Dr. Natalia (Natasha) Shilnikova is a Senior Health Risk Analyst at Risk Sciences International (RSI), where she has contributed since 2011 to some of the organization’s most analytically demanding and policy-relevant projects. With a background in medicine and a PhD in medical sciences, Dr. Shilnikova specializes in the synthesis of epidemiological evidence, human health risk assessment, toxicology, and critical literature reviews—applying her expertise across a spectrum of regulatory and public health priorities.

Todd Ruthman serves as Vice‑President, Software and Modelling Solutions at Risk Sciences International (RSI) and has been with RSI since its founding in 2006. With a BASc in Systems Design Engineering from the University of Waterloo, Todd strives to understand the complex interactions in systems - a perspective that he channels into the design of data-driven, evidence-based decision-support applications for RSI’s clients. His team crafts custom IT solutions and leverages tools such as SQL Server, .NET,  Python, Excel, and R, to translate complex risk scenarios into interactive decision-support platforms.

Dr. Paul Stanish joined Risk Sciences International (RSI) in 2021 as a Risk Analyst, where he plays an essential role in advancing data-driven risk practices. Leveraging his strong background in chemistry and nanotechnology, he supports clients in building modern data cultures grounded in causal inference, machine learning operations (MLOps), and organizational performance measurement. His work ensures that risk frameworks not only incorporate emerging technologies but are also scalable and operational within institutional settings.

Dr. Nataliya Karyakina is a Senior Toxicologist and Health Risk Analyst at Risk Sciences International (RSI), where she has served since 2008. She plays a central role in RSI’s work at the intersection of chemical safety, regulatory science, and human health. Drawing on more than three decades of experience, Dr. Karyakina contributes to complex projects involving the evaluation and assessment of hazardous properties of chemicals with different modes of action, hazard-based classification of chemical substances under CLP (EC) 1272/2008, and the development of health-based safety values for industrial and environmental chemicals for both workers and the general population.

Don Mattison's career is an amalgamation of medicine, science, and public service. He started with a Bachelor's degree in Chemistry and Mathematics, followed by a Master's from MIT in Chemistry. He then pivoted to medicine, obtaining an MD from Columbia University and focusing on pharmacology and toxicology in reproductive health during his residencies. Mattison has held several prestigious appointments, including Dean of the University of Pittsburgh's Graduate School of Public Health and Chief Medical Officer at Risk Sciences International. Throughout his career, he obtained medical licenses in six U.S. states and served in the U.S. Public Health Service, retiring with the rank of Captain. Most recently, he became a Distinguished Professor of Epidemiology at the University of South Carolina.

As a Microbiologist with Risk Sciences International, Dr. Sattar contributes his deep expertise in pathogen ecology, environmental microbiology, and infection control technologies to support RSI’s work in health risk assessment and risk mitigation. His insights guide RSI’s contributions to evidence-based disinfection strategies, microbial exposure modelling, and policy-relevant evaluations of infectious disease risk across water, air, food, and surface-contact pathways.

Dr. Franco Momoli joined Risk Sciences International (RSI) in 2019 and currently serves as Vice-President, Chemical and Product Safety. In this role, he leads a multidisciplinary team of epidemiologists, risk assessors, toxicologists, and biostatisticians in conducting human health risk assessments related to environmental contaminants and consumer products. His practice group supports government agencies, regulatory bodies, and international partners in making science-informed decisions that safeguard public health.

Dr. Cote is an Associate Expert at Risk Sciences International, where she brings world-class expertise in environmental health risk assessment, risk management, and science-informed public policy. She contributes to projects that require strategic application of risk methodologies to environmental, occupational, and chemical exposure issues—often at the intersection of regulation, sustainability, and health protection. Her work with RSI benefits from her deep understanding of both U.S. and international regulatory environments and her commitment to advancing decision-making through transparent and defensible science.

Dr. Tee L. Guidotti is an esteemed international consultant in occupational and environmental medicine, specializing in risk management and sustainability. His work encompasses problem-solving, medical evaluation, medicolegal services, and extensive publishing and writing. Although retired from the George Washington University, he maintains active roles in teaching and research, holding adjunct faculty positions at West Virginia University and the University of Alberta. His interests span energy technologies, firefighter health, climate change adaptation, and science policy. Dr. Guidotti's contributions include over 300 papers, eight books, and numerous awards, notably the Knudsen Award for Lifetime Achievement in Occupational and Environmental Medicine in 2013. His focus now centers on environmental sustainability and health.

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.