1125 Colonel by Drive, Ottawa, ON K1S 5B6, Canada.
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, ON M5T 3M7, Canada.
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Richardson DB, Cardis E, Daniels RD, Gillies M, Haylock R, Leuraud K, Laurier D, Moissonnier M, Schubauer-Berigan MK, Thierry-Chef I, Kesminiene A. Site-specific Solid Cancer Mortality After Exposure to Ionizing Radiation: A Cohort Study of Workers (INWORKS). Epidemiology 2018; 29:31-40. [PMID: 28991003 PMCID: PMC5875434 DOI: 10.1097/ede.0000000000000761] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND There is considerable scientific interest in associations between protracted low-dose exposure to ionizing radiation and the occurrence of specific types of cancer. METHODS Associations between ionizing radiation and site-specific solid cancer mortality were examined among 308,297 nuclear workers employed in France, the United Kingdom, and the United States. Workers were monitored for external radiation exposure and follow-up encompassed 8.2 million person-years. Radiation-mortality associations were estimated using a maximum-likelihood method and using a Markov chain Monte Carlo method, the latter used to fit a hierarchical regression model to stabilize estimates of association. RESULTS The analysis included 17,957 deaths attributable to solid cancer, the most common being lung, prostate, and colon cancer. Using a maximum-likelihood method to quantify associations between radiation dose- and site-specific cancer, we obtained positive point estimates for oral, esophagus, stomach, colon, rectum, pancreas, peritoneum, larynx, lung, pleura, bone and connective tissue, skin, ovary, testis, and thyroid cancer; in addition, we obtained negative point estimates for cancer of the liver and gallbladder, prostate, bladder, kidney, and brain. Most of these estimated coefficients exhibited substantial imprecision. Employing a hierarchical model for stabilization had little impact on the estimated associations for the most commonly observed outcomes, but for less frequent cancer types, the stabilized estimates tended to take less extreme values and have greater precision than estimates obtained without such stabilization. CONCLUSIONS The results provide further evidence regarding associations between low-dose radiation exposure and cancer.
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Niwa O, Barcellos-Hoff MH, Globus RK, Harrison JD, Hendry JH, Jacob P, Martin MT, Seed TM, Shay JW, Story MD, Suzuki K, Yamashita S. ICRP Publication 131: Stem Cell Biology with Respect to Carcinogenesis Aspects of Radiological Protection. Ann ICRP 2016; 44:7-357. [PMID: 26637346 DOI: 10.1177/0146645315595585] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This report provides a review of stem cells/progenitor cells and their responses to ionising radiation in relation to issues relevant to stochastic effects of radiation that form a major part of the International Commission on Radiological Protection's system of radiological protection. Current information on stem cell characteristics, maintenance and renewal, evolution with age, location in stem cell 'niches', and radiosensitivity to acute and protracted exposures is presented in a series of substantial reviews as annexes concerning haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. This foundation of knowledge of stem cells is used in the main text of the report to provide a biological insight into issues such as the linear-no-threshold (LNT) model, cancer risk among tissues, dose-rate effects, and changes in the risk of radiation carcinogenesis by age at exposure and attained age. Knowledge of the biology and associated radiation biology of stem cells and progenitor cells is more developed in tissues that renew fairly rapidly, such as haematopoietic tissue, intestinal mucosa, and epidermis, although all the tissues considered here possess stem cell populations. Important features of stem cell maintenance, renewal, and response are the microenvironmental signals operating in the niche residence, for which a well-defined spatial location has been identified in some tissues. The identity of the target cell for carcinogenesis continues to point to the more primitive stem cell population that is mostly quiescent, and hence able to accumulate the protracted sequence of mutations necessary to result in malignancy. In addition, there is some potential for daughter progenitor cells to be target cells in particular cases, such as in haematopoietic tissue and in skin. Several biological processes could contribute to protecting stem cells from mutation accumulation: (a) accurate DNA repair; (b) rapidly induced death of injured stem cells; (c) retention of the DNA parental template strand during divisions in some tissue systems, so that mutations are passed to the daughter differentiating cells and not retained in the parental cell; and (d) stem cell competition, whereby undamaged stem cells outcompete damaged stem cells for residence in the niche. DNA repair mainly occurs within a few days of irradiation, while stem cell competition requires weeks or many months depending on the tissue type. The aforementioned processes may contribute to the differences in carcinogenic radiation risk values between tissues, and may help to explain why a rapidly replicating tissue such as small intestine is less prone to such risk. The processes also provide a mechanistic insight relevant to the LNT model, and the relative and absolute risk models. The radiobiological knowledge also provides a scientific insight into discussions of the dose and dose-rate effectiveness factor currently used in radiological protection guidelines. In addition, the biological information contributes potential reasons for the age-dependent sensitivity to radiation carcinogenesis, including the effects of in-utero exposure.
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Mortality analyses in the updated French cohort of uranium miners (1946-2007). Int Arch Occup Environ Health 2014; 88:717-30. [PMID: 25410273 DOI: 10.1007/s00420-014-0998-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/10/2014] [Indexed: 12/27/2022]
Abstract
PURPOSE The objectives are to analyze mortality risks in the extended follow-up of the French uranium miners' cohort and to examine their potential relation to occupational exposure to ionizing radiation (IR). METHODS The total cohort includes 5,086 uranium miners employed in the CEA-COGEMA group and followed up from 1946 to 2007. Vital status, causes of death, and cumulative radon exposures were recorded. The post-55 subcohort includes 3,377 miners first employed after 1955, for whom long-lived radionuclides (LLR) and external gamma-ray exposure were also recorded. External mortality analyses were performed by computing standardized mortality ratios (SMR). Excess relative risks (ERRs) due to IR exposures were estimated from Poisson regression models. RESULTS The miners included in the total cohort were followed up for 35.4 years and exposed to 36.6 working level months (WLM) on average. There was no evidence of a difference in overall mortality between miners and the general French male population. Miners had a statistically significant excess mortality rate from lung cancer (SMR = 1.34 [95% CI 1.16-1.53]) and from kidney cancer (SMR = 1.60 [1.03-2.39]). Cumulative radon exposure was significantly associated with lung cancer risk (ERR/100 WLM = 0.71 [0.31-1.30]) and cerebrovascular risk (ERR/100 WLM = 0.41 [0.04-1.03]). In the post-55 subcohort, this excess mortality from lung cancer remained associated with exposure to radon, and also with exposure to LLR and external gamma rays. CONCLUSIONS The analyses in the extended follow-up strengthen the results previously observed among French uranium miners about their excess risk of mortality and its association with their occupational IR exposure.
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Abstract
Concerns have been expressed recently regarding the observed increased DNA damage from activities such as thinking and exercise. Such concerns have arisen from an incomplete accounting of the full effects of the increased oxidative damage. When the effects of the induced adaptive protective responses such as increased antioxidants and DNA repair enzymes are taken into consideration, there would be less endogenous DNA damage during the subsequent period of enhanced defenses, resulting in improved health from the thinking and exercise activities. Low dose radiation (LDR), which causes oxidative stress and increased DNA damage, upregulates adaptive protection systems that may decrease diseases in an analogous manner. Though there are ongoing debates regarding LDR's carcinogenicity, with two recent advisory committee reports coming to opposite conclusions, data published since the time of the reports have overwhelmingly ruled out its carcinogenicity, paving the way for consideration of its potential use for disease reduction. LDR adaptive protection is a promising approach to control neurodegenerative diseases, for which there are no methods of prevention or cure. Preparation of a compelling ethics case would pave the way for LDR clinical studies and progress in dealing with neurodegenerative diseases.
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Liu X, Fan Y, Jiang Y, Xiang J, Wang J, Sun Z, Ren G, Yao S, Chang R, Zhao Y, Qiao Y, Zhou Q. [A cohort study on risk factors of lung cancer in Yunnan tin miners]. ZHONGGUO FEI AI ZA ZHI = CHINESE JOURNAL OF LUNG CANCER 2013; 16:184-90. [PMID: 23601298 PMCID: PMC6000595 DOI: 10.3779/j.issn.1009-3419.2013.04.03] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
背景与目的 吸烟是肺癌的主要病因, 在矿工肺癌病因的研究中发现, 职业暴露因素也起重要作用。本研究旨在分析氡暴露、吸烟等危险因素对云锡矿工肺癌的影响, 为预防和控制肺癌高发提供科学依据。 方法 利用前瞻性队列研究方法, 对云锡矿工肺癌高危人群暴露因素对肺癌死亡的影响进行Cox多因素分析; 分析矿工肺癌危险与初始氡暴露年龄及氡暴露率的关系, 分析不同吸烟、氡暴露水平下肺癌死亡的危险, 并对吸烟和累积氡暴露量之间的交互作用进行分析。 结果 进入研究时的年龄、吸烟量、累积氡砷暴露、既往慢性支气管炎为云锡矿工肺癌的独立危险因素, 教育程度是矿工肺癌的保护性因素; 肺癌危险与氡暴露率间存在逆剂量率效应, 但与初始氡暴露年龄无明显关联; 吸烟和氡暴露对肺癌危险有显著的相加交互作用。 结论 云锡矿工肺癌高死亡率是多种因素共同作用的结果, 危险因素间的交互作用值得进一步深入研究。
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Affiliation(s)
- Xiaomei Liu
- Peking Union Medical College & Institute of Radiation Medicine, Chinese Academy of Medical Science, Tianjin 300192, China
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Zablotska LB, Lane RSD, Frost SE. Mortality (1950-1999) and cancer incidence (1969-1999) of workers in the Port Hope cohort study exposed to a unique combination of radium, uranium and γ-ray doses. BMJ Open 2013; 3:e002159. [PMID: 23449746 PMCID: PMC3586082 DOI: 10.1136/bmjopen-2012-002159] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/17/2013] [Accepted: 01/21/2013] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVES Uranium processing workers are exposed to uranium and radium compounds from the ore dust and to γ-ray radiation, but less to radon decay products (RDP), typical of the uranium miners. We examined the risks of these exposures in a cohort of workers from Port Hope radium and uranium refinery and processing plant. DESIGN A retrospective cohort study with carefully documented exposures, which allowed separation of those with primary exposures to radium and uranium. SETTINGS Port Hope, Ontario, Canada, uranium processors with no mining experience. PARTICIPANTS 3000 male and female workers first employed (1932-1980) and followed for mortality (1950-1999) and cancer incidence (1969-1999). OUTCOME MEASURES Cohort mortality and incidence were compared with the general Canadian population. Poisson regression was used to evaluate the association between cumulative RDP exposures and γ-ray doses and causes of death and cancers potentially related to radium and uranium processing. RESULTS Overall, workers had lower mortality and cancer incidence compared with the general Canadian population. In analyses restricted to men (n=2645), the person-year weighted mean cumulative RDP exposure was 15.9 working level months (WLM) and the mean cumulative whole-body γ-ray dose was 134.4 millisieverts. We observed small, non-statistically significant increases in radiation risks of mortality and incidence of lung cancer due to RDP exposures (excess relative risks/100 WLM=0.21, 95% CI <-0.45 to 1.59 and 0.77, 95% CI <-0.19 to 3.39, respectively), with similar risks for those exposed to radium and uranium. All other causes of death and cancer incidence were not significantly associated with RDP exposures or γ-ray doses or a combination of both. CONCLUSIONS In one of the largest cohort studies of workers exposed to radium, uranium and γ-ray doses, no significant radiation-associated risks were observed for any cancer site or cause of death. Continued follow-up and pooling with other cohorts of workers exposed to by-products of radium and uranium processing could provide valuable insight into occupational risks and suspected differences in risk with uranium miners.
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Affiliation(s)
- Lydia B Zablotska
- Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, California, USA
| | - Rachel S D Lane
- Radiation and Health Sciences Division, Directorate of Environmental and Radiation Protection and Assessment, Canadian Nuclear Safety Commission, Ottawa, Ontario, Canada
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Tirmarche M, Harrison J, Laurier D, Blanchardon E, Paquet F, Marsh J. Risk of lung cancer from radon exposure: contribution of recently published studies of uranium miners. Ann ICRP 2012; 41:368-77. [PMID: 23089036 DOI: 10.1016/j.icrp.2012.06.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The International Commission on Radiological Protection (ICRP) recently estimated the risk of lung cancer associated with radon exposure, and a statement was issued in ICRP Publication 115. This was based on recent epidemiological studies and the results from a joint analysis of cohorts of Czech, French, and German uranium miners, and indicated that the excess relative risk of lung cancer per unit of exposure should be expressed with consideration of chronic exposure over more than 10 years, by modelling time since median exposure, age attained or age at exposure, and taking in account, if possible, interaction between radon and tobacco. The lifetime excess absolute risk (LEAR) calculated from occupational exposure studies is close to 5 × 10(-4) per working level month (WLM) (14 × 10(-5) per hmJ/m(3)). LEAR values estimated using risk models derived from both miners and domestic exposure studies are in good agreement after accounting for factors such as sex, attained age, and exposure scenario. A sensitivity analysis highlighted the high dependence of background mortality rates on LEAR estimates. Using lung cancer rates among Euro-American males instead of the ICRP reference rates (males and females, and Euro-American and Asian populations), the estimated LEAR is close to 7 × 10(-4) per WLM (20 × 10(-5) per hm J/m(3)).
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Affiliation(s)
- M Tirmarche
- Institut de Radioprotection et de Sûreté Nucléaire, P.O. Box 17, 92262 Fontenay-aux-roses, Cedex, France.
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Eidemüller M, Jacob P, Lane RSD, Frost SE, Zablotska LB. Lung cancer mortality (1950-1999) among Eldorado uranium workers: a comparison of models of carcinogenesis and empirical excess risk models. PLoS One 2012; 7:e41431. [PMID: 22936975 PMCID: PMC3427320 DOI: 10.1371/journal.pone.0041431] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 06/25/2012] [Indexed: 11/19/2022] Open
Abstract
Lung cancer mortality after exposure to radon decay products (RDP) among 16,236 male Eldorado uranium workers was analyzed. Male workers from the Beaverlodge and Port Radium uranium mines and the Port Hope radium and uranium refinery and processing facility who were first employed between 1932 and 1980 were followed up from 1950 to 1999. A total of 618 lung cancer deaths were observed. The analysis compared the results of the biologically-based two-stage clonal expansion (TSCE) model to the empirical excess risk model. The spontaneous clonal expansion rate of pre-malignant cells was reduced at older ages under the assumptions of the TSCE model. Exposure to RDP was associated with increase in the clonal expansion rate during exposure but not afterwards. The increase was stronger for lower exposure rates. A radiation-induced bystander effect could be a possible explanation for such an exposure response. Results on excess risks were compared to a linear dose-response parametric excess risk model with attained age, time since exposure and dose rate as effect modifiers. In all models the excess relative risk decreased with increasing attained age, increasing time since exposure and increasing exposure rate. Large model uncertainties were found in particular for small exposure rates.
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Affiliation(s)
- Markus Eidemüller
- Helmholtz Zentrum München, Institute of Radiation Protection, Neuherberg, Germany.
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Abstract
Recent epidemiological studies of the association between lung cancer and exposure to radon and its decay products are reviewed. Particular emphasis is given to pooled case-control studies of residential exposures, and to cohorts of underground miners exposed to relatively low levels of radon. The residential and miner epidemiological studies provide consistent estimates of the risk of lung cancer, with significant associations observed at average annual concentrations of approximately 200 Bq/m³ and cumulative occupational levels of approximately 50 working level months (WLM), respectively. Based on recent results from combined analyses of epidemiological studies of miners, a lifetime excess absolute risk of 5 × 10⁻⁴ per WLM [14 × 10⁻⁵ per (mJh/m³)] should now be used as the nominal probability coefficient for radon- and radon-progeny-induced lung cancer, replacing the previous Publication 65 (ICRP, 1993) value of 2.8 × 10⁻⁴ per WLM [8 × 10⁻⁵ per (mJh/m³)]. Current knowledge of radon-associated risks for organs other than the lungs does not justify the selection of a detriment coefficient different from the fatality coefficient for radon-induced lung cancer. Publication 65 (ICRP, 2003) recommended that doses from radon and its progeny should be calculated using a dose conversion convention based on epidemiological data. It is now concluded that radon and its progeny should be treated in the same way as other radionuclides within the ICRP system of protection; that is, doses from radon and its progeny should be calculated using ICRP biokinetic and dosimetric models. ICRP will provide dose coefficients per unit exposure to radon and its progeny for different reference conditions of domestic and occupational exposure, with specified equilibrium factors and aerosol characteristics.
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Allodji RS, Leuraud K, Bernhard S, Henry S, Bénichou J, Laurier D. Assessment of uncertainty associated with measuring exposure to radon and decay products in the French uranium miners cohort. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2012; 32:85-100. [PMID: 22392893 DOI: 10.1088/0952-4746/32/1/85] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The reliability of exposure data directly affects the reliability of the risk estimates derived from epidemiological studies. Measurement uncertainty must be known and understood before it can be corrected. The literature on occupational exposure to radon ((222)Rn) and its decay products reveals only a few epidemiological studies in which uncertainty has been accounted for explicitly. This work examined the sources, nature, distribution and magnitude of uncertainty of the exposure of French uranium miners to radon ((222)Rn) and its decay products. We estimated the total size of uncertainty for this exposure with the root sum square (RSS) method, which may be an alternative when repeated measures are not available. As a result, we identified six main sources of uncertainty. The total size of the uncertainty decreased from about 47% in the period 1956-1974 to 10% after 1982, illustrating the improvement in the radiological monitoring system over time.
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Affiliation(s)
- Rodrigue S Allodji
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), DRPH, SRBE, Laboratoire d'Épidémiologie, BP17, 92262 Fontenay-aux-Roses Cedex, France.
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Abstract
The current radiation safety paradigm using the linear no-threshold (LNT) model is based on the premise that even the smallest amount of radiation may cause mutations increasing the risk of cancer. Autopsy studies have shown that the presence of cancer cells is not a decisive factor in the occurrence of clinical cancer. On the other hand, suppression of immune system more than doubles the cancer risk in organ transplant patients, indicating its key role in keeping occult cancers in check. Low dose radiation (LDR) elevates immune response, and so it may reduce rather than increase the risk of cancer. LNT model pays exclusive attention to DNA damage, which is not a decisive factor, and completely ignores immune system response, which is an important factor, and so is not scientifically justifiable. By not recognizing the importance of the immune system in cancer, and not exploring exercise intervention, the current paradigm may have missed an opportunity to reduce cancer deaths among atomic bomb survivors. Increased antioxidants from LDR may reduce aging-related non-cancer diseases since oxidative damage is implicated in these. A paradigm shift is warranted to reduce further casualties, reduce fear of LDR, and enable investigation of potential beneficial applications of LDR.
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Vacquier B, Rage E, Leuraud K, Caër-Lorho S, Houot J, Acker A, Laurier D. The influence of multiple types of occupational exposure to radon, gamma rays and long-lived radionuclides on mortality risk in the French "post-55" sub-cohort of uranium miners: 1956-1999. Radiat Res 2011; 176:796-806. [PMID: 21936607 DOI: 10.1667/rr2558.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The adverse health effects of radon on uranium miners, especially on their lungs, are well documented, but few studies have considered the effects of other radiation exposures. This study examined the mortality risks associated with exposure to radon, external γ rays and long-lived radionuclides (LLR) in the French "post-55" sub-cohort, which includes uranium miners first employed between 1956 and 1990 for whom all three types of exposure were assessed individually. Exposure-risk relationships were estimated with linear excess relative risk models and a 5-year lag time. The post-55 sub-cohort includes 3377 miners, contributing 89,405 person-years, followed up through the end of 1999 with a mean follow-up of 26.5 years. Mean cumulative exposure was 17.8 WLM for radon, 54.7 mSv for γ rays, and 1,632 Bq.m(-3).h for LLR. Among the 611 deaths observed, 66 were due to lung cancer. Annual individual exposures were significantly correlated. Increased mortality was observed for lung cancer (SMR = 1.30; 95% CI: 1.01, 1.65) and for brain and central nervous system (CNS) cancer (SMR = 2.00; 95% CI: 1.09, 3.35). Cumulative exposure to radon, γ rays and LLR was associated only with a significant risk of lung cancer. These new results could suggest an association between lung cancer and exposure to γ rays and LLR. They must nonetheless be interpreted with caution because of the correlation between the types of exposure. The calculation of organ doses received by each of these exposures would reduce the collinearity.
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Affiliation(s)
- Blandine Vacquier
- Institut de Radioprotection et de Sûreté Nucléaire, DRPH, SRBE, LEPID, Fontenay-aux-Roses, France
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Leuraud K, Schnelzer M, Tomasek L, Hunter N, Timarche M, Grosche B, Kreuzer M, Laurier D. Radon, smoking and lung cancer risk: results of a joint analysis of three European case-control studies among uranium miners. Radiat Res 2011; 176:375-87. [PMID: 21714633 DOI: 10.1667/rr2377.1] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A combined analysis of three case-control studies nested in three European uranium miner cohorts was performed to study the joint effects of radon exposure and smoking on lung cancer death risk. Occupational history and exposure data were available from the cohorts. Smoking information was reconstructed using self-administered questionnaires and occupational medical archives. Linear excess relative risk models adjusted for smoking were used to estimate the lung cancer risk associated with radon exposure. The study includes 1046 lung cancer cases and 2492 controls with detailed radon exposure data and smoking status. The ERR/WLM adjusted for smoking is equal to 0.008 (95% CI: 0.004-0.014). Time since exposure is shown to be a major modifier of the relationship between radon exposure and lung cancer risk. Fitting geometric mixture models yielded arguments in favor of a sub-multiplicative interaction between radon and smoking. This combined study is the largest case-control study to investigate the joint effects of radon and smoking on lung cancer risk among miners. The results confirm that the lung carcinogenic effect of radon persists even when smoking is adjusted for, with arguments in favor of a sub-multiplicative interaction between radon and smoking.
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Affiliation(s)
- Klervi Leuraud
- Institute for Radiological Protection and Nuclear Safety, B.P. 17, F-92262 Fontenay-aux-Roses Cedex, France
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Lane RSD, Frost SE, Howe GR, Zablotska LB. Mortality (1950-1999) and cancer incidence (1969-1999) in the cohort of Eldorado uranium workers. Radiat Res 2010; 174:773-85. [PMID: 21128801 DOI: 10.1667/rr2237.1] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This study assessed the relationship between radon decay product (RDP) exposure and mortality and cancer incidence in a cohort of 17,660 Eldorado uranium workers first employed in 1932-1980 and followed up through 1999. The analysis was based on substantially revised identifying information and dosimetry for workers from the Beaverlodge and Port Radium uranium mines and for the first time includes workers from a radium and uranium refinery and processing facility in Port Hope, Canada. Overall, male workers had lower mortality rates of all causes and all cancers and lower incidence rates of all cancers compared with the general Canadian male population, a likely healthy worker effect. Individual cancer rates were also reduced except for lung cancer mortality (SMR = 1.31, P < 0.001) and incidence (SIR = 1.23, P < 0.001). The excess relative risk per 100 WLM (ERR/100 WLM) of lung cancer mortality (N = 618, ERR/100 WLM = 0.55, 95% CI: 0.37, 0.78, P < 0.01) and incidence (N = 626, ERR/100 WLM = 0.55, 95% CI: 0.37, 0.81, P < 0.001) increased linearly with increasing RDP exposure. Adjustment for effect modification by time since exposure, exposure rate and age at risk resulted in comparable estimates of risk of lung cancer for all three uranium worksites. RDP exposures and γ-ray doses were not associated with any other cancer site or other cause of death. The risk estimates are in agreement with the results of the pooled analysis of 11 miner cohorts and more recent studies of uranium workers. The current analysis provides more precise risk estimates and compares the findings from the mortality study with the incidence study. Future follow-up of the cohort and joint analysis with other uranium miners' studies should shed more light on the effects of low RDP exposures as experienced by current workers as well as help to understand and address the health risks associated with residential radon.
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Affiliation(s)
- Rachel S D Lane
- Radiation and Health Sciences Division, Directorate of Environmental and Radiation Protection and Assessment, Canadian Nuclear Safety Commission, Ottawa, Ontario, Canada
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Kreuzer M, Grosche B, Schnelzer M, Tschense A, Dufey F, Walsh L. Radon and risk of death from cancer and cardiovascular diseases in the German uranium miners cohort study: follow-up 1946-2003. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2010; 49:177-85. [PMID: 19855993 DOI: 10.1007/s00411-009-0249-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 10/04/2009] [Indexed: 05/09/2023]
Abstract
Data from the German uranium miners cohort study were analyzed to investigate the radon-related risk of mortality from cancer and cardiovascular diseases. The Wismut cohort includes 58,987 men who were employed for at least 6 months from 1946 to 1989 at the former Wismut uranium mining company in Eastern Germany. By the end of 2003, a total of 3,016 lung cancer deaths, 3,355 deaths from extrapulmonary cancers, 5,141 deaths from heart diseases and 1,742 deaths from cerebrovascular diseases were observed. Although a number of studies have already been published on various endpoints in the Wismut cohort, the aim of the present analyses is to provide a direct comparison of the magnitude of radon-related risk for different cancer sites and cardiovascular diseases using the same data set, the same follow-up period and the same statistical methods. A specific focus on a group of cancers of the extrathoracic airways is also made here, due to the assumed high organ doses from absorbed radon progeny. Internal Poisson regression was used to estimate the excess relative risk (ERR) per unit of cumulative exposure to radon in working level months (WLM) and its 95% confidence limits (CI). There was a statistically significant increase in the risk of lung cancer with increasing radon exposure (ERR/WLM = 0.19%; 95% CI: 0.17%; 0.22%). A smaller, but also statistically significant excess was found for cancers of the extrathoracic airways and trachea (ERR/WLM = 0.062%; 95% CI: 0.002%; 0.121%). Most of the remaining nonrespiratory cancer sites showed a positive relationship with increasing radon exposure, which, however, did not reach statistical significance. No increase in risk was noted for coronary heart diseases (ERR/WLM = 0.0003%) and cerebrovascular diseases (ERR/WLM = 0.001%). The present data provide clear evidence of an increased radon-related risk of death from lung cancer, some evidence for an increased radon-related risk of death from cancers of the extrathoracic airways and some other extrapulmonary cancers, and no evidence for mortality from cardiovascular diseases. These findings are consistent with the results of other miner studies and dosimetric calculations for radon-related organ doses.
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Affiliation(s)
- Michaela Kreuzer
- Department of Radiation Protection and Health, Federal Office for Radiation Protection, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
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Walsh L, Tschense A, Schnelzer M, Dufey F, Grosche B, Kreuzer M. The influence of radon exposures on lung cancer mortality in German uranium miners, 1946-2003. Radiat Res 2010; 173:79-90. [PMID: 20041762 DOI: 10.1667/rr1803.1] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Extensive uranium extraction took place from 1946 until 1990 at the former Wismut mining company in East Germany. A total of 58,987 male former employees of this company form the largest single uranium miners cohort that has been followed up for causes of mortality occurring from the beginning of 1946 to the end of 2003. The purpose of this study was to investigate and evaluate different forms of models for the radon exposure-related lung cancer mortality risk based on 3,016 lung cancer deaths and 2 million person years. Other exposure covariables such as occupational exposure to external gamma radiation, long-lived radionuclides, arsenic, fine dust and silica dust are available. The standardized mortality ratio for lung cancer is 2.03 (95% CI: 1.96; 2.10). The simple cohort excess relative risk (ERR/WLM) for lung cancer is estimated as 0.0019 (95% CI: 0.0016; 0.0022). The BEIR VI model produced risks similar to those obtained with a selected mathematically continuous ERR model for lung cancer. The continuous model is linear in radon exposure with exponential effect modifiers that depend on the whole range of age at median exposure, time since median exposure, and radon exposure rate. In this model the central estimate of ERR/WLM is 0.0054 (95% CI: 0.0040; 0.0068) for an age at median exposure of 30 years, a time since median exposure of 20 years, and a mean exposure rate of 3 WL. The ERR decreases by 5% for each unit of exposure-rate increase. The ERR decreases by 28% with each decade increase in age at median exposure and also decreases by 51% with each decade increase in time since median exposure. The method of determination of radon exposure (i.e., whether the exposures were estimated or measured) did not play an important role in the determination of the ERR. The other exposure covariables were found to have only minor confounding influences on the ERR/WLM for the finally selected continuous model when included in an additive way.
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Affiliation(s)
- Linda Walsh
- Federal Office for Radiation Protection, Department Radiation Protection and Health, 85764 Oberschleissheim, Germany.
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Kreuzer M, Schnelzer M, Tschense A, Walsh L, Grosche B. Cohort profile: the German uranium miners cohort study (WISMUT cohort), 1946-2003. Int J Epidemiol 2009; 39:980-7. [PMID: 19494089 DOI: 10.1093/ije/dyp216] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michaela Kreuzer
- Federal Office for Radiation Protection, Department of Radiation Protection and Health, Neuherberg, Germany.
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Vearrier D, Curtis JA, Greenberg MI. Technologically enhanced naturally occurring radioactive materials. Clin Toxicol (Phila) 2009; 47:393-406. [DOI: 10.1080/15563650902997849] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
PURPOSE Radon is natural radioactive noble gas that can be found in soil, water, outdoor and indoor air. Exposure to radon accounts for more that 50% of the annual effective dose of natural radioactivity. The purpose of the current review is to summarize recent literature and evaluate the weight of evidence on the adverse health effects of radon. CONCLUSIONS Radon is an established human lung carcinogen based on human epidemiological data supported by experimental evidence of mutagenesis studies in cell culture and laboratory animals. Extrapolation from cohort studies on miners suggested that radon is the second leading cause of lung cancer death after tobacco smoke. The majority of studies on the relationship between radon and other types of cancers showed weak or no association. Low levels of radon can be found in drinking water; however, radon released during water usage adds small quantities to indoor radon concentration. Studies showed that the risk of stomach cancer and other gastrointestinal malignancies from radon in drinking water is small. Studies of the genetic and cytogenetic effects of indoor radon yielded equivocal results; while radon exposure in miners induces gene mutations and chromosomal aberrations. Numerous in vitro cytogenetic studies demonstrated that radon induces different types of genetic and cytogenetic damage that is likely to play a role in radon lung carcinogenesis.
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Affiliation(s)
- Mustafa Al-Zoughool
- McLaughlin Center for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.
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Vacquier B, Rogel A, Leuraud K, Caer S, Acker A, Laurier D. Radon-associated lung cancer risk among French uranium miners: modifying factors of the exposure-risk relationship. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2009; 48:1-9. [PMID: 18949479 DOI: 10.1007/s00411-008-0196-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 09/20/2008] [Indexed: 05/27/2023]
Abstract
Radon is classified as a known pulmonary carcinogen in humans. A better understanding of the effects of low exposure and time-dependent factors, modifying the lung cancer risk is of continued interest. We present analyses of the exposure-risk relationship in the French cohort of uranium miners updated until 1999 and including five additional years of follow-up. These new analyses provide a better opportunity to look at low radon exposures with longer follow-up intervals, and allow consideration of new modifying factors, such as physical activity, mine location and job type. The cohort includes 5,086 miners, and 159 lung cancer deaths have been observed among these over a follow-up of more than 30 years. The exposure-risk relationship was estimated using excess relative risk models, which allow investigation of several modifying factors such as period of exposure, time since exposure, age at exposure, duration of exposure, exposure rate, job type, mine type and physical activity. The analysis confirms the association between radon exposure and lung cancer risk (ERR per 100 WLM = 0.58, P < 0.01). Period of exposure and physical activity appear as major modifying factors. Higher risks are observed for hard physical activity works. The effect of hard physical activity persists when the period of exposure is taken into account (ERR per 100 WLM = 2.95, P < 0.01).
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Affiliation(s)
- Blandine Vacquier
- Institut de Radioprotection et de Sûreté Nucléaire, BP 17, 92262, Fontenay aux Roses, France.
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Sanders CL. PREVENTION OF CIGARETTE SMOKE INDUCED LUNG CANCER BY LOW LET IONIZING RADIATION. NUCLEAR ENGINEERING AND TECHNOLOGY 2008. [DOI: 10.5516/net.2008.40.7.539] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Kreuzer M, Walsh L, Schnelzer M, Tschense A, Grosche B. Radon and risk of extrapulmonary cancers: results of the German uranium miners' cohort study, 1960-2003. Br J Cancer 2008; 99:1946-53. [PMID: 19002172 PMCID: PMC2600695 DOI: 10.1038/sj.bjc.6604776] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 10/20/2008] [Accepted: 10/20/2008] [Indexed: 11/08/2022] Open
Abstract
Data from the German miners' cohort study were analysed to investigate whether radon in ambient air causes cancers other than lung cancer. The cohort includes 58,987 men who were employed for at least 6 months from 1946 to 1989 at the former Wismut uranium mining company in Eastern Germany. A total of 20,684 deaths were observed in the follow-up period from 1960 to 2003. The death rates for 24 individual cancer sites were compared with the age and calendar year-specific national death rates. Internal Poisson regression was used to estimate the excess relative risk (ERR) per unit of cumulative exposure to radon in working level months (WLM). The number of deaths observed (O) for extrapulmonary cancers combined was close to that expected (E) from national rates (n=3340, O/E=1.02; 95% confidence interval (CI): 0.98-1.05). Statistically significant increases in mortality were recorded for cancers of the stomach (O/E=1.15; 95% CI: 1.06-1.25) and liver (O/E=1.26; 95% CI: 1.07-1.48), whereas significant decreases were found for cancers of the tongue, mouth, salivary gland and pharynx combined (O/E=0.80; 95% CI: 0.65-0.97) and those of the bladder (O/E=0.82; 95% CI: 0.70-0.95). A statistically significant relationship with cumulative radon exposure was observed for all extrapulmonary cancers (ERR/WLM=0.014%; 95% CI: 0.006-0.023%). Most sites showed positive exposure-response relationships, but these were insignificant or became insignificant after adjustment for potential confounders such as arsenic or dust exposure. The present data provide some evidence of increased risk of extrapulmonary cancers associated with radon, but chance and confounding cannot be ruled out.
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Affiliation(s)
- M Kreuzer
- Federal Office for Radiation Protection, Department of Radiation Protection and Health, Neuherberg 85764, Germany.
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Rafique M, Jabeen S, Shahzad MI. General public's and physicians' perception of health risk associated with radon exposure in the state of Azad Jammu and Kashmir. Public Health Nurs 2008; 25:327-35. [PMID: 18666938 DOI: 10.1111/j.1525-1446.2008.00713.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To conduct a radon awareness survey to examine the level of awareness and risk perception of indoor radon exposure among the general public, medical students, and physicians of the state of Azad Jammu and Kashmir, given that long-term exposure to indoor radon increases lifetime risk of lung cancer and may pose a substantial threat to public health. DESIGN Cross-sectional survey. SAMPLE Households by telephone (500), interviews with menial laborers (200), questionnaires to shopkeepers and government employees (1,000), undergraduates (200), social science graduates (1,500), science graduates (1,500), medical students (325), and physicians (100). MEASURES Familiarity with radioactivity and the nature and health hazards of radiation and radon. ANALYSIS Significance of data trends was measured using the Kruskal-Wallis test. RESULTS About 30% people (excluding medical students and physicians) were aware of radon, and about 6% had knowledgeable awareness of radon. About 80% of the medical students and physicians had heard about radon and about 30.5% of them had knowledgeable awareness about radon and its hazards. CONCLUSION The study suggested a positive relationship of awareness of radon and its hazards with the educational level of people.
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Affiliation(s)
- Muhammad Rafique
- Department of Physics, University of Azad Jammu & Kashmir, Muzaffarbad 13100, Azad Kashmir, Pakistan.
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Villeneuve PJ, Lane RSD, Morrison HI. Coronary heart disease mortality and radon exposure in the Newfoundland fluorspar miners' cohort, 1950-2001. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2007; 46:291-6. [PMID: 17453229 DOI: 10.1007/s00411-007-0108-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2006] [Accepted: 03/24/2007] [Indexed: 05/15/2023]
Abstract
Kreuzer and coworkers recently reported no association between cumulative exposure to radiation and death from cardiovascular disease in a cohort of German uranium miners. Here, we report on the relationship between cumulative exposure to radon progeny and coronary heart disease among Newfoundland fluorspar miners. Previous analyses in this cohort found elevated death rates from coronary heart disease among those with higher cumulative radon exposure. However, this finding was based on a relatively small number of deaths and was not statistically significant. Since then, the follow-up of this cohort has been extended by 10 years until the end of 2001. Among the 2,070 miners in our study, 267 died from coronary heart disease. There was no trend evident between cumulative exposure to radon and the relative risk of death from coronary heart disease (P = 0.63). This finding was unchanged after adjusting for the lifetime smoking status that was available for approximately 54% of the cohort. Similarly, the cumulative radon exposure was found to be unrelated to deaths of the circulatory system, acute myocardial infarction, and cerebrovascular disease. These findings are consistent with those recently reported by Kreuzer and colleagues. We share their view that uncontrolled confounding for other coronary heart disease risk factors hinders the interpretation of the risk estimates.
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Affiliation(s)
- Paul J Villeneuve
- Biostatistics and Epidemiology Division, Health Canada, Ottawa, ON, Canada.
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