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Milder CM, Bellamy MB, Howard SC, Ellis ED, Golden AP, Cohen SS, Mumma MT, French B, Zablotska LB, Boice JD. Mortality follow-up of Fernald Feed Materials Production Center workers exposed to uranium from 1951 to 1985. Occup Environ Med 2024; 81:439-447. [PMID: 39147576 DOI: 10.1136/oemed-2023-109192] [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: 09/01/2023] [Accepted: 08/01/2024] [Indexed: 08/17/2024]
Abstract
OBJECTIVE This follow-up study of uranium processing workers at the Fernald Feed Materials Production Center examines the relationship between radiation exposure and cancer and non-cancer mortality among 6403 workers employed for at least 30 days between 1951 and 1985. METHODS We estimated cumulative, individual, annualised doses to 15 organs/tissues from external, internal and radon exposures. Vital status and cause of death were ascertained in 2017. The analysis employed standardised mortality ratios, Cox proportional hazards and Poisson regression models. Competing risk analysis was conducted for cardiovascular disease (CVD) mortality risk given several assumptions about risk independent of competing outcomes. Emphysema was examined to assess the potential for confounding by smoking. RESULTS Vital status was confirmed for 98.1% of workers, with 65.1% deceased. All-cause mortality was less than expected in salaried but not hourly workers when compared with the US population. A statistically significant dose response was observed between external (but not total or internal) lung dose and lung cancer mortality (HR at 100 mGy adjusted for internal dose=1.45; 95% CI=1.05 to 2.01). Significantly increased HRs at 100 mGy dose to heart were observed for CVD (1.27; 95% CI=1.07 to 1.50) and ischaemic heart disease (1.30; 95% CI=1.07 to 1.58). CVD risk remained elevated regardless of competing risk assumptions. Both external and internal radiation were associated with emphysema. CONCLUSIONS Lung cancer was associated with external dose, though positive dose responses for emphysema imply residual confounding by smoking. Novel use of competing risk analysis for CVD demonstrates leveraging retrospective data for future risk prediction.
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Affiliation(s)
- Cato M Milder
- Division of Epidemiology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA
| | - Michael B Bellamy
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, New York, USA
| | - Sara C Howard
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | - Elizabeth D Ellis
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | - Ashley P Golden
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | - Sarah S Cohen
- Social & Scientific Systems, a DLH Holdings Corporation, Durham, North Carolina, USA
| | - Michael T Mumma
- International Epidemiology Institute, Rockville, Maryland, USA
- International Epidemiology Field Station, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Benjamin French
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lydia B Zablotska
- Department of Epidemiology and Biostatistics, School of Medicine, University of California San Francisco, San Francisco, California, USA
| | - John D Boice
- Division of Epidemiology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- National Council on Radiation Protection and Measurements, Bethesda, Maryland, USA
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Dauer LT, Walsh L, Mumma MT, Cohen SS, Golden AP, Howard SC, Roemer GE, Boice JD. Moon, Mars and Minds: Evaluating Parkinson's disease mortality among U.S. radiation workers and veterans in the million person study of low-dose effects. Z Med Phys 2024; 34:100-110. [PMID: 37537100 PMCID: PMC10919963 DOI: 10.1016/j.zemedi.2023.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND Radiation is one of the most important stressors related to missions in space beyond Earth's orbit. Epidemiologic studies of exposed workers have reported elevated rates of Parkinson's disease. The importance of cognitive dysfunction related to low-dose rate radiation in humans is not defined. A meta-analysis was conducted of six cohorts in the Million Person Study (MPS) of low-dose health effects to learn whether there is consistent evidence that Parkinson's disease is associated with radiation dose to brain. MATERIALS AND METHODS The MPS evaluates all causes of death among U.S. radiation workers and veterans, including Parkinson's disease. Systematic and consistent methods are applied to study all categories of workers including medical radiation workers, industrial radiographers, nuclear power plant workers, atomic veterans, and Manhattan Projects workers at the Los Alamos National Laboratory and at Rocky Flats. Consistent methods for all cohorts are used to estimate organ-specific doses and to obtain vital status and cause of death. RESULTS The meta-analysis include 6 cohorts within the MPS, consisting of 517,608 workers and 17,219,001 person-years of observation. The mean dose to brain ranged from 6.9 to 47.6 mGy and the maximum dose from 0.76 to 2.7 Gy. Five of the 6 cohorts revealed positive associations with Parkinson's disease. The overall summary estimate from the meta-analysis was statistically significant based on 1573 deaths due to Parkinson's disease. The summary excess relative risk at 100 mGy was 0.17 (95% CI: 0.05; 0.29). CONCLUSIONS Parkinson's disease was positively associated with radiation in the MPS cohorts indicating the need for careful evaluation as to causality in other studies, delineation of possible mechanisms, and assessing possible implications for space travel as well as radiation protection guidance for terrestrial workers.
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Affiliation(s)
- Lawrence T Dauer
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Linda Walsh
- Department of Physics, University of Zürich, Zürich, Switzerland
| | - Michael T Mumma
- Vanderbilt University Medical Center's International Epidemiology Field Station, Rockville, MD, USA
| | | | - Ashley P Golden
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Sara C Howard
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Grace E Roemer
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA; Vanderbilt University School of Medicine, Nashville, TN, USA
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Milder CM, Howard SC, Ellis ED, Golden AP, Cohen SS, Mumma MT, Leggett RW, French B, Zablotska LB, Boice JD. Third mortality follow-up of the Mallinckrodt uranium processing workers, 1942-2019. Int J Radiat Biol 2024; 100:161-175. [PMID: 37819879 PMCID: PMC10843089 DOI: 10.1080/09553002.2023.2267640] [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: 01/27/2023] [Accepted: 09/28/2023] [Indexed: 10/13/2023]
Abstract
INTRODUCTION Mallinckrodt Chemical Works was a uranium processing facility during the Manhattan Project from 1942 to 1966. Thousands of workers were exposed to low-dose-rates of ionizing radiation from external and internal sources. This third follow-up of 2514 White male employees updates cancer and noncancer mortality potentially associated with radiation and silica dust. MATERIALS AND METHODS Individual, annualized organ doses were estimated from film badge records (n monitored = 2514), occupational chest x-rays (n = 2514), uranium urinalysis (n = 1868), radium intake through radon breath measurements (n = 487), and radon ambient measurements (n = 1356). Silica dust exposure from pitchblende processing was estimated (n = 1317). Vital status and cause of death determination through 2019 relied upon the National Death Index and Social Security Administration Epidemiological Vital Status Service. The analysis included standardized mortality ratios (SMRs), Cox proportional hazards, and Poisson regression models. RESULTS Vital status was confirmed for 99.4% of workers (84.0% deceased). For a dose weighting factor of 1 for intakes of uranium, radium, and radon decay products, the mean and median lung doses were 65.6 and 29.9 mGy, respectively. SMRs indicated a difference in health outcomes between salaried and hourly workers, and more brain cancer deaths than expected [SMR: 1.79; 95% confidence interval (CI): 1.14, 2.70]. No association was seen between radiation and lung cancer [hazard ratio (HR) at 100 mGy: 0.93; 95%CI: 0.78, 1.11]. The relationship between radiation and kidney cancer observed in the previous follow-up was maintained (HR at 100 mGy: 2.07; 95%CI: 1.12, 3.79). Cardiovascular disease (CVD) also increased significantly with heart dose (HR at 100 mGy: 1.11; 95%CI: 1.02, 1.21). Exposures to dust ≥23.6 mg/m3-year were associated with nonmalignant kidney disease (NMKD) (HR: 3.02; 95%CI: 1.12, 8.16) and kidney cancer combined with NMKD (HR: 2.46; 95%CI: 1.04, 5.81), though without evidence of a dose-response per 100 mg/m3-year. CONCLUSIONS This third follow-up of Mallinckrodt uranium processors reinforced the results of the previous studies. There was an excess of brain cancers compared with the US population, although no radiation dose-response was detected. The association between radiation and kidney cancer remained, though potentially due to few cases at higher doses. The association between levels of silica dust ≥23.6 mg/m3-year and NMKD also remained. No association was observed between radiation and lung cancer. A positive dose-response was observed between radiation and CVD; however, this association may be confounded by smoking, which was unmeasured. Future work will pool these data with other uranium processing worker cohorts within the Million Person Study.
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Affiliation(s)
- Cato M. Milder
- Division of Epidemiology, Vanderbilt University Medical Center, Nashville, TN, USA
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute
| | | | | | | | - Sarah S. Cohen
- EpidStrategies, a Division of ToxStrategies, Inc., Katy, TX
| | | | | | - Benjamin French
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lydia B. Zablotska
- Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, CA, USA
| | - John D. Boice
- Division of Epidemiology, Vanderbilt University Medical Center, Nashville, TN, USA
- National Council on Radiation Protection and Measurements (NCRP), Bethesda, MD, USA
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Boice JD, Cohen SS, Mumma MT, Golden AP, Howard SC, Girardi DJ, Ellis ED, Bellamy MB, Dauer LT, Eckerman KF, Leggett RW. Mortality among Tennessee Eastman Corporation (TEC) uranium processing workers, 1943-2019. Int J Radiat Biol 2023; 99:208-228. [PMID: 35758985 DOI: 10.1080/09553002.2022.2078003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND There are few occupational studies of women exposed to ionizing radiation. During World War II, the Tennessee Eastman Corporation (TEC) operated an electromagnetic field separation facility of 1152 calutrons to obtain enriched uranium (235U) used for the Hiroshima atomic bomb. Thousands of women were involved in these operations. MATERIALS AND METHODS A new study was conducted of 13,951 women and 12,699 men employed at TEC between 1943 and 1947 for at least 90 days. Comprehensive dose reconstruction techniques were used to estimate lung doses from the inhalation of uranium dust based on airborne measurements. Vital status through 2018/2019 was obtained from the National Death Index, Social Security Death Index, Tennessee death records and online public record databases. Analyses included standardized mortality ratios (SMRs) and Cox proportional hazards models. RESULTS Most workers were hourly (77.7%), white (95.6%), born before 1920 (58.3%), worked in dusty environments (57.0%), and had died (94.9%). Vital status was confirmed for 97.4% of the workers. Women were younger than men when first employed: mean ages 25.0 years and 33.0 years, respectively. The estimated mean absorbed dose to the lung was 32.7 mGy (max 1048 mGy) for women and 18.9 mGy (max 501 mGy) for men. The mean dose to thoracic lymph nodes (TLNs) was 127 mGy. Statistically significant SMRs were observed for lung cancer (SMR 1.25; 95% CI 1.19, 1.31; n = 1654), nonmalignant respiratory diseases (NMRDs) (1.23; 95% CI 1.19, 1.28; n = 2585), and cerebrovascular disease (CeVD) (1.13; 95% CI 1.08, 1.18; n = 1945). For lung cancer, the excess relative rate (ERR) at 100 mGy (95% CI) was 0.01 (-0.10, 0.12; n = 652) among women, and -0.15 (-0.38, 0.07; n = 1002) among men based on a preferred model for men with lung doses <300 mGy. NMRD and non-Hodgkin lymphoma were not associated with estimated absorbed dose to the lung or TLN. CONCLUSIONS There was little evidence that radiation increased the risk of lung cancer, suggesting that inhalation of uranium dust and the associated high-LET alpha particle exposure to lung tissue experienced over a few years is less effective in causing lung cancer than other types of exposures. There was no statistically significant difference in the lung cancer risk estimates between men and women. The elevation of certain causes of death such as CeVD is unexplained and will require additional scrutiny of workplace or lifestyle factors given that radiation is an unlikely contributor since only the lung and lymph nodes received appreciable dose.
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Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Department of Medicine, Division of Epidemiology, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | | | - Michael T Mumma
- International Epidemiology Institute, Rockville, MD, USA.,Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ashley P Golden
- ORISE Health Studies, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Sara C Howard
- ORISE Health Studies, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - David J Girardi
- ORISE Health Studies, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Elizabeth D Ellis
- ORISE Health Studies, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Michael B Bellamy
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lawrence T Dauer
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Boice JD, Cohen SS, Mumma MT, Howard SC, Yoder RC, Dauer LT. Mortality among medical radiation workers in the United States, 1965-2016. Int J Radiat Biol 2023; 99:183-207. [PMID: 34731066 DOI: 10.1080/09553002.2021.1967508] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Estimates of radiation risks following prolonged exposures at low doses and low-dose rates are uncertain. Medical radiation workers are a major component of the Million Person Study (MPS) of low-dose health effects. Annual personal dose equivalents, HP(10), for individual workers are available to facilitate dose-response analyses for lung cancer, leukemia, ischemic heart disease (IHD) and other causes of death. MATERIALS AND METHODS The Landauer, Inc. dosimetry database identified 109,019 medical and associated radiation workers first monitored 1965-1994. Vital status and cause of death were determined through 2016. Mean absorbed doses to red bone marrow (RBM), lung, heart, and other organs were estimated by adjusting the recorded HP(10) for each worker by scaling factors, accounting for exposure geometry, the energy of the incident photon radiation, sex of the worker and whether an apron was worn. There were 4 exposure scenarios: general radiology characterized by low-energy x-ray exposure with no lead apron use, interventional radiologists/cardiologists who wore aprons, nuclear medicine personnel and radiation oncologists exposed to high-energy photon radiation, and other workers. Standardized mortality ratio (SMR) analyses were performed. Cox proportional hazards models were used to estimate organ-specific radiation risks. RESULTS Overall, 11,433 deaths occurred (SMR 0.60; 95%CI 0.59,0.61), 126 from leukemia other than chronic lymphocytic leukemia (CLL), 850 from lung cancer, and 1654 from IHD. The mean duration of monitoring was 23.7 y. The excess relative rate (ERR) per 100 mGy was estimated as 0.10 (95% CI -0.34, 0.54) for leukemia other than CLL, 0.15 (0.02, 0.27) for lung cancer, and -0.10 (-0.27, 0.06) for IHD. The ERR for lung cancer was 0.16 (0.01, 0.32) among the 55,218 male workers and 0.09 (-0.19, 0.36) among the 53,801 female workers; a difference that was not statistically significant (p-value = 0.23). CONCLUSIONS Medical radiation workers were at increased risk for lung cancer that was higher among men than women, although this difference was not statistically significant. In contrast, the study of Japanese atomic bomb survivors exposed briefly to radiation in 1945 found females to be nearly 3 times the radiation risk of lung cancer compared with males on a relative scale. For medical workers, there were no statistically significant radiation associations with leukemia excluding CLL, IHD or other specific causes of death. Combining these data with other cohorts within the MPS, such as nuclear power plant workers and nuclear submariners, will enable more precise estimates of radiation risks at relatively low cumulative doses.
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Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN, USA
| | | | - Michael T Mumma
- International Epidemiology Institute, Rockville, MD, USA.,Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sara C Howard
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | | | - Lawrence T Dauer
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Boice JD, Quinn B, Al-Nabulsi I, Ansari A, Blake PK, Blattnig SR, Caffrey EA, Cohen SS, Golden AP, Held KD, Jokisch DW, Leggett RW, Mumma MT, Samuels C, Till JE, Tolmachev SY, Yoder RC, Zhou JY, Dauer LT. A million persons, a million dreams: a vision for a national center of radiation epidemiology and biology. Int J Radiat Biol 2021; 98:795-821. [PMID: 34669549 PMCID: PMC10594603 DOI: 10.1080/09553002.2021.1988183] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Epidemiologic studies of radiation-exposed populations form the basis for human safety standards. They also help shape public health policy and evidence-based health practices by identifying and quantifying health risks of exposure in defined populations. For more than a century, epidemiologists have studied the consequences of radiation exposures, yet the health effects of low levels delivered at a low-dose rate remain equivocal. MATERIALS AND METHODS The Million Person Study (MPS) of U.S. Radiation Workers and Veterans was designed to examine health effects following chronic exposures in contrast with brief exposures as experienced by the Japanese atomic bomb survivors. Radiation associations for rare cancers, intakes of radionuclides, and differences between men and women are being evaluated, as well as noncancers such as cardiovascular disease and conditions such as dementia and cognitive function. The first international symposium, held November 6, 2020, provided a broad overview of the MPS. Representatives from four U.S. government agencies addressed the importance of this research for their respective missions: U.S. Department of Energy (DOE), the Centers for Disease Control and Prevention (CDC), the U.S. Department of Defense (DOD), and the National Aeronautics and Space Administration (NASA). The major components of the MPS were discussed and recent findings summarized. The importance of radiation dosimetry, an essential feature of each MPS investigation, was emphasized. RESULTS The seven components of the MPS are DOE workers, nuclear weapons test participants, nuclear power plant workers, industrial radiographers, medical radiation workers, nuclear submariners, other U.S. Navy personnel, and radium dial painters. The MPS cohorts include tens of thousands of workers with elevated intakes of alpha particle emitters for which organ-specific doses are determined. Findings to date for chronic radiation exposure suggest that leukemia risk is lower than after acute exposure; lung cancer risk is much lower and there is little difference in risks between men and women; an increase in ischemic heart disease is yet to be seen; esophageal cancer is frequently elevated but not myelodysplastic syndrome; and Parkinson's disease may be associated with radiation exposure. CONCLUSIONS The MPS has provided provocative insights into the possible range of health effects following low-level chronic radiation exposure. When the 34 MPS cohorts are completed and combined, a powerful evaluation of radiation-effects will be possible. This final article in the MPS special issue summarizes the findings to date and the possibilities for the future. A National Center for Radiation Epidemiology and Biology is envisioned.
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Affiliation(s)
- John D. Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Brian Quinn
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Armin Ansari
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Steve R. Blattnig
- National Aeronautics and Space Administration Langley Research Center, Hampton, VA, USA
| | - Emily A. Caffrey
- Radian Scientific, LLC, Huntsville, AL, and Risk Assessment Corporation, Neeses, SC, USA
| | - Sarah S. Cohen
- EpidStrategies, a division of ToxStrategies, Inc, Cary, NC, USA
| | | | - Kathryn D. Held
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA
- Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA
| | - Derek W. Jokisch
- Francis Marion University, Florence, SC, USA
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - Michael T. Mumma
- Vanderbilt University School of Medicine, Nashville, TN, USA
- International Epidemiology Institute, Rockville, MD, USA
| | | | | | | | | | - Joey Y. Zhou
- United States Department of Energy, Gaithersburg, MD, USA
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Boice JD, Bouville A, Dauer LT, Golden AP, Wakeford R. Introduction to the special issue on the US Million Person Study of health effects from low-level exposure to radiation. Int J Radiat Biol 2021; 98:529-532. [PMID: 34612764 DOI: 10.1080/09553002.2021.1989906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Vanderbilt University Medical Center, Nashville, TN, USA
| | | | | | - Ashley P Golden
- ORISE Health Studies, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Richard Wakeford
- Centre for Occupational and Environmental Health, The University of Manchester, Manchester, UK
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Boice JD, Cohen SS, Mumma MT, Hagemeyer DA, Chen H, Golden AP, Yoder RC, Dauer LT. Mortality from Leukemia, Cancer and Heart Disease among U.S. Nuclear Power Plant Workers, 1957-2011. Int J Radiat Biol 2021; 98:657-678. [PMID: 34669562 DOI: 10.1080/09553002.2021.1967507] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The aim of the Million Person Study (MPS) of Low Dose Health Effects is to examine the level of radiation risk for chronic exposures received gradually over time and not acutely as was the case for the Japanese atomic bomb survivors. Nuclear power plant (NPP) workers comprise nearly 15 percent of the MPS. Leukemia, selected cancers, Parkinson's disease, ischemic heart disease (IHD) and other causes of death are evaluated. METHODS AND MATERIAL The U.S. Nuclear Regulatory Commission's Radiation Exposure Information and Reporting System (REIRS) and the Landauer, Inc. dosimetry databases identified 135,193 NPP workers first monitored 1957-1984. Annual personal dose equivalents [Hp(10)] were available for each worker. Radiation records from all places of employment were sought. Vital status was determined through 2011. Mean absorbed doses to red bone marrow (RBM), esophagus, lung, colon, brain and heart were estimated by adjusting the recorded Hp(10) for each worker by scaling factors, accounting for exposure geometry and energy of the incident gamma radiation. Standardized mortality ratios (SMR) were calculated. Radiation risks were estimated using Cox proportional hazards models. RESULTS Nearly 50% of workers were employed for more than 20 years. The mean duration of follow-up was 30.2 y. Overall, 29,076 total deaths occurred, 296 from leukemia other than chronic lymphocytic leukemia (CLL), 3,382 from lung cancer, 140 from Parkinson's disease and 5,410 from IHD. The mean dose to RBM was 37.9 mGy (maximum 1.0 Gy; percent >100 mGy was 9.2%), 43.2 mGy to lung, 43.7 mGy to colon, 33.2 mGy to brain, and 43.9 mGy to heart. The SMRs (95% CI) were 1.06 (0.94;1.19) for leukemia other than CLL, 1.10 (1.07;1.14) for lung cancer, 0.90 (0.76;1.06) for Parkinson's disease, and 0.80 (0.78; 0.82) for IHD. The excess relative risk (ERR) per 100 mGy for leukemia other than CLL was 0.15 (90% CI 0.001; 0.31). For all solid cancers the ERR per 100 mGy (95% CI) was 0.01 (-0.03; 0.05), for lung cancer -0.04 (-0.11; 0.02), for Parkinson's disease 0.24 (-0.02; 0.50), and for IHD -0.01 (-0.06; 0.04). CONCLUSION Prolonged exposure to radiation increased the risk of leukemia other than CLL among NPP workers. There was little evidence for a radiation-association for all solid cancers, lung cancer or ischemic heart disease. Increased precision will be forthcoming as the different cohorts within the MPS are combined, such as industrial radiographers and medical radiation workers who were assembled and evaluated in like manner.
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Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN, USA
| | | | - Michael T Mumma
- International Epidemiology Institute, Rockville, MD, USA.,Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - Heidi Chen
- Vanderbilt University Medical Center, Nashville, TN, USA
| | | | | | - Lawrence T Dauer
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
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Boice JD, Cohen SS, Mumma MT, Golden AP, Howard SC, Girardi DJ, Ellis ED, Bellamy MB, Dauer LT, Samuels C, Eckerman KF, Leggett RW. Mortality among workers at the Los Alamos National Laboratory, 1943-2017. Int J Radiat Biol 2021; 98:722-749. [PMID: 34047625 DOI: 10.1080/09553002.2021.1917784] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND During World War II (WWII), the Manhattan Engineering District established a secret laboratory in the mountains of northern New Mexico. The mission was to design, construct and test the first atomic weapon, nicknamed 'The Gadget' that was detonated at the TRINITY site in Alamogordo, NM. After WWII, nuclear weapons research continued, and the laboratory became the Los Alamos National Laboratory (LANL). MATERIALS AND METHODS The mortality experience of 26,328 workers first employed between 1943 and 1980 at LANL was determined through 2017. Included were 6157 contract workers employed by the ZIA Company. Organ dose estimates for each worker considered all sources of exposure, notably photons, neutrons, tritium, 238Pu and 239Pu. Vital status determination included searches within the National Death Index, Social Security Administration and New Mexico State Mortality Files. Standardized Mortality Ratios (SMR) and Cox regression models were used in the analyses. RESULTS Most workers (55%) were hired before 1960, 38% had a college degree, 25% were female, 81% white, 13% Hispanic and 60% had died. Vital status was complete, with only 0.1% lost to follow-up. The mean dose to the lung for the 17,053 workers monitored for radiation was 28.6 weighted-mGy (maximum 16.8 weighted-Gy) assuming a Dose Weighting Factor of 20 for alpha particle dose to lung. The Excess Relative Risk (ERR) at 100 weighted-mGy was 0.01 (95%CI -0.02, 0.03; n = 839) for lung cancer. The ERR at 100 mGy was -0.43 (95%CI -1.11, 0.24; n = 160) for leukemia other than chronic lymphocytic leukemia (CLL), -0.06 (95%CI -0.16, 0.04; n = 3043) for ischemic heart disease (IHD), and 0.29 (95%CI 0.02, 0.55; n = 106) for esophageal cancer. Among the 6499 workers with measurable intakes of plutonium, an increase in bone cancer (SMR 2.44; 95%CI 0.98, 5.03; n = 7) was related to dose. The SMR for berylliosis was significantly high, based on 4 deaths. SMRs for Hispanic workers were significantly high for cancers of the stomach and liver, cirrhosis of the liver, nonmalignant kidney disease and diabetes, but the excesses were not related to radiation dose. CONCLUSIONS There was little evidence that radiation increased the risk of lung cancer or leukemia. Esophageal cancer was associated with radiation, and plutonium intakes were linked to an increase of bone cancer. IHD was not associated with radiation dose. More precise evaluations will await the pooled analysis of workers with similar exposures such as at Rocky Flats, Savannah River and Hanford.
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Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | | | - Michael T Mumma
- International Epidemiology Institute, Rockville, MD, USA.,International Epidemiology Field Station, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ashley P Golden
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Sara C Howard
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - David J Girardi
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | | | - Michael B Bellamy
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lawrence T Dauer
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Golden AP, Milder CM, Ellis ED, Anderson JL, Boice JD, Bertke SJ, Zablotska LB. Cohort profile: four early uranium processing facilities in the US and Canada. Int J Radiat Biol 2021; 97:833-847. [PMID: 33970767 PMCID: PMC10201456 DOI: 10.1080/09553002.2021.1917786] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 12/22/2022]
Abstract
PURPOSE Pooling of individual-level data for workers involved in uranium refining and processing (excluding enrichment) may provide valuable insights into risks from occupational uranium and external ionizing radiation exposures. METHODS Data were pooled for workers from four uranium processing facilities (Fernald, Mallinckrodt and Middlesex from the U.S.; and Port Hope, Canada). Employment began as early as the 1930s and follow-up was as late as 2017. Workers were exposed to high concentrations of uranium, radium, and their decay products, as well as gamma radiation and ambient radon decay products. Exposure and outcome data were harmonized using similar definitions and dose reconstruction methods. Standardized mortality ratios (SMR) were estimated. RESULTS In total, 560 deaths from lung cancer, 503 non-malignant respiratory diseases, 67 renal diseases, 1,596 ischemic heart diseases, and 101 dementia and Alzheimer's disease (AD) were detected in the pooled cohort of over 12,400 workers (∼1,300 females). Mean cumulative doses were 45 millisievert for whole-body external ionizing radiation exposure and 172 milligray for lung dose from radon decay products. Only SMR for dementia and AD among males was statistically significant (SMR=1.29; 95% confidence interval: 1.04, 1.54). CONCLUSIONS This is the largest study to date to examine long-term health risks of uranium processing workers.
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Affiliation(s)
- Ashley P. Golden
- Oak Ridge Associated Universities, Health Studies Program, Oak Ridge, Tennessee
| | - Cato M. Milder
- Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, Tennessee, USA
| | - Elizabeth D. Ellis
- Oak Ridge Associated Universities, Health Studies Program, Oak Ridge, Tennessee
| | - Jeri L. Anderson
- National Institute for Occupational Safety and Health, Division of Field Studies and Engineering, Cincinnati, Ohio
| | - John D. Boice
- Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, Tennessee, USA
- National Council on Radiation Protection and Measurements (NCRP), Bethesda, Maryland
| | - Stephen J. Bertke
- National Institute for Occupational Safety and Health, Division of Field Studies and Engineering, Cincinnati, Ohio
| | - Lydia B. Zablotska
- Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, 550 16th Street, San Francisco, CA, U.S.A
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11
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Martinez NE, Jokisch DW, Dauer LT, Eckerman KF, Goans RE, Brockman JD, Tolmachev SY, Avtandilashvili M, Mumma MT, Boice JD, Leggett RW. Radium dial workers: back to the future. Int J Radiat Biol 2021; 98:750-768. [PMID: 33900890 PMCID: PMC10563809 DOI: 10.1080/09553002.2021.1917785] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 12/16/2022]
Abstract
PURPOSE This paper reviews the history of the radium dial workers in the United States, summarizes the scientific progress made since the last evaluation in the early 1990s, and discusses current progress in updating the epidemiologic cohort and applying new dosimetric models for radiation risk assessment. BACKGROUND The discoveries of radiation and radioactivity led quickly to medical and commercial applications at the turn of the 20th century, including the development of radioluminescent paint, made by combining radium with phosphorescent material and adhesive. Workers involved with the painting of dials and instruments included painters, handlers, ancillary workers, and chemists who fabricated the paint. Dial painters were primarily women and, prior to the mid to late 1920s, would use their lips to give the brush a fine point, resulting in high intakes of radium. The tragic experience of the dial painters had a significant impact on industrial safety standards, including protection measures taken during the Manhattan Project. The dial workers study has formed the basis for radiation protection standards for intakes of radionuclides by workers and the public. EPIDEMIOLOGIC APPROACH The mortality experience of 3,276 radium dial painters and handlers employed between 1913 and 1949 is being determined through 2019. The last epidemiologic follow-up was 30 years ago when most of these workers were still alive. Nearly 65% were born before 1920, 37.5% were teenagers when first hired, and nearly 50% were hired before 1930 when the habit of placing brushes in mouths essentially stopped. Comprehensive dose reconstruction techniques are being applied to estimate organ doses for each worker related to the intake of 226Ra, 228Ra, and associated photon exposures. Time dependent dose-response analyses will estimate lifetime risks for specific causes of death. DISCUSSION The study of radium dial workers is part of the Million Person Study of low-dose health effects that is designed to evaluate radiation risks among healthy American workers and veterans. Despite being one of the most important and influential radiation effects studies ever conducted, shifting programmatic responsibilities and declining funding led to the termination of the radium program of studies in the early 1990s. Renewed interest and opportunity have arisen. With scientific progress made in dosimetric methodology and models, the ability to perform a study over the entire life span, and the potential applicability to other scenarios such as medicine, environmental contamination and space exploration, the radium dial workers have once again come to the forefront.
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Affiliation(s)
- Nicole E. Martinez
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA
- Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Derek W. Jokisch
- Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Department of Physics and Engineering, Francis Marion University, Florence, SC, USA
| | - Lawrence T. Dauer
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Keith F. Eckerman
- Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - John D. Brockman
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - Sergey Y. Tolmachev
- United States Transuranium and Uranium Registries, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Richland, WA, USA
| | - Maia Avtandilashvili
- United States Transuranium and Uranium Registries, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Richland, WA, USA
| | - Michael T. Mumma
- International Epidemiology Institute, Rockville, MD, USA
- Department of Medicine, Division of Epidemiology, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | - John D. Boice
- Department of Medicine, Division of Epidemiology, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA
| | - Richard W. Leggett
- Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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12
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Boice JD, Cohen SS, Mumma MT, Chen H, Golden AP, Beck HL, Till JE. Mortality among U.S. military participants at eight aboveground nuclear weapons test series. Int J Radiat Biol 2020; 98:679-700. [PMID: 32602389 DOI: 10.1080/09553002.2020.1787543] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Approximately 235,000 military personnel participated at one of 230 U.S. atmospheric nuclear weapons tests from 1945 through 1962. At the Nevada Test Site (NTS), the atomic veterans participated in military maneuvers, observed nuclear weapons tests, or provided technical support. At the Pacific Proving Ground (PPG), they served aboard ships or were stationed on islands during or after nuclear weapons tests. MATERIAL AND METHODS Participants at seven test series, previously studied with high-quality dosimetry and personnel records, and the first test at TRINITY formed the cohort of 114,270 male military participants traced for vital status from 1945 through 2010. Dose reconstructions were based on Nuclear Test Personnel Review records, Department of Defense. Standardized mortality ratios (SMR) and Cox and Poisson regression models were used in the analysis. RESULTS Most atomic veterans were enlisted men, served in the Navy at the PPG, and were born before 1930. Vital status was determined for 96.8% of the veterans; 60% had died. Enlisted men had significantly high all-causes mortality SMR (1.06); officers had significantly low all-causes mortality SMR (0.71). The pattern of risk over time showed a diminution of the 'healthy soldier effect': the all-causes mortality SMR after 50 years of follow-up was 1.00. The healthy soldier effect for all cancers also diminished over time. The all-cancer SMR was significantly high after 50 years (SMR 1.10) primarily from smoking-related cancers, attributed in part to the availability of cigarettes in military rations. The highest SMR was for mesothelioma (SMR 1.56) which was correlated with asbestos exposure in naval ships. Prostate cancer was significantly high (SMR 1.13). Ischemic heart disease was significantly low (SMR 0.84). Estimated mean doses varied by organ were low; e.g., the mean red bone marrow dose was 6 mGy (maximum 108 mGy). Internal cohort dose-response analyses provided no evidence for increasing trends with radiation dose for leukemia (excluding chronic lymphocytic leukemia (CLL)) [ERR (95% CI) per 100 mGy -0.37 (-1.08, 0.33); n = 710], CLL, myelodysplastic syndrome, multiple myeloma, ischemic heart disease, or cancers of the lung, prostate, breast, and brain. CONCLUSION No statistically significant radiation associations were observed among 114,270 nuclear weapons test participants followed for up to 65 years. The 95% confidence limits were narrow and excluded mortality risks per unit dose that are two to four times higher than those reported in other investigations. Significantly elevated SMRs were seen for mesothelioma and asbestosis, attributed to asbestos exposure aboard ships.
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Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | - Sarah S Cohen
- EpidStrategies, a Division of ToxStrategies, Cary, NC, USA
| | | | - Heidi Chen
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN, USA
| | | | | | - John E Till
- Risk Assessment Corporation, Neeses, SC, USA
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13
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Mumma MT, Sirko JL, Boice JD, Blot WJ. Mesothelioma mortality within two radiation monitored occupational cohorts. Int J Radiat Biol 2019; 98:786-794. [PMID: 31290725 DOI: 10.1080/09553002.2019.1642540] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Purpose: The risk of mesothelioma, including cancers of the pleura and peritoneum, was examined within two large cohorts of workers monitored for exposure to ionizing radiation. Methods and materials: Mortality was assessed among 253,632 workers routinely monitored for external radiation, including 30,724 industrial radiographers (IR) at shipyards, 142,583 workers at nuclear power plants (NPP), and 83,441 IR who had not worked at an NPP or shipyard. Follow-up was from 1969 through 2011. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were computed; observed numbers of deaths from mesothelioma (including cancers of the pleura and peritoneum) and asbestosis were compared with numbers expected based on age-, sex-, and calendar year-specific national mortality rates. Job history and quantitative asbestos exposure data were unavailable, but work at a shipyard was taken as a surrogate for the likelihood of exposure. Cox proportional hazards models were used to estimate hazard ratios (HRs) for mesothelioma in relation to estimated cumulative radiation exposure to the lung. Results: The mean duration of follow-up was 25.3 years (max 42 years). The mean cumulative lung dose was 28.6 mGy (7.3% > 250 mGy). Nearly 20% of the workers had died by 2011. A total of 421 mesothelioma deaths were found (75% occurring after 1999) with increased SMRs among workers monitored in shipyards (SMR 9.97; 95% CI 8.50-11.63) and for NPP workers (SMR 5.55; 95% CI 4.88-6.29), but not for IR who had not worked in shipyards (SMR 1.15; 95% CI 0.53-2.19). Likewise, deaths from asbestosis (n = 189) were also increased for shipyard and NPP workers (SMR = 18.1 and 9.2, respectively), but not among workers who never worked at a shipyard or NPP (SMR = 0.70; n = 1). Radiation dose to the lung was not associated with a statistically meaningful dose-response trend for mesothelioma in the combined cohorts (HR at 100 mGy = 1.10; 95% CI 0.96-1.27; p = .18), nor was mesothelioma risk associated with radiation exposure among IR who had not worked in a shipyard and assumed minimally exposed to asbestos. Conclusions: An elevated rate of death from mesothelioma was observed in two radiation-exposed occupational groups with potential for asbestos exposure. The increased risk of death from asbestosis, combined with little evidence of a rising trend in mesothelioma mortality with increasing radiation exposure, suggests that the mesothelioma (and asbestosis) excess in these workers was due to asbestos exposure in shipyards and power plants and not to occupational low-dose radiation.
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Affiliation(s)
- Michael T Mumma
- a International Epidemiology Institute , Rockville , MD , USA.,b Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center , Nashville , TN , USA
| | | | - John D Boice
- c National Council on Radiation Protection and Measurements , Bethesda , MD , USA.,d Vanderbilt Epidemiology Center, Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center , Nashville , TN , USA
| | - William J Blot
- a International Epidemiology Institute , Rockville , MD , USA.,d Vanderbilt Epidemiology Center, Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center , Nashville , TN , USA.,e Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine , Nashville , TN , USA
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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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15
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Abstract
PURPOSE The study of low dose and low-dose rate exposure is of immeasurable value in understanding the possible range of health effects from prolonged exposures to radiation. The Million Person Study (MPS) of low-dose health effects was designed to evaluate radiation risks among healthy American workers and veterans who are more representative of today's populations than are the Japanese atomic bomb survivors exposed briefly to high-dose radiation in 1945. A million persons were needed for statistical reasons to evaluate low-dose and dose-rate effects, rare cancers, intakes of radioactive elements, and differences in risks between women and men. METHODS AND MATERIALS The MPS consists of five categories of workers and veterans exposed to radiation from 1939 to the present. The U.S. Department of Energy (DOE) Health and Mortality study began over 40 years ago and is the source of ∼360,000 workers. Over 25 years ago, the National Cancer Institute (NCI) collaborated with the U.S. Nuclear Regulatory Commission (NRC) to effectively create a cohort of nuclear power plant workers (∼150,000) and industrial radiographers (∼130,000). For over 30 years, the Department of Defense (DoD) collected data on aboveground nuclear weapons test participants (∼115,000). At the request of NCI in 1978, Landauer, Inc., (Glenwood, IL) saved their dosimetry databases which became the source of a cohort of ∼250,000 medical and other workers. RESULTS Overall, 29 individual cohorts comprise the MPS of which 21 have been or are under active study (∼810,000 persons). The remaining eight cohorts (∼190,000 persons) will be studied as resources become available. The MPS is a national effort with critical support from the NRC, DOE, National Aeronautics and Space Administration (NASA), DoD, NCI, the Centers for Disease Control and Prevention (CDC), the Environmental Protection Agency (EPA), Landauer, Inc., and national laboratories. CONCLUSIONS The MPS is designed to address the major unanswered question in radiation risk understanding: What is the level of health effects when exposure is gradual over time and not delivered briefly. The MPS will provide scientific understandings of prolonged exposure which will improve guidelines to protect workers and the public; improve compensation schemes for workers, veterans and the public; provide guidance for policy and decision makers; and provide evidence for or against the continued use of the linear nonthreshold dose-response model in radiation protection.
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Affiliation(s)
- John D Boice
- a National Council on Radiation Protection and Measurements , Bethesda , MD , USA.,b Department of Medicine, Division of Epidemiology , Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center , Nashville , TN , USA
| | | | - Michael T Mumma
- d International Epidemiology Institute , Rockville , MD , USA
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Haynes K. Mortality: The final outcome. Pharmacoepidemiol Drug Saf 2019; 28:570-571. [DOI: 10.1002/pds.4715] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 01/09/2023]
Affiliation(s)
- Kevin Haynes
- Department of Scientific AffairsHealthCore, Inc. Wilmington Delaware
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Boice JD, Ellis ED, Golden AP, Zablotska LB, Mumma MT, Cohen SS. Sex-specific lung cancer risk among radiation workers in the million-person study and patients TB-Fluoroscopy. Int J Radiat Biol 2019; 98:769-780. [PMID: 30614747 DOI: 10.1080/09553002.2018.1547441] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND The study of Japanese atomic bomb survivors, exposed briefly to radiation, finds the risk of radiation-induced lung cancer to be nearly three times greater for women than for men. Because protection standards for astronauts are based on individual lifetime risk projections, this sex-specific difference limits the time women can spend in space. Populations exposed to chronic or fractionated radiation were evaluated to learn whether similar differences exist when exposures occur gradually over years. METHODS AND MATERIALS Five occupational cohorts within the Million Person Study of Low-Dose Health Effects (MPS) and a Canadian Fluoroscopy Cohort Study (CFCS) of tuberculosis patients who underwent frequent chest fluoroscopic examinations are evaluated. Included are male and female workers at the Mound nuclear facility, nuclear power plants (NPP), and industrial radiographers (IR). Workers at the Mallinckrodt Chemical Works and military participants at aboveground nuclear weapons tests provide information on the risk among males. Cox proportional hazards and Poisson regression models were used to estimate sex-specific radiation risks for lung cancer and to compare any differences. RESULTS Overall, 15,065 lung cancers occurred among the 443,684 subjects studied: 50,111 women and 395,573 men. The mean cumulative dose to the lung was 166.3 mGy (range 6 to 1,055 mGy) with the highest among the TB-fluoroscopy patients (mean 1,055 mGy). Mean lung dose for women in the worker cohorts was generally 4 times lower than for men. Of the 12 estimates of radiation-related risk, only one, for male IRs, showed a significant elevation (ERR 0.09; 95% CI 0.02-0.16, at 100 mGy). In contrast, the dose response for male NPP workers was negative (ERR -0.05; 95% CI -0.10, 0.01, at 100 mGy). Combined, these two cohorts provided little evidence for a radiation effect among males (ERR 0.01; 95% CI -0.04, 0.06, at 100 mGy). There was no significant dose-response among females within any cohort. There was no difference in the sex-specific estimates of lung cancer risk. CONCLUSIONS There was little evidence that chronic or fractionated exposures increased the risk of lung cancer. There were no differences in the risks of lung cancer between men and women. However, the sex-specific analyses are limited because of small numbers of women and relatively low doses. A more definitive study is ongoing of medical radiation workers which include 85,000 women and 85,000 men (overall mean dose 82 mGy, max 1,140 mGy). Additional understanding will come from the ongoing follow-up of the CFCS.
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Affiliation(s)
- John D Boice
- a National Council on Radiation Protection and Measurements , Bethesda , MA , USA.,b Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center , Vanderbilt University School of Medicine , Nashville , TN , USA
| | - Elizabeth D Ellis
- c Center for Epidemiologic Research, Oak Ridge Associated Universities , Oak Ridge , TN , USA
| | - Ashley P Golden
- c Center for Epidemiologic Research, Oak Ridge Associated Universities , Oak Ridge , TN , USA
| | - Lydia B Zablotska
- d School of Medicine , University of California, San Francisco , San Francisco , CA , USA
| | - Michael T Mumma
- e International Epidemiology Institute , Rockville , MA , USA
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Golden AP, Cohen SS, Chen H, Ellis ED, Boice JD. Evaluation of statistical modeling approaches for epidemiologic studies of low-dose radiation health effects. Int J Radiat Biol 2019; 98:572-579. [DOI: 10.1080/09553002.2018.1554924] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
| | | | - Heidi Chen
- Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | | | - John D. Boice
- Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA
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Cohen SS, Mumma MT, Ellis ED, Boice JD. Validating the use of census data on education as a measure of socioeconomic status in an occupational cohort. Int J Radiat Biol 2019; 98:587-592. [DOI: 10.1080/09553002.2018.1549758] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
| | | | | | - John D. Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA
- Vanderbilt Epidemiology Center, Division of Epidemiology Department of Medicine, Vanderbilt-Ingram Cancer Center Vanderbilt University Medical Center, Nashville, TN, USA
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Ellis ED, Girardi D, Golden AP, Wallace PW, Phillips J, Cragle DL. Historical perspective on the department of energy mortality studies: focus on the collection and storage of individual worker data. Int J Radiat Biol 2019; 98:560-567. [DOI: 10.1080/09553002.2018.1547851] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Elizabeth D. Ellis
- Center for Epidemiologic Research, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - David Girardi
- Center for Epidemiologic Research, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Ashley P. Golden
- Center for Epidemiologic Research, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Phil W. Wallace
- Center for Epidemiologic Research, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Joyce Phillips
- Center for Epidemiologic Research, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Donna L. Cragle
- Center for Epidemiologic Research, Oak Ridge Associated Universities, Oak Ridge, TN, USA
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Till JE, Beck HL, Boice JD, Mohler HJ, Mumma MT, Aanenson JW, Grogan HA. Asbestos Exposure and Mesothelioma Mortality among Atomic Veterans. Int J Radiat Biol 2018; 98:781-785. [PMID: 30513236 DOI: 10.1080/09553002.2018.1551641] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND During the Cold War the United States (U.S.) conducted 230 above-ground atmospheric nuclear weapons tests between 1945 and 1962 at the Nevada Test Site and the Pacific Proving Grounds. These tests involved over 250,000 military personnel. Asbestos was used on the naval vessels for insulation in the boiler room, engine room, and other areas. This is the first quantitative assessment of asbestos-related mesothelioma, including cancers of the pleura and peritoneum, among military personnel who participated in above-ground nuclear weapons testing. METHODS Approximately 114,000 atomic veterans were selected for an epidemiological study because they were in one of eight series of weapons tests that were associated with somewhat higher personnel exposures than the other tests and because they have been previously studied. We were able to categorize specific jobs into potential for asbestos exposure based on a detailed database of the military activities of the atomic veterans, developed using historical records provided by the Defense Threat Reduction Agency. Standardized mortality ratios (SMR) were calculated by service, rank(officer/enlisted) and ratings (occupation code and work location aboard ship) after 65 years of follow-up… Results: Mesothelioma deaths were significantly increased overall (SMR 1.56; 95% CI 1.32-1.82; n= 153). This increase was seen only among those serving in the Pacific Proving Ground (SMR 1.97; 95% CI 1.65-2.34; n= 134), enlisted men (SMR 1.81; 95% CI 1.53-2.13; n= 145) and the 70,309 navy personnel (SMR 2.15; 95% CI 1.80-2.56; n= 130). No increased mortality rates were seen among the other services: army (SMR 0.45), air force (SMR 0.85) or marines (SMR 0.75). Job categories with the highest potential for asbestos exposure (machinist's mates, boiler technicians, water tender, pipe fitters, and fireman) had an of SMR 6.47. Job categories with lower potential (SMR =1.35) or no potential (SMR =1.28) for asbestos exposure had non-significantly elevated mesothelioma mortality. CONCLUSIONS Although jobs with high potential for exposure to asbestos products were held by only 20% of the enlisted naval population, sailors with these jobs (machinist's mate, pipe fitter, boiler technician, water tender and fireman) experienced 55% of mesothelioma deaths. The significantly higher mortality rate overall was explained by asbestos exposure among enlisted naval personnel in this low-dose radiation exposed cohort.
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Affiliation(s)
- John E Till
- a Risk Assessment Corporation , Neeses , SC 29107
| | | | - John D Boice
- a Risk Assessment Corporation , Neeses , SC 29107 ;,c National Council on Radiation Protection and Measurements , Bethesda , Maryland , USA ;,d Division of Epidemiology, Department of Medicine , Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center , Nashville , Tennessee , USA ; Vanderbilt Epidemiology Center, Division of Epidemiology, Department of Medicine , Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center , Nashville , TN , USA
| | | | - Michael T Mumma
- f International Epidemiology Institute , Rockville , MD , USA
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