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.

Sean Hart is RSI’s Finance Officer and Bookkeeper, where he manages the company’s core financial operations and supports project-level accounting. With a strong command of both accounting principles and digital systems, Sean ensures the integrity, accuracy, and compliance of RSI’s financial records and reporting.

Dr. Paul Price is a Senior Analyst at Risk Sciences International (RSI), bringing over four decades of experience as a pioneer in exposure science and chemical risk assessment. Since joining RSI in 2019, Dr. Price has focused on advancing mixture risk assessment—an increasingly vital area as regulators shift from assessing single chemicals in isolation to understanding the cumulative effects of combined exposures. His current work includes the development of Mixture Adjustment Factors, participation in international regulatory committees, and authorship of scholarly publications aimed at refining the science-policy interface of chemical mixture risk.

Daniel Krewski began his career in the federal government of Canada, focusing on programs within Health Canada, particularly in food safety and environmental health. Trained in mathematics, statistics, and biostatistics, his multidisciplinary background reflects the complex nature of risk science. He later transitioned to academia, founding the McLaughlin Centre for Population Health Risk Assessment at the University of Ottawa. There, he developed new methodologies and collaborated internationally. In 2006, he co-founded Risk Sciences International, aiming to provide expert advice on diverse risk issues. His contributions have been instrumental in shaping risk assessment frameworks used by organizations like Health Canada and the U.S. Environmental Protection Agency. In 2023, Dr. Krewski passed the CEO's baton to Greg Paoli; he remains active as RSI Chief Risk Scientist.

Dr. Al-Zoughool has maintained a long-standing relationship with Risk Sciences International, both as a scientific collaborator and as a co-investigator on complex international projects. His work with RSI focuses on high-level public health risk modeling, mechanistic data analysis, and toxicological risk assessment of major environmental contaminants in air, soil, and water, including formaldehyde, lead, and 1,4-dioxane. His research also extends to methodological innovation and the development of evidence-based strategies for environmental and occupational health policy.

Monique MacDonald is a seasoned Office Administrator with over thirty-five years of experience ensuring the smooth and efficient operation of office environments. She joined Risk Sciences International (RSI) in 2017, where she oversees the full range of internal operations and provides essential support across RSI’s scientific, operational, and client engagement activities. Her responsibilities include bookkeeping, financial support such as budgeting, invoicing, and expense tracking, as well as sales and marketing support. She also serves as operational and logistics coordinator for RSI’s convening events, including training sessions, workshops, and meetings.

Dr. Michael G. Tyshenko is a Senior Health Risk Analyst at Risk Sciences International (RSI), where he has contributed since 2018 to some of the organization’s most complex and cross-cutting public health risk projects. As RSI’s lead on chemical peer reviews, he brings extensive experience in regulatory science, biological risk, and science-policy integration to high-stakes evaluations that require both deep expertise and clear communication.

Hong Duan is a Systems Analyst and Application Developer at Risk Sciences International, where she has applied her expertise since 2011. She holds a Bachelor of Computer Science degree from the University of Ottawa and is certified as a Microsoft .NET Professional Developer. Hong specializes in developing database-driven, risk-based web applications.

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. 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.