As a Senior Advisor and Associate Expert with Risk Sciences International, Dr. Leiss contributes unparalleled insight into the design, delivery, and evaluation of risk communication strategies for government, regulatory bodies, and civil society. His legacy work in building public trust around controversial science and his decades of thought leadership on consensus-building, science-based policy, and societal responses to risk make him a foundational contributor to RSI’s mission.

In Memoriam, Dr. Donald Mattison (1944-2026) Dr. Donald Mattison passed away at his home in Columbia, South Carolina on Sunday, March 22, with his family present. Don joined Risk Sciences International (RSI) in 2012 as Vice President and Chief Medical Officer, following a distinguished career spanning government, academia, and clinical practice in the United States. During his time at RSI, he contributed to 47 scientific publications and served as a trusted mentor and colleague to many across the organization.