Prior to joining the George Washington University School of Public Health and Health Sciences, Professor Gray served as the Assistant Administrator for the Office of Research and Development and the Science Advisor at the U.S. Environmental Protection Agency from 2005-2009. He also previously served as the Executive Director of the Harvard Center for Risk Analysis and a lecturer in Risk Analysis at the Harvard School of Public Health. Professor Gray earned a B.S. (Biology) from the University of Michigan and M.S. and Ph.D. (Toxicology) from the University of Rochester. Areas of research interest include nanotechnology, ecosystem research, the influence of toxicology advances on testing and risk assessment, and sustainability.