WPM-B - Special Session: DOE Health Studies Part 2 Centennial Ballroom 300B 14:30 - 17:45
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| Chair(s): Isaf Al-Nabulsi, Ashley Golden
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WPM-B.1
14:30 U.S. Transuranium and Uranium Registries: 2010 – 2022 Research Accomplishments and Collaborative Efforts SY Tolmachev*, U.S. Transuranium and Uranium Registries, Washington State University
Abstract: The United States Transuranium and Uranium Registries (USTUR), and the associated National Human Radiobiology Tissue Repository (NHRTR), is a federal-grant program funded by U.S. Department of Energy and operated by College of Pharmacy and Pharmaceutical Sciences at Washington State University in Richland, Washington, USA. The Registries was established in 1968 to study the biokinetics and internal dosimetry of actinides (uranium, plutonium, and americium) in occupationally-exposed Registrants who volunteered portions of their bodies, or their whole bodies, for scientific use posthumously. The USTUR is the only program worldwide that can comprehensively study biokinetics and dosimetry of internally deposited actinides. The USTUR serves as a source for both scientific research and public information regarding the biokinetics and tissue dosimetry of the actinide elements in humans. Since 1992, eight PhD and eight MS students have used USTUR data to complete the research requirements of their studies. Currently, USTUR research focuses on: (i) estimation of uncertainties in radiation dose assessment for internally deposited actinides, (ii) biokinetic modeling of individual cases, (iii) development of actinide chelation models, (iv) study of post-mortem distribution of actinides in the human body, and (v) study of occupational exposure to non-radioactive materials associated with the nuclear industry. The USTUR core operational functions are: (i) accepting and processing Registrant donations, (ii) completing radiochemical analysis of donated tissue samples, and (iii) completing the development and population of the USTUR databases. Currently, the Registries holds records and data for 364 deceased and 22 living Registrants. The USTUR/NHRTR data and materials are available to qualified scientists for their research upon request. The USTUR maintains well-established collaborations with national and international scientists and institutions, and develops new collaborative relationships. Since its establishment, the USTUR has published over 350 peer-reviewed manuscripts, and has contributed to six National Council on Radiation Protection and Measurements reports and nine International Commission on Radiological Protection publications.
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WPM-B.2
14:55 Uncertainties in Radiation Dose Assessment for Internally Deposited Plutonium in Support of Radiation Epidemiology M Sefl*, U.S. Transuranium and Uranium Registries, Washington State University
; JY Zhou, U.S. Department of Energy; M Avtandilashvili, U.S. Transuranium and Uranium Registries, Washington State University; SL McComish, U.S. Transuranium and Uranium Registries, Washington State University; G Tabatadze, U.S. Transuranium and Uranium Registries, Washington State University; SY Tolmachev, U.S. Transuranium and Uranium Registries, Washington State University
Abstract: Since its establishment in 1968, the United States Transuranium and Uranium Registries (USTUR) has received 317 partial- and 47 whole-body donations for scientific research from former nuclear workers who had accidental intakes of actinide radionuclides. These individuals typically have well-documented work history, exposure, bioassay monitoring, and medical records. Among 349 cases with completed radiochemical analysis, 59 cases with recorded 239Pu intake(s) were selected for evaluation of uncertainties in the radiation dose assessment for radiation epidemiology. These individuals were not extensively treated with chelation therapy and had at least five 239Pu urine measurements exceeding the contemporary detection limit, as well as 239Pu concentrations in the skeleton and liver greater than 0.1 Bq kg-1 and 1 Bq kg-1, respectively. The objectives were to compare: (i) predicted 239Pu activities in the skeleton and liver, based upon urine bioassays, with measured post-mortem activities in the skeleton and liver; (ii) dose estimates calculated from urine data alone with those based on both urine data and post-mortem radiochemical analyses. Taurus internal dosimetry software was used to model individual cases using default ICRP biokinetic model assumptions. Biases for the predicted and measured post-mortem organ activities and calculated radiation doses were studied as a pilot study of 11 former Manhattan Project workers. Current biokinetic model predictions for the liver+skeleton retention appear to be on average within 5% of the measured organ activities. On the other hand, the use of early urine bioassay data collected during the exposure period in the 1940s overestimated the liver+skeleton activity on average by a factor of 2.5. This demonstrates the importance of a long-term collection of bioassays as a part of follow-up. Analysis of the remaining cases are in progress.
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WPM-B.3
15:10 Beryllium in Tissues of Former Nuclear Workers M Avtandilashvili*, U.S. Transuranium and Uranium Registries, Washington State University
; D Larivière, Laval University, Canada; N Momoshima, Kyushu Environmental Evaluation Association, Japan; D Wegge, University of Missouri – Columbia; JD Brockman, University of Missouri – Columbia; SY Tolmachev, U.S. Transuranium and Uranium Registries, Washington State University
Abstract: Beryllium and beryllium compounds widely used in nuclear power industry and weapons production are known to be human carcinogens. Currently, there is limited published data on beryllium concentrations and distribution in the human body. The US Transuranium and Uranium Registries (USTUR), established in 1968 to study the biokinetics and internal dosimetry of actinides by following up former nuclear workers with documented intakes of these elements, who volunteered their bodies for scientific use posthumously, holds detailed work history, radiation exposure, and industrial hygiene records including self-reported information on beryllium exposure. Out of 364 deceased USTUR Registrants, 92 self-reported working with beryllium, but only 73 individuals reported years of beryllium work ranging from 1 to 45 years with the average of 17 ± 13 years. Beryllium concentrations were measured using inductively-coupled plasma mass spectrometry in tissue samples from 13 USTUR cases with beryllium exposure duration ranging from 3 to 39 years. A total of 149 tissues was analyzed including 105 tissues from a whole-body donor who was potentially exposed to beryllium for 6 years. The highest concentrations were measured in thoracic lymph nodes with the range of 6 – 334 µg kg-1 (median: 59.1 µg kg-1). For other tissues, beryllium median concentration followed the order: liver (6.84 µg kg-1) > kidney (0.55 µg kg-1) > lung (0.30 µg kg-1) > skeleton (0.16 µg kg-1). For analyzed whole-body case, the total beryllium content was estimated to be 54.8 µg, including 5.8 µg retained in the respiratory tract 22 years post-exposure. It was found that systemic beryllium primarily accumulated in the skeleton (27.3 µg), followed by the liver (11.3 µg) and other soft tissues (10.4 µg). Beryllium concentration in the liver (10.2 µg kg-1) was three times higher than the average concentration in the skeleton (3.0 µg kg-1) and 42 times higher than that in other soft tissues (0.24 µg kg-1).
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WPM-B.4
15:25 Plutonium bioassay models for reconstruction of doses for Los Alamos National Laboratory and Rocky Flats workers CE Samuels*, ORNL Center for Radiation Protection Knowledge
; RW Leggett, ORNL Center for Radiation Protection Knowledge
Abstract: As part of the Million Person Study, ORNL performed dose reconstructions for plutonium workers at Los Alamos National Laboratory (LANL) and Rocky Flats. At LANL about 2000 workers had positive bioassays for Pu-238 and/or Pu-239. At Rocky Flats about 4000 workers had positive bioassays for Pu-239. Dose reconstructions were based on latest biokinetic models of the International Commission of Radiological Protection (ICRP), or site-specific variations of those models. In addition to extensive urinary excretion data, the LANL database included autopsy data for 28 workers and a database of incidents resulting in potentially elevated intake of Pu. In addition to urinary Pu data, the database for Rocky Flats included autopsy data for 25 workers as well as estimated lung contents of Pu for over 500 workers based on external measurements of Am-241. One or more inhalation absorption types for each LANL or Rocky Flats worker was selected based on curve fits to urinary data for LANL and urinary plus lung data, when available, for Rocky Flats. Where feasible, a cumulative excretion curve for a worker was derived from 24-hour urinary excretion measurements using trapezoidal integration. The shape of the cumulative excretion curve over the period of urine measurements often provided insight into the solubility of inhaled Pu, with a nearly linear or concave upward climb of cumulative excretion indicating a relatively insoluble form of Pu and a concave downward curve indicating a more soluble form. The dose reconstruction techniques will be described and results for both sites will be summarized.
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WPM-B.5
15:50 Break
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WPM-B.6
16:05 Reconstruction of Lung Doses for the Tennessee Eastman Corporation MB Bellamy*, MSKCC
; L Dauer, MSKCC; K Eckerman, ORNL (Retired)
Abstract: The Tennessee Eastman Corporation was involved in uranium enrichment between 1943 and mid-1947. Workers were exposed to airborne dust consisting mainly of relatively insoluble uranium compounds resulting in alpha irradiation of the lungs. Annual lung radiation doses associated with the inhaled uranium were estimated for each study member. Time and location-based uranium air monitoring measurements were used to estimate airborne uranium concentrations. Worker employment records were linked to air monitoring measurements to determine worker-specific uranium dust concentrations, subsequently used to determine time-dependent intakes between 1943 and 1947. The estimated mean absorbed dose to the lung from uranium dust inhalation was 32.7 mGy (max. 1048 mGy) for women and 18.5 mGy (max. 501 mGy) for men. This session presents methods and results associated with imputing doses for workers based on work histories and estimating lung dose and associated uncertainties based on chronic uranium inhalation conditions.
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WPM-B.7
16:30 Impact of the Department of Energy’s Comprehensive Epidemiologic Data Resource (CEDR) to the Million Worker Study SC Howard*, Oak Ridge Institute for Science and Education
; AP Golden, Oak Ridge Institute for Science and Education; ED Ellis, Oak Ridge Institute for Science and Education; DJ Girardi, Oak Ridge Institute for Science and Education
Abstract: The United States Department of Energy (DOE) has supported epidemiologic studies of possible radiation and chemical induced health effects since the 1960s. While many of these studies have been reported in the scientific literature, the Comprehensive Epidemiologic Data Resource (CEDR) was created by DOE as a way to further support epidemiologic research efforts by providing a publicly available repository for the previously published data. Currently, CEDR houses data produced from over 77 studies covering one million workers. Included in the CEDR datasets are de-identified demographic data, radiation-monitoring data, mortality outcomes, and environmental exposure data. Although differences exists in the available datasets, generally the radiation monitoring data is provided as film badge readings, bioassays for internal emitters, radon breath measurements, and area dust samples. For the Million Worker Study (MWS), which studies the health effects associated with chronic low-dose radiation exposure in one million United States workers and veterans, CEDR is a valuable resource. For many of the cohorts, including the recently published Los Alamos National Laboratory and Tennessee Eastman Corporation cohorts, datasets published on CEDR provided the initial information required to begin building a cohort. This session will detail how the data available on CEDR is used in the MWS, as well as provide an overview of CEDR itself.
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WPM-B.8
16:55 Findings from Department of Energy Cohorts in the Million Worker Study: Los Alamos National Laboratory, Rocky Flats Site, and Tennessee Eastman Corporation AP Golden*, Oak Ridge Institute for Science and Education
; JD Boice, Jr., Vanderbilt University; National Council on Radiation Protection and Measurements; SC Howard, Oak Ridge Institute for Science and Education; SC Cohen, Epidstat; MT Mumma, Vanderbilt University; IEI; MB Bellamy, Memorial Sloan Kettering Cancer Center; LT Dauer, Memorial Sloan Kettering Cancer Center; C Samuels, Oak Ridge National Laboratory; EF Eckerman, Oak Ridge National Laboratory - retired; RW Leggett, Oak Ridge National Laboratory
Abstract: The Million Worker Study (MWS) is a retrospective cohort study assessing the mortality of over one million United States workers and veterans who were chronically exposed to low-dose radiation. This session will describe recent findings from Department of Energy (DOE) cohorts within the MWS. The Los Alamos National Laboratory (LANL) cohort includes 26,328 workers (25% females) who were first employed in 1943-1980 and who worked at least 30 days. The Tennessee Eastman Corporation (TEC) cohort includes 26,650 workers (52% females) were employed in 1943-1947 for at least 90 days. The Rocky Flats Plant (RFP) cohort includes 9,397 workers (16% females) 7 who were first employed in 1952-1970 for at least 30 days. For each o the 62,275 workers in these cohorts, organ dose estimates were based on all sources of exposure. These sources varied across cohorts but included exposures to gamma radiation (all), neutrons (LANL, RFP, and intakes of uranium (TEC), plutonium (LANL), or both (RFP).
Lung cancer was of primary concern because of the relatively high intakes of radionuclides. The mean lung doses, assuming a Dose Weighting Factor of 20 for uranium and plutonium, were 28.6 weighted-mGy for LANL, 591 weighted-mGy for TEC, and >197 weighted-mGy for RFP.
The sex-adjusted ERRs (95% CI) for lung cancer at 100 weighted-mGy for LANL, TEC, and RFP were 0.01 (-0.02, 0.03; n=839), -0.005 (-0.01. 0.001; n=1,654), and 0.01 (-0.01, 0.02; n= 361). There was no evidence that female and male workers had different estimates of radiation-related lung cancer risk. Additional findings from these and other DOE cohorts will be discussed.
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WPM-B.9
17:20 The Million Person Study of Low-Level and Low-Dose-Rate Health Effects: Importance, Information and Innovation LT Dauer*, Memorial Sloan Kettering Cancer Center
; JD Boice, Jr., NCRP and Vanderbilt University Medical Center
Abstract: 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 of Low-Level and Low-Dose-Rate Health Effects (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. Over a million healthy American workers and veterans are being studied to evaluate cancer and non-cancer mortality and morbidity following low-level low-LET and high-LET exposure, rare cancers, intakes of radioactive elements, and differences in risks between women and men. Overall, 34 individual cohorts comprise the MPS. This presentation will provide an overview of the scientific approach for MPS, using specific cohorts and investigations as examples. Discussion will include the purpose for studying one million U.S. radiation workers and veterans, the general methodology, status, selected results (including dose response analyses for risks of cancer, heart disease, and Parkinson’s disease, amongst others), as well as the planned expansion and vision. As a National Center for Radiation Epidemiology and Biology, the MPS continues to be in incubator for innovation in all areas of epidemiological study, including unique vital status and tracing activities, new science for radiation dosimetry methodologies, evaluation of cognition-related outcomes in addition to other cancer and non-cancer impacts, harmonization across cohorts, use of Centers for Medicare & Medicaid Services linkages, big data extraction and mining, and multi-model evaluations.
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