SC 1-26: Approaches for Integrating Radiation Biology and Epidemiology for Enhancing Low Dose Risk Assessment


NCRP Report No. 171, Uncertainties in the Estimation of Radiation Risks and Probability of Causation (2012) discussed the impact of the several uncertainties in the available epidemiology data and in the approaches used to extrapolate from these data to estimate adverse outcomes at low radiation doses and dose rates. NCRP Commentary No. 24, Health Effects of Low Doses of Radiation: Perspectives on Integrating Radiation Biology and Epidemiology (2015) reviewed the available data on low dose effects at the whole animal, cellular and molecular levels and how these might be integrated into a single approach with epidemiology data. The proposed approach built upon that used in the field of risk assessment for environmental chemicals, namely to develop adverse outcome pathways (AOPs) for radiation-induced cancer and noncancer effects and to identify the key events along such pathways. Key events are envisaged to be used as parameters in biologically-based dose-response (BBDR) models for estimating risks at low doses and dose rates. Simple and sophisticated BBDR models have been developed over a number of years but as knowledge of the etiology of adverse outcomes has been greatly enhanced in the past few years, more and more realistic and predictive models have and can be developed. In addition, there is a quite extensive resource available for the application of the AOP/key rvent approach as applied to the risks from exposure to environmental chemicals. At the same time, additional radiation epidemiology data are becoming available that will significantly enhance the predictive outcome of any integrated models. In particular, data from the so-called “Million Person Study” will come available shortly and over the next several years. These data will serve as a critical component of any BBDR modeling approach for estimating radiation risks at low doses and low dose rates.


The Committee will comprehensively review the types of data that constitute key events for specific radiation-induced adverse outcomes (cancer and noncancer) and how critical ones might be developed through a targeted research program. The most informative epidemiology data for an integrated approach will be identified and, if not available, how these too might be obtained. The available BBDR models will be reviewed for assessing their value to the current task and equally their limitations. In this context, new predictive models will be proposed together with the parameters that could be used for propagating such models. Research for defining adverse outcome pathways and for obtaining reliable key events (parameters) will be proposed. The Committee will therefore, extend the concepts and approaches discussed in NCRP Report No. 171 and Commentary No.24 to further reduce uncertainty in radiation risk assessments at low doses and low dose rates, thereby enhancing the bases for radiation protection standards.


To prepare a report that describes available or potential approaches for combining data from epidemiology and radiation biology studies into models for predicting low dose/low dose rate radiation risks.

Scheduled Activities

First meeting November 29-30, 2017





recently retired as the Associate Director for Health for the National Health and Environmental Effects Research Laboratory of the U.S. Environmental Protection Agency (EPA). He also served as Director of the Environmental Carcinogenesis Division at EPA and as senior science adviser at the Chemical Industry Institute of Toxicology. He has been employed at the Biology Division of the Oak Ridge National Laboratory and has served as associate director for the Oak Ridge–University of Tennessee Graduate School for Biomedical Sciences. Dr. Preston's research and current activities have focused on the mechanisms of radiation and chemical carcinogenesis and the approaches for incorporating these types of data into cancer risk assessments.

Dr. Preston was chair of Committee 1 of the International Commission on Radiological Protection (ICRP), a member of the ICRP Main Commission, and a member of the U.S. delegation to the United Nations Scientific Committee on the Effects of Atomic Radiation. He is an associate editor of Environmental and Molecular Mutagenesis, Mutation Research, Chemico-Biological Interactions, and Health Physics. Dr. Preston has had more than 200 peer-reviewed papers and chapters published. He received his BA and MA from Peterhouse, Cambridge University, England, in genetics and his PhD from Reading University, England, in radiation genetics. He has served on the National Research Council's Committee to Assess the Scientific Information for the Radiation Exposure Screening and Education Program and the Task Group on the Biological Effects of Space Radiation.

r. julian preston, Chairman

Werner Rühm

is Acting Director of the Institute of Radiation Protection and leads the Medical and Environmental Dosimetry Group at the Helmholtz Center Munich, Germany. In addition he is professor at the Medical Faculty of the University of Munich.

Dr. Rühm has been a member of Committee 1 (C1) of the International Commission on Radiological Protection (ICRP) since 2005. He served as C1 Secretary from 2012 to 2016, and has continued as C1 Chair since 2016. He was a member of ICRP Task Group (TG) 83 (Protection of Aircraft Crew Against Cosmic Radiation Exposure), and is currently chairing ICRP TG91 on Dose and Dose-Rate Effectiveness Factor. Since 2005 he has served as Editor-in-Chief of the Radiation and Environmental Biophysics journal. In 2014 he was elected Chair of the European Radiation Dosimetry Group (EURADOS), and in 2017 was appointed as a member of the German Radiation Protection Commission (SSK), and as Co-chair of the SSK Committee on Radiation Risk. He has published on various topics including quantification of neutron exposure of atomic-bomb survivors, cosmic-ray exposure of air crew, the role of neutrons in risk assessment of atomic-bomb survivors, risks from low-dose-rate exposures, behaviour of radionuclides in the environment, internal exposures from incorporated radionuclides, and radiation measurement techniques.

Werner Rühm, Co-Chair



Edouard I. Azzam is Professor in the Department of Radiology at Rutgers University - New Jersey Medical School. He received his doctoral degree in the field of radiation biology from the University of Ottawa (Canada) in 1995. From 1995 to 2000, he pursued post-doctoral studies at the Harvard School of Public Health under the mentorship of Professor John B. Little.

His research program has focused on elucidating the mechanisms underlying the biological effects of low doses/low fluences of ionizing radiations that differ in their biophysical characteristics. The goal is to elucidate the role of intercellular communication and oxidative metabolism in radiation-induced nontargeted effects and adaptive responses. The outcome of these investigations may be significant towards reducing the uncertainty associated with current models for predicting the long-term health risks of exposure to radiation. His studies have been funded by the National Institutes of Health, the National Aeronautics and Space Administration, and the U.S. Department of Energy; and they have resulted in the training of numerous students and post-doctoral fellows who remain engaged in unraveling the biochemical events underlying the responses of human cells to ionizing radiation.

edouard i. azzam

Simon Bouffler

is currently the Head of Radiation Effects Department at the Public Health England (PHE) Centre for Radiation, Chemical and Environmental Hazards. He has held several appointments at PHE and its predecessor organisations, the Health Protection Agency and National Radiological Protection Board, since 1991. Previously he held a post-doctoral research position in the Department of Zoology, University of Cambridge. Dr. Bouffler’s research interests focus on the biological mechanisms of radiogenic diseases utilising mouse models and human cellular systems.

Dr. Bouffler is the U.K. representative to the United Nations Scientific Committee on the Effects of Atomic Radiation and has served on the U.K. delegation since 2006. He was recently elected to the Main Commission of the International Commission on Radiological Protection (ICRP) having served as Vice-Chair of ICRP’s Committee 1 from 2013 to 2017. He has published over 100 peer reviewed papers.

Dr. Bouffler was educated at the University of Southampton, receiving a BSc and PhD in Biology.

Simon Bouffler

Mark P. Little

Littleis a Senior Investigator with the National Cancer Institute, Radiation Epidemiology Branch (REB). He studied mathematics at Trinity College, Cambridge and obtained his doctorate in mathematics at New College, Oxford. Over the last two decades he has been analyzing cancer and cardiovascular disease risks in the Japanese atomic-bomb survivors, and in other irradiated populations and offspring. Dr. Little has explored mechanistic models of carcinogenesis and cardiovascular disease in populations exposed to ionizing radiation and cigarette smoke. His statistical interests also include the effects of measurement error on regression estimates. Previously, he worked in the Imperial College Department of Epidemiology and Biostatistics, and before that at U.K. National Radiological Protection Board (now part of the Public Health England). He has served as consultant to the United Nations Scientific Committee on the Effects of Atomic Radiation for the recently completed cancer epidemiology document, to the International Atomic Energy Agency, to the U.K. Committee on the Medical Aspects of Radiation in the Environment, and to NCRP Scientific Committee 1-21. In REB, Dr. Little is working on assessment of thyroid cancer risk in various cohorts of persons exposed as result of the Chernobyl nuclear reactor accident, on risks of various health endpoints in the U.S. cohort of radiologic technologists, on treatment-related second cancer risks in various populations, focusing on dose measurement error and gene-radiation interaction. He has a particular interest in risks at low doses and dose rates, specifically in relation to childhood leukemia and circulatory disease.

Mark P. Little


was a Professor and Chief of the Epidemiology Division at New York University School of Medicine before going to the Radiation Effects Research Foundation (RERF) in Hiroshima-Nagasaki as Vice Chairman and Chief of Research. He is an author of ~100 radiation-related publications and is currently working with other RERF investigators on studies of radiation and various diseases.

He has served on numerous governmental and scholarly committees, including as a long-time member of the International Commission on Radiological Protection and NCRP, and has served on various committees or task groups for the United Nations Scientfic Committee on the Effects of Atomic Radiation, the World Health Organization, the National Academy of Sciences, the National Cancer Institute, and the U.S. Environmental Protection Agency, among others. His interests include the effects of radiation on both cancer and noncancer disease incidence, and understanding the epidemiologic and biological modification of radiation effects by various environmental, genetic and age factors.

roy e. shore

Igor Shuryak

is an assistant professor in the Center for Radiological Research, Department of Radiation Oncology at Columbia University Medical Center. His research interests focus on mechanistic mathematical modeling of the effects of ionizing radiation on living organisms. They include modeling of radiation-induced carcinogenesis at both low and high doses (e.g., second cancers induced by radiotherapy for primary malignancies), cancer therapy (e.g., tumor control and normal tissue complications), nontargeted (“bystander”) effects of radiation (e.g., for densely-ionizing radiation exposures such as those occurring on manned space missions), and mechanisms of resistance to ionizing radiation in human and nonhuman cells.

Dr. Shuryak’s training and experience have been interdisciplinary, starting with biology (BA from Columbia University) and medicine (MD from State University of New York Downstate College of Medicine). He received a PhD degree with distinction from the Department of Environmental Health Sciences (Columbia University, Mailman School of Public Health) for work on combing both short- and long-term time scales in mechanistic modeling of radiation-induced carcinogenesis.

Igor Shuryak



is a professor in the Department of Environmental and Radiological Health Sciences at Colorado State University (CSU). His research, which takes advantage of murine models of radiation carcinogenesis and leukemogenesis, is focused on understanding how radiation exposure can lead to cancer and why some individuals may be more susceptible than others. At CSU, Dr. Weil teaches a graduate level course in cancer genetics and lectures in courses on cancer biology, environmental carcinogenesis, principles of radiation biology, and the pathobiology of laboratory animals.

Dr. Weil earned his PhD in Microbiology from the University of Texas at Austin and was trained in cancer genetics and radiation biology in the Department of Biochemistry and Molecular Biology Biochemistry and the Department of Experimental Radiotherapy at the University of Texas M.D. Anderson Cancer Center. Dr. Weil is a Radiation Research Society council member and has served on National Institutes of Health, U.S. Department of Defense, and National Aeronautics and Space Administration grant review panels.

michael m. weil



is the Director for the Center of Science and Technology in the Radiation Protection Division, U.S. Environmental Protection Agency (EPA). He has been at EPA since 1985, heading a group with responsibility for developing models for EPA's assessment of radiation doses and risks. From 1982 to 1998, he worked on similar issues at the U.S. Nuclear Regulatory Commission (NRC). Prior to this, he was first a Postdoctoral Fellow and then a faculty member in the Department of Radiation Biology and Biophysics at the University of Rochester, where he performed research on ion transport into mitochondria and ion binding to phospholipid membranes. His academic degrees include a BA from Johns Hopkins and a PhD from Harvard, both in Physics. He has represented EPA on a number of interagency committees, including a committee established to advise on health protection measures for the U.S. population after Chernobyl and the Executive Committees for the Committee on Interagency Radiation Research and Policy Coordination and the Joint Coordinating Committee for Radiation Effects Research.

He served on the scientific committee (SC) for NCRP Report No. 160, Ionizing Radiation Exposure of the Population of the United States and is currently a member of the NCRP SC 1-20, which is addressing the issue of enhanced relative biological effectiveness for low-energy photons and electrons. He was also a member of a committee of experts who developed the "Late Health Effects Uncertainty Assessment" component for the Probability Accident Consequence Uncertainty Analysis, a joint report of NRC and the Commission of the European Communities.

jerome s. puskin, Staff Consultant
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Last modified: October 16, 2017