Timothy J. Jorgensen is associate professor of Radiation Medicine, and Director of the Health Physics and Radiation Protection Graduate Program, at Georgetown University in Washington DC. His scientific expertise is in radiation biology, cancer epidemiology, and public health. He is board certified in public health by the National Board of Public Health Examiners (NBPHE). He serves on the National Council on Radiation Protection (NCRP), he chairs the Georgetown University Radiation Safety Committee, and he is an associate in the Epidemiology Department at the Bloomberg School of Public Health at the Johns Hopkins University. His research interests include the genetic determinants of cellular radiation resistance, and the genes that modify the risk of cancer. He lives with his family in Rockville, Maryland.