David Richardson is associate professor of epidemiology in the School of Public Health at the University of North Carolina, Chapel Hill. His research focuses on the health effects of occupational and environmental exposures, particularly with regards to ionizing radiation. He has conducted studies of cancer among nuclear workers at several US Energy Department facilities and studied cancer among the Japanese survivors of the atomic bombings of Hiroshima and Nagasaki. He has served as a visiting scientist at the World Health Organization’s International Agency for Research on Cancer in Lyon, France, and at the Radiation Effects Research Foundation in Hiroshima, Japan. He is an associate editor of the journals Occupational and Environmental Medicine, American Journal of Epidemiology, and Environmental Health Perspectives. He is a member of the President’s Advisory Board on Radiation and Worker Health, and he serves on the Institute of Medicine’s Committee on Review of the Department of Labor’s Site Exposure Matrix Database.