BEST Staff

Clifford Duke, Director
Phone: (202) 334-3591


Raymond Wassel, Scholar and Director of Environmental Studies
Phone: (202) 334-2617


Ellen Mantus, Scholar and Director of Risk Assessment
Phone: (202) 334-2347


Susan Martel, Senior Program Officer for Toxicology
Phone: (202) 334-2021


Elizabeth Boyle, Program Officer
Phone: (202) 334-2228


Tamara Dawson, Program Associate
Phone: (202) 334-2776


Jessica Wolfman, Senior Program Assistant
Phone: (202) 334-3536


Laura Llanos, Financial Associate
Phone: (202) 334-3067


Clifford S. Duke joined the academies in September 2018 as the Director of the Board on Environmental Studies and Toxicology. Cliff previously served as Director of Science Programs at the Ecological Society of America, a position he held since 2003. In this position, he was responsible for developing and managing a portfolio of activities to promote the development of ecological sciences and its integration into decision-making and education. During his time at ESA, Cliff developed and managed a wide range of activities for federal and state agencies, professional societies, and the scientific community, including the society's Sustaining Biological Infrastructure Program; a review of Vegetation Monitoring and Analytical Methods for Owens Valley, CA; a six year Program on Biofuels and Sustainability; and a series of projects on managing natural history collections. Cliff has also served as a member of the National Academies' Committee on Sustainable Development of Algal Biofuels and the Board on Research Data and Information. Cliff received his undergraduate degree in biology and environmental studies from the University of Vermont and both his M.A. in public policy science and Ph.D. in botany from Duke University.


Elizabeth Barksdale Boyle, MPH, CIH, has over 15 years of experience in environmental health and epidemiology. She currently works as a Program Officer on the Board on Environmental Studies and Toxicology within the Academies Division on Earth and Life Studies. Formerly, she was an Environmental Health Scientist at Westat, where she supported the Environmental Protection Agency, the National Institute of Child Health and Development, and the National Cancer Institute by completing other environmental epidemiology related projects. Prior to her tenure at Westat, Ms. Boyle was a student epidemiologist at the Minnesota Department of Health and an Industrial Hygienist at a consulting firm in Cincinnati. She serves as Chair of the Nominations Committee for the International Society of Exposure Science. She is also a fellow of the Bloomberg American Health Initiative at Johns Hopkins University Bloomberg School of Public Health where she is pursuing a doctor of public health in environmental health. Ms. Boyle has an MPH in Environmental Epidemiology, a BS in Biology, and she is a Certified Industrial Hygienist.


Ellen Mantus is a Scholar and Director of Risk Assessment on the Board on Environmental Studies and Toxicology at the National Academies of Sciences, Engineering, and Medicine with over 20 years of experience in toxicology and risk assessment. She has served as the study director on numerous projects, including ones that have assessed the health implications of various chemical exposures, developed strategies for applying modern scientific approaches in toxicology and risk assessment, provided guidance to federal agencies on risk-based decision-making, and evaluated barriers to deployment of electric vehicles and associated charging infrastructure. Before joining the National Academies, Dr. Mantus was a project manager with ICF Consulting where she served as a primary reviewer for numerous toxicological studies and provided risk assessment and regulatory support on a wide array of projects. Dr. Mantus received a PhD in chemistry from Cornell University in Ithaca, NY.


Susan Martel is a Senior Program Officer in the Board on Environmental Studies and Toxicology at the National Academies of Sciences, Engineering and Medicine. She has 20 years of experience in supporting toxicology and risk assessment projects for the US Environmental Agency, the Department of Defense, and the National Aeronautics and Space Administration. Recent projects include working with committees evaluating the toxicological effect of arsenic, developing exposure guidelines for use on spacecraft, and assessing pesticide risks-assessment practices. Before joining the Academies she was the administrator of the Registry for Toxicology Pathology for Animals at the American Registry of Pathology. She received her BA in biology from Skidmore College.


Ray Wassel is a scholar and director of environmental studies within the Board on Environmental Studies and Toxicology. He develops and manages studies that provide advice concerning many aspects related to environmental science and engineering. Since he joined the National Academies in 1987, Ray has substantially contributed to the completion of more than 50 reports on issues involving emissions control, environmental behavior of pollution, air quality management, hazardous-waste and radioactive-waste management, exposure science, health and ecological risk assessment and management, environmental economics, regulatory science, sustainability, safety performance of industrial processes and transportation systems, and research management.  Prior to joining the National Academies, Ray was a staff engineer with Radian Corp (an environmental consulting firm) in Research Triangle Park, NC, where he supervised projects in support of U.S. EPA programs to characterize industrial air pollution sources and to estimate control costs and control effectiveness. While undertaking graduate studies at the University of Virginia, he carried out a two-year study of acid mine drainage effects on microbial communities in a freshwater lake. Prior to his graduate work, Ray monitored ecologic trends near a nuclear power plant on the shore of Lake Ontario.  Ray received an M.S. degree in environmental science and an M.S. degree in chemical engineering from the University of Virginia in Charlottesville. He received a B.A. in biology from Canisius College in Buffalo, NY. He received an Individual Distinguished Service Award in 2007 for special contribution to the missions and vision of the National Academies.


Tamara Dawson is a Program Coordinator for the Board on Environmental Studies and Toxicology. She began working for the National Academy of Sciences, Engineering, and Medicine in the Fall of 2002. Tamara has worked in the event coordination field for almost 20 years. In fact, before arriving at NAS, she worked with the team that administers the PAEMST program for NSF. In her spare time, Tamara enjoys spending time with family, traveling and distance running.


Jessica Wolfman is a Senior Program Assistant for the Board on Chemical Sciences and Technology and the Board on Environmental Studies and Toxicology. She joined the Academies in August of 2017. Jessica graduated Phi Beta Kappa from Dickinson College in May of 2017 with a Bachelor of Science in Earth Sciences and a minor in Mathematics.


Laura Llanos is a Financial Associate with the Board on Environmental Studies and Toxicology.  She started working at the National Academies of Sciences, Engineering, and Medicine in 1998.  In 2006, she became the Financial and Administrative Associate for the Radiation Effects Research Foundation (RERF) Program, which is managed through the Nuclear and Radiation Studies Board.  She is the recipient of several individual and group awards including the National Academies' Individual Distinguished Service Award for her work on the RERF program.