WPM-A - Million Person Study and Agency Perspectives on Importance of Occupational Epidemiology Woodrow Wilson A 14:30 - 17:00
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| Chair(s): Isaf Al-Nabulsi, David Bierman
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WPM-A.1
14:30 The Million Person Study of Low-Level and Low-Dose-Rate Health Effects: Importance, Information and Innovation LT Dauer*, Memorial Sloan Kettering Cancer Center
; D Bierman, Memorial Sloan Kettering Cancer Center; JD Boice, Jr., NCRP
Abstract: The study of humans exposed to low doses and low-dose rates is essential 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. The presentation will include brief review of the purpose for studying one million U.S. radiation workers and veterans, the general methodology, status, and selected results (including dose response analyses for risks of cancer, heart disease, and Parkinson’s disease, amongst others), planned expansion, and vision then concentrate on the MPS’ innovations in all areas of epidemiological study as a de facto National Center for Radiation Epidemiology and Biology, including 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 including multiple stressors, harmonization across cohorts, use of Centers for Medicare & Medicaid Services linkages, big data extraction and mining, and multi-model evaluations.
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WPM-A.2
14:45 Million Person Study (MPS) Rocky Flats: Epidemiologic Analyses and Comparison to Other Department of Energy Cohorts AP Golden*, ORAU
; SC Howard, ORAU; CE Samuels, ORNL; RL Leggett, ORNL; KF Eckerman, Easterly Scientific; MT Mumma, International Epidemiology Institute; Vanderbilt Medical Center; LT Dauer, Memorial Sloan Kettering Cancer Center; JD Boice, NCRP; Vanderbilt University
Abstract: Background: The Million Person Study (MPS) is comprised of numerous individual cohorts utilizing similar approaches for tracing, dosimetry, and analyses to achieve harmonization for pooled studies. This presentation highlights the results from a recently updated cohort, the Rocky Flats (RF) plant, a US Department of Energy (DOE) plutonium processing facility operating 1951-1989. Results of this analysis are also compared with other MPS cohorts with similar exposures.
Methods: The RF cohort includes 9,397 workers hired before 1980 and working at least 30 days. Organ doses were calculated from all sources of radiation exposure including, photons, neutrons, Pu-238, Pu-239, Pu-241, Am-241, Am-241 progeny, and uranium. Since beryllium is an important co-exposure for RF, data from the DOE Beryllium Surveillance Program was obtained for evaluation. Vital status through 2017 was ascertained through multiple sources including the National Death Index, Social Security Administration, and state death files. Statistical analyses include standardized mortality ratios and Cox proportional hazard models.
Results: Workers were primarily white (95.7%), male (83.5%), and with high school education or less (60.0%). Nearly 90% of workers had radiation monitoring where highest mean doses (radiation dose weighting factor = 1) of 58.2 mGy (SD: 109.4) for lung and 54.4 (SD: 102.6) mGy for bone were observed to be similar to those from the MPS Los Alamos National Laboratory cohort. More than half were deceased with most common causes of ischemic heart disease (n=999), non-malignant respiratory disease (n=436), lung cancer (n=361) and cerebrovascular disease (n=237). Preliminary dose-response analyses indicate little evidence for increased risk from fractionated, low doses, similar to findings in other MPS cohorts. Nearly 40% of workers were monitored for beryllium, with indication of beryllium sensitization or disease for 6% (n=563). A non-significant indication of confounding by beryllium exposure was observed for lung cancer risk.
Conclusion: Additional analyses are needed to assess the risk of mortality from radiation exposure in the RF cohort, with particular attention to potential confounding by beryllium exposure, and to pool these results with similar MPS cohorts to improve statistical precision.
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WPM-A.3
15:00 NASA Perspectives on Importance of Occupational Epidemiology Data SR Blattnig*, NASA
Abstract: Radiation is one of the primary risk factors to human health that provides an obstacle to the safe exploration of space, consisting of high energy charged particles and resulting particle fragments from collisions with materials in spacecraft and the human body. Approximately 0.5 Gy (1 Sv) of exposure would be expected from a Mars mission. The health risks of primary concern from space radiation exposure are cancer, cardiovascular and central nervous system diseases. NASA’s strategy to mitigate such risks currently consists of the development of permissible exposure limits that effectively limit the time individuals spend in space, shielding, and research into biomedical countermeasures. There is a need to understand and quantify these health risks to counter them cost effectively. A primary basis for understanding and quantifying radiation responses in humans is radiation epidemiology, which is integrated with animal and other experimental data to develop risk models. These risk models can then be used to evaluate and optimize mitigations strategies.
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WPM-A.4
15:15 DOE Perspectives on Importance of Occupational Epidemiology I. Al-Nabulsi*, DOE
Abstract: The Department of Energy (DOE) and its predecessors have a long history in conducting and supporting radiation epidemiological studies since shortly after the Manhattan Project began in 1942 through to the present day. The Radiation Exposure Monitoring System serves as the central repository of occupational radiation exposure records. DOE epidemiology studies are informed by personnel, employment, medical, radiation exposure, and facility records. The Comprehensive Epidemiologic Data Resource provides open access to data from the DOE epidemiological studies program. DOE has supported all aspects of the Million Person Study (MPS) since the feasibility study in 2009-2010, funded by the Office of Science and now by the Office of Environment, Health, Safety and Security. The MPS can provide valuable research findings to improve DOE former worker medical screening and compensation programs, and to enhance protection of current radiation workers.
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WPM-A.5
15:30 Break
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WPM-A.6
16:00 The Department of Defense Perspective On The Importance Of Radiation Epidemiology PK Blake*, DoD-Retired
Abstract: The Department of Defense (DoD) currently monitors ~70,000 DoD workers annually for ionizing radiation exposure. The DoD radiation monitoring infrastructure includes three nationally accredited external personal radiation dosimetry programs (Army, Navy, and Air Force), a variety of internal personal monitoring programs, various environmental and food radiological analysis labs, and five radiation dose repositories with records on over 2 million individuals (Atomic Veterans (1945-1992), Army/National Guard, Navy/Marines, Air Force, and Operation Tomodachi Registry (OTR)). DoD dose repositories also include Coast Guard and Merchant Marine exposures and non-DoD visitor exposures. There have been numerous radiation epidemiology studies of these workers, including the DoD cohorts in ongoing Million Person Study. Radiation epidemiology studies are important to DoD in: (1) understanding the impact of ionizing radiation exposures on the health & safety of our DoD-affiliated population, (2) addressing the credibility of DoD’s radiation safety programs, and (3) providing a technical basis for associated radiogenic disease compensation and veteran recognition programs.
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WPM-A.7
16:15 Perspectives of the U.S. Nuclear Regulatory Commission EV Holahan*, US NRC
Abstract: The U.S. Nuclear Regulatory Commission (NRC) is an independent agency created by Congress to regulate the Nation’s civilian commercial, industrial, academic, and medical uses of nuclear materials. The agency licenses and regulates the civilian use of radioactive materials to provide reasonable assurance of adequate protection of public health and safety to promote the common defense and security, and to protect the environment. The NRC is responsible for the development of regulations and guidance that set requirements for: dose limits for radiation workers and members of the public; monitoring and labeling radioactive materials; posting radiation areas; and reporting the theft/loss of radioactive material. The current NRC regulatory framework is based on three central assumptions: a linear non-threshold dose response relationship for stochastic outcomes, that the severity of a stochastic effect is independent of the amount of radiation dose received, and that there is an apparent threshold for non-stochastic effects. NRC also recognizes that there is uncertainty in the magnitude of the risk at very low doses and low dose rates. High quality occupational epidemiological studies have been and continue to be essential for informing current and future policy development.
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WPM-A.8
16:30 The EPA Perspectives on Importance of Radiation Epidemiology A Ansari*, U.S. Environmental Protection Agency
Abstract: The practice of radiation protection is based on application of scientific data, together with consideration for ethical principles and societal factors, to provide for health and safety of workers, and members of the public including at-risk populations. During the last hundred years, we have learned a great deal about the biological effects of radiation on cellular and animal models, characterizing its mutagenic and carcinogenic effects in these experimental systems. EPA radiation protection regulations and guidance are informed by what we know about risk of exposure at low doses and dose rates and uncertainties of those estimates. While direct observation of human health effects by epidemiologic means at low doses remains highly challenging, use of biologically based dose response models can supplement epidemiological data and enhance the estimation of health risks. High quality epidemiological studies inform our radiation protection and public health practices.
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WPM-A.9
16:45 Perspectives on the Importance of Radiation Epidemiology in Radiological Emergency Preparedness A Salame-Alfie*, Centers for Disease Control and Prevention
; A Chang, Centers for Disease Control and Prevention
Abstract: The need for nuclear/radiological emergency preparedness cannot be overstated as a nuclear/radiological incident could happen anytime, anywhere, and will likely impact all sectors. The United States Centers for Disease Control and Prevention (CDC) has recognized the need for radiation-savvy public health staff to fulfill their roles and responsibilities quickly in response to a nuclear/radiological incident and has instituted the Nuclear/Radiological Training and Exercise Preparedness program (TEP) to meet this need. Through this program, CDC has trained several hundred staff across the various Centers, Institutes and Offices (CIOs) and has participated in several National Level Exercises including, most recently, the Cobalt Magnet 2022 exercise that took place in May 2022.
CDC continues to encourage high quality epidemiology studies to support public health decision making (see -https://www.cdc.gov/nceh/radiation/emergencies/radiation-epidemiology-videos.htm for additional information) and being radiation-savvy includes an understanding of the importance of and outcomes and implications of radiation epidemiology studies of workers and populations, as those studies will help inform the criteria to be used to identify cohorts for long-term medical follow-up.
Disclaimer - The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention
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