Dr. Pierson served as Professor of Food Microbiology and Safety at Virginia Polytechnic Institute and State University 1970-2005, Head of the Department of Food Science and Technology 1985-1994, and Acting Superintendent of the Center for Seafood Extension and Research 1992-1994. He has published more than 150 referred research articles and seven books on food safety and quality in addition to presenting numerous workshops on HACCP and food safety management. He served as United States Department of Agriculture (USDA) Deputy Under Secretary for Food Safety 2002-2004, and Acting Under Secretary for Food Safety 2004-2005. In these positions he had responsibility for overseeing the Food Safety Inspection Service and the U.S. Codex Alimentarius office. In addition, he provided leadership as Chair of the USDA National Advisory Committee on Microbiological Criteria for Foods and the US government Codex Alimentarius Policy Committee. From 2005 to 2008 he served as USDA’s Deputy Under Secretary for Research, Education, and Economics.  In this position, he provided leadership and policy direction for the Agricultural Research Service; the Cooperative State Research, Education, and Extension Service; the Economic Research Service; and the National Agricultural Statistics Service. He was appointed Chairman of the General Administration Board of Graduate School, USDA 2006-2009; Chairman of the Board of Trustees for the Graduate School USA 2009-2021; and currently serves as Chair of the Board of Trustees of the Public Service Education Institute.