International Journal of Radiation Biology, May 16, 2022
BACKGROUND Estimates of radiation risks following prolonged exposures at low doses and low-dose r... more 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, 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 1,654 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 =0.062). 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 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 industrial radiographers, will enable more precise estimates of radiation risks at relatively low cumulative doses.
Ionizing radiation is an established carcinogen, but its effects on non-malignant respiratory dis... more Ionizing radiation is an established carcinogen, but its effects on non-malignant respiratory disease (NMRD) are less clear. Cohorts exposed to multiple risk factors including radiation and toxic dusts conflate these relationships, and there is a need for clarity in previous findings. This systematic review was conducted to survey the body of existing evidence for radiation effects on NMRD in global nuclear worker cohorts. A PubMed search was conducted for studies with terms relating to radiation or uranium and noncancer respiratory outcomes. Papers were limited to the most recent report within a single cohort published between January 2000 and December 2020. Publication quality was assessed based upon UNSCEAR 2017 criteria. In total, 31 papers were reviewed. Studies included 29 retrospective cohorts, one prospective cohort, and one longitudinal cohort primarily comprising White men from the U.S., Canada and Western Europe. Ten studies contained subpopulations of uranium miners or millers. Papers reported standardized mortality ratio (SMR) analyses, regression analyses, or both. Neither SMR nor regression analyses consistently showed a relationship between radiation exposure and NMRD. A meta-analysis of excess relative risks (ERRs) for NMRD did not present evidence for a dose-response (overall ERR/Sv: 0.07; 95% CI: –0.07, 0.21), and results for more specific outcomes were inconsistent. Significantly elevated SMRs for NMRD overall were observed in two studies among the subpopulation of uranium miners and millers (combined n = 4229; SMR 1.42–1.43), indicating this association may be limited to mining and milling populations and may not extend to other nuclear workers. A quality review showed limited capacity of 17 out of 31 studies conducted to provide evidence for a causal relationship between radiation and NMRD; the higher-quality studies showed no consistent relationship. All elevated NMRD SMRs were among mining and milling cohorts, indicating different exposure profiles between mining and non-mining cohorts; future pooled cohorts should adjust for mining exposures or address mining cohorts separately.
BackgroundFor occupational medical screening programs focused on long‐term health surveillance, p... more BackgroundFor occupational medical screening programs focused on long‐term health surveillance, participant attrition is a significant barrier to success. We investigate demographic, medical history, and clinical data from National Supplemental Screening Program (NSSP) examinees for association with likelihood of return for a second exam (rescreening).MethodsA total of 15,733 individuals completed at least one NSSP exam before December 31, 2016; of those, 4832 also completed a second exam on or before December 31, 2019. Stepwise logistic regression models were used to identify variables associated with whether a participant was rescreened in the NSSP.ResultsIndividuals were less likely to return for rescreening if they had a history of any cancer; cardiovascular problems; diabetes or kidney disease; or if they used insulin. Age at time of first exam and job site category significantly influenced likelihood of return. Workers categorized as “guests” were more likely to return. Partic...
According to the US Bureau of Labor Statistics, the average age of retirement is 62. While many r... more According to the US Bureau of Labor Statistics, the average age of retirement is 62. While many retirees may have employer-provided or other access to healthcare, others have limited access to affordable care until full Medicare eligibility at 65. Regardless of access, retirees with toxic occupational exposures may not have providers with specialized knowledge of tests or diagnoses for exposure-related health conditions, especially those with long-latency. The National Supplemental Screening Program for U.S. Department of Energy Former Workers is described here as a nationwide program providing recurring (every 3 years) integrated health screenings designed to identify both occupational and non-occupational conditions in the context of exposure so that early identification can enable appropriate and timely diagnoses and treatments to improve health outcomes. Since September 2005, there has been 18,518 initial exams for former workers, of whom 5,461 returned for rescreening exams thr...
Abstract Background During World War II (WWII), the Manhattan Engineering District established a ... more 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.
Ecoregional assessments provide a regional scale, biodiversity-based context for implementing con... more Ecoregional assessments provide a regional scale, biodiversity-based context for implementing conservation efforts by identifying a portfolio of sites for conservation action with a goal of protecting representative biodiversity and ecologically significant populations. The intent of these assessments is to create a shared vision for agencies and other organizations at the regional, state, and local levels to form partnerships and to ensure efficient allocation of conservation resources. The Nature Conservancy of Canada recently completed an ecoregional assessment of British Columbia’s Central Interior, the main components of which are presented as articles in this special issue of the BC Journal of Ecosystems and Management. These components include terrestrial ecosystems and animals, and freshwater ecosystems and species. The assessment also incorporates some new and innovative approaches to considering conservation priorities along with climate change, ecosystem services, and wil...
The Central Interior Ecoregional Assessment brought together professionals from the Nature Conser... more The Central Interior Ecoregional Assessment brought together professionals from the Nature Conservancy of Canada, provincial government ministries, and academic researchers, to complete a conservation-based scientific analysis of the Central Interior region of British Columbia. Four principal products emerged from this effort: conservation portfolios, Marxan summed solutions, conservation value maps, and a comprehensive compilation of conservation data for the ecoregion. With the completion of this assessment, NCC has developed conservation plans for the vast majority of British Columbia.
We present a vulnerability-based approach for considering climate as a threat in regional conserv... more We present a vulnerability-based approach for considering climate as a threat in regional conservation planning. The protocol is based on best available understanding of the climate sensitivity of species and systems of concern, has little reliance on climate or ecological change scenarios, and can be executed rapidly. This approach has advantages of (1) not being tied to environmental scenarios with high uncertainty and (2) generating ‘no regrets’ strategies for planning for climate in the context of other threats. The approach was implemented in an ecoregional assessment of the British Columbia Central Interior. Regional strategies to reduce climate vulnerability were applied to set conservation targets and goals in the site-selection process. These had a wide-ranging impact on both freshwater and terrestrial conservation assessments. Selection of high-priority areas based on climate strategies generally (1) increased the number, size, and connectivity of selected areas, (2)...
The Nature Conservancy of Canada recently completed a project to identify priority watersheds for... more The Nature Conservancy of Canada recently completed a project to identify priority watersheds for conservation action in British Columbia’s Central Interior and Sub-Boreal Interior ecoprovinces. These watersheds will be focus areas for conservation action to protect freshwater ecosystems and species. Conservation planning techniques described in this article include determining conservation targets and goals, identifying these targets with coarse- and fine-filter approaches, and using Marxan software to identify priority watersheds for conservation actions such as land purchase and management actions. Methods to incorporate connectivity within freshwater ecosystems are also discussed, along with methodsto include climate change in broad-scale conservation planning. We identify 2257 priority watersheds within the Central Interior and Sub-Boreal Interior ecoprovinces, covering 33% of the freshwater analysis study area.
Lesbian, Gay, Bisexual, Transgender and Queer Resources in the Princeton University Library Book ... more Lesbian, Gay, Bisexual, Transgender and Queer Resources in the Princeton University Library Book Reviews on LGBT Themes
International Journal of Radiation Biology, May 16, 2022
BACKGROUND Estimates of radiation risks following prolonged exposures at low doses and low-dose r... more 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, 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 1,654 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 =0.062). 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 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 industrial radiographers, will enable more precise estimates of radiation risks at relatively low cumulative doses.
Ionizing radiation is an established carcinogen, but its effects on non-malignant respiratory dis... more Ionizing radiation is an established carcinogen, but its effects on non-malignant respiratory disease (NMRD) are less clear. Cohorts exposed to multiple risk factors including radiation and toxic dusts conflate these relationships, and there is a need for clarity in previous findings. This systematic review was conducted to survey the body of existing evidence for radiation effects on NMRD in global nuclear worker cohorts. A PubMed search was conducted for studies with terms relating to radiation or uranium and noncancer respiratory outcomes. Papers were limited to the most recent report within a single cohort published between January 2000 and December 2020. Publication quality was assessed based upon UNSCEAR 2017 criteria. In total, 31 papers were reviewed. Studies included 29 retrospective cohorts, one prospective cohort, and one longitudinal cohort primarily comprising White men from the U.S., Canada and Western Europe. Ten studies contained subpopulations of uranium miners or millers. Papers reported standardized mortality ratio (SMR) analyses, regression analyses, or both. Neither SMR nor regression analyses consistently showed a relationship between radiation exposure and NMRD. A meta-analysis of excess relative risks (ERRs) for NMRD did not present evidence for a dose-response (overall ERR/Sv: 0.07; 95% CI: –0.07, 0.21), and results for more specific outcomes were inconsistent. Significantly elevated SMRs for NMRD overall were observed in two studies among the subpopulation of uranium miners and millers (combined n = 4229; SMR 1.42–1.43), indicating this association may be limited to mining and milling populations and may not extend to other nuclear workers. A quality review showed limited capacity of 17 out of 31 studies conducted to provide evidence for a causal relationship between radiation and NMRD; the higher-quality studies showed no consistent relationship. All elevated NMRD SMRs were among mining and milling cohorts, indicating different exposure profiles between mining and non-mining cohorts; future pooled cohorts should adjust for mining exposures or address mining cohorts separately.
BackgroundFor occupational medical screening programs focused on long‐term health surveillance, p... more BackgroundFor occupational medical screening programs focused on long‐term health surveillance, participant attrition is a significant barrier to success. We investigate demographic, medical history, and clinical data from National Supplemental Screening Program (NSSP) examinees for association with likelihood of return for a second exam (rescreening).MethodsA total of 15,733 individuals completed at least one NSSP exam before December 31, 2016; of those, 4832 also completed a second exam on or before December 31, 2019. Stepwise logistic regression models were used to identify variables associated with whether a participant was rescreened in the NSSP.ResultsIndividuals were less likely to return for rescreening if they had a history of any cancer; cardiovascular problems; diabetes or kidney disease; or if they used insulin. Age at time of first exam and job site category significantly influenced likelihood of return. Workers categorized as “guests” were more likely to return. Partic...
According to the US Bureau of Labor Statistics, the average age of retirement is 62. While many r... more According to the US Bureau of Labor Statistics, the average age of retirement is 62. While many retirees may have employer-provided or other access to healthcare, others have limited access to affordable care until full Medicare eligibility at 65. Regardless of access, retirees with toxic occupational exposures may not have providers with specialized knowledge of tests or diagnoses for exposure-related health conditions, especially those with long-latency. The National Supplemental Screening Program for U.S. Department of Energy Former Workers is described here as a nationwide program providing recurring (every 3 years) integrated health screenings designed to identify both occupational and non-occupational conditions in the context of exposure so that early identification can enable appropriate and timely diagnoses and treatments to improve health outcomes. Since September 2005, there has been 18,518 initial exams for former workers, of whom 5,461 returned for rescreening exams thr...
Abstract Background During World War II (WWII), the Manhattan Engineering District established a ... more 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.
Ecoregional assessments provide a regional scale, biodiversity-based context for implementing con... more Ecoregional assessments provide a regional scale, biodiversity-based context for implementing conservation efforts by identifying a portfolio of sites for conservation action with a goal of protecting representative biodiversity and ecologically significant populations. The intent of these assessments is to create a shared vision for agencies and other organizations at the regional, state, and local levels to form partnerships and to ensure efficient allocation of conservation resources. The Nature Conservancy of Canada recently completed an ecoregional assessment of British Columbia’s Central Interior, the main components of which are presented as articles in this special issue of the BC Journal of Ecosystems and Management. These components include terrestrial ecosystems and animals, and freshwater ecosystems and species. The assessment also incorporates some new and innovative approaches to considering conservation priorities along with climate change, ecosystem services, and wil...
The Central Interior Ecoregional Assessment brought together professionals from the Nature Conser... more The Central Interior Ecoregional Assessment brought together professionals from the Nature Conservancy of Canada, provincial government ministries, and academic researchers, to complete a conservation-based scientific analysis of the Central Interior region of British Columbia. Four principal products emerged from this effort: conservation portfolios, Marxan summed solutions, conservation value maps, and a comprehensive compilation of conservation data for the ecoregion. With the completion of this assessment, NCC has developed conservation plans for the vast majority of British Columbia.
We present a vulnerability-based approach for considering climate as a threat in regional conserv... more We present a vulnerability-based approach for considering climate as a threat in regional conservation planning. The protocol is based on best available understanding of the climate sensitivity of species and systems of concern, has little reliance on climate or ecological change scenarios, and can be executed rapidly. This approach has advantages of (1) not being tied to environmental scenarios with high uncertainty and (2) generating ‘no regrets’ strategies for planning for climate in the context of other threats. The approach was implemented in an ecoregional assessment of the British Columbia Central Interior. Regional strategies to reduce climate vulnerability were applied to set conservation targets and goals in the site-selection process. These had a wide-ranging impact on both freshwater and terrestrial conservation assessments. Selection of high-priority areas based on climate strategies generally (1) increased the number, size, and connectivity of selected areas, (2)...
The Nature Conservancy of Canada recently completed a project to identify priority watersheds for... more The Nature Conservancy of Canada recently completed a project to identify priority watersheds for conservation action in British Columbia’s Central Interior and Sub-Boreal Interior ecoprovinces. These watersheds will be focus areas for conservation action to protect freshwater ecosystems and species. Conservation planning techniques described in this article include determining conservation targets and goals, identifying these targets with coarse- and fine-filter approaches, and using Marxan software to identify priority watersheds for conservation actions such as land purchase and management actions. Methods to incorporate connectivity within freshwater ecosystems are also discussed, along with methodsto include climate change in broad-scale conservation planning. We identify 2257 priority watersheds within the Central Interior and Sub-Boreal Interior ecoprovinces, covering 33% of the freshwater analysis study area.
Lesbian, Gay, Bisexual, Transgender and Queer Resources in the Princeton University Library Book ... more Lesbian, Gay, Bisexual, Transgender and Queer Resources in the Princeton University Library Book Reviews on LGBT Themes
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