Dr. Mark A. Williams is a Biologist (Immunotoxicologist) and Project Manager for the Ecotoxicology Assessment Program in the Toxicology Directorate – Health Effects Division of the U.S. Army Public Health Center at Aberdeen Proving Ground, MD.  Dr. Williams has previously served as a Research Biologist at the U.S. Environmental Protection Agency (U.S. EPA), with research interests in allergic asthma, and environmental exposures to particulate matter and nano-pollutants. Prior to joining the U.S. EPA, Dr. Williams was an Assistant Professor of Medicine and Environmental Medicine at the University of Rochester School of Medicine and Dentistry, and an Instructor of Medicine at the Johns Hopkins University School of Medicine.

Dr. Williams holds primary degrees in Biotechnology and Bioengineering, as well as Molecular Cell Biology and Immunology. He holds a Ph.D. in Hematological Oncology and Tumor Immunology from Queen Mary College of the University of London, U.K., and has conducted post-doctoral training at the University of California at San Diego (UCSD), La Jolla, CA, and the Johns Hopkins University School of Medicine in Baltimore. Dr. Williams is a Fellow of the American Academy of Allergy, Asthma and Immunology (AAAAI). Dr. Williams is a frequent external grant reviewer for NASA and their Atmospheric, Earth and Environmental Health Research Panels, and currently serves as the Non-VA Federal Government Chair of a Gulf War Exposures and Health Effects Working Group.  In his spare time, Dr. Williams serves as the Editor in Chief of the peer-reviewed journal Drug and Chemical Toxicology and is a member of the Regular Editorial Board of Toxicology Letters, and several others.