RSI's Daniel Krewski - Official portrait

Dr. Daniel Krewski

FSRA, PhD, MHA

Chief Risk Scientist

Joined RSI in 2006

  • Global thought leader in risk science

  • Expert in public and population health

  • 20+ years experience in Federal Government of Canada

  • Professor of epidemiology at University of Ottawa since 1998

  • Research contributions influencing health policy

Dr. Daniel Krewski is Chief Risk Scientist and co-founder of Risk Sciences International (RSI), a firm established in 2006 to bring evidence-based, multidisciplinary expertise to the challenge of understanding, managing, and communicating risk. As RSI’s inaugural CEO and long-time scientific leader, Dr. Krewski helped define the company’s ethos and methodological approach, grounded in rigorous, transparent, and policy-relevant science.

Under his leadership, RSI has become an international reference point in risk science, advising public and private sector organizations on issues ranging from chemical exposure and public health to advanced toxicity testing, infectious disease modeling, and environmental protection. He has served as RSI’s scientific anchor across dozens of high-profile engagements—among them, work for the U.S. Environmental Protection Agency, Health Canada, the Alliance of Blood Operators, and the Pan American Health Organization.

Although now retired as CEO, Dr. Krewski continues in his role as Chief Risk Scientist, where he contributes to RSI’s most complex risk assessment mandates and supports long-term innovation in the company’s scientific strategy. His work at RSI continues to bridge regulatory application with academic inquiry, and he remains a prolific contributor to RSI publications and tools, including frameworks for next-generation toxicity testing and comparative risk modeling.

He has played key roles in RSI projects addressing risks as varied as mad cow disease, carbon capture and storage, air pollution, climate change, neurological disorders, and pandemic influenza. Across these efforts, his expertise in quantitative modeling, risk communication, and structured expert judgment has helped shape not just organizational practices, but international standards in risk evaluation.

Dr. Krewski’s ongoing relationship with academic institutions—particularly the University of Ottawa—has allowed RSI to maintain strong ties to research frontiers. His joint appointments foster a model of knowledge transfer that benefits RSI’s clients and contributes to training the next generation of risk scientists through mentorship, graduate education, and real-world project integration.

Pre-RSI

Daniel Krewski’s pioneering role in the field of risk science began well before the discipline gained formal recognition. Trained first in mathematics, then in statistics, and ultimately in biostatistics with applications in toxicology and epidemiology, his career has always been at the intersection of quantitative analysis and human health. This multidisciplinary pathway reflects the inherently integrative nature of modern risk science.

He began his professional journey in the Federal Government of Canada, where he served for over 20 years, primarily within Health Canada. There, he worked across a spectrum of risk-related domains—food safety, environmental health, toxicological risk evaluation—collaborating with bench scientists, regulatory evaluators, legislative advisors, and public policy experts. These experiences shaped his enduring focus on pragmatic, science-based solutions to protect population health.

In 1998, Dr. Krewski joined the University of Ottawa as a Professor in the School of Epidemiology and Public Health, where he quickly distinguished himself as both a teacher and research leader. At the university, he founded the McLaughlin Centre for Population Health Risk Assessment, modeled after the Harvard Center for Risk Analysis. The Centre became a leading institution for Canadian risk science, fostering national and international collaborations and serving as a hub for innovative methods in risk assessment and management.

During this period, Dr. Krewski was instrumental in helping to develop foundational risk assessment frameworks for both Health Canada and the U.S. Environmental Protection Agency. He contributed to the evolution of regulatory risk practice, building on the insights from landmark efforts like the U.S. National Research Council’s “Red Book” and later publications on toxicity testing and comparative exposure analysis.

His academic initiatives included the creation of Canada’s first graduate program in risk science, providing structured education for a new generation of interdisciplinary risk professionals. He also served as scientific lead or co-lead on numerous large-scale research initiatives and policy collaborations, including systematic reviews on neurological disease, lung cancer burden, and chemical health impacts, and helped structure national responses to emerging risks like bovine spongiform encephalopathy (BSE) and chronic wasting disease.

Through these pre-RSI roles, Dr. Krewski laid much of the groundwork for RSI’s eventual founding, bringing a blend of government experience, academic leadership, and global thought leadership that would come to define the firm’s identity.


Daniel Krewski, in addition to his many hours spent teaching at the University of Ottawa, is regularly asked to speak including this presentation given during the National Cancer Institute Directors' meeting in Lyon.

Case studies associated with Daniel Krewski

Environmental Public Health Approach (EPHA) to Chemicals Expert Workshop

PROJECT DESCRIPTION

To advance the Government of Canada’s Chemicals Management Plan (CMP), a virtual expert workshop was planned and hosted to refine and evaluate a Canadian framework for the Environmental Public Health Approach (EPHA) to chemicals. The initiative focused on developing case...
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Systematic Review of Artificial Sweeteners and Health Risks

PROJECT DESCRIPTION

A comprehensive systematic review was undertaken to assess experimental evidence regarding the potential health risks associated with artificial sweeteners, specifically focusing on cancer and pre-term delivery. The client sought a rigorous analysis of both in vivo and in vitro experimental...
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Evaluation of Health Product Risk Communication Tools

PROJECT DESCRIPTION

To enhance the effectiveness of health product risk communications, a systematic evaluation was requested to assess the performance of key instruments used to disseminate safety and efficacy information. The aim was to support efforts under the Evaluating the Effectiveness of...
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Evaluation of Drug Recall Communication and Risk Determination Processes

PROJECT DESCRIPTION

In response to public and ministerial concerns about the timeliness and adequacy of information shared during a major prescription drug recall, Health Canada commissioned an independent review to assess its response to the event. The situation involved a recall of...
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Publications associated with Daniel Krewski

A multi-level analysis of risk factors for Schistosoma japonicum infection in China.


ABSTRACT

OBJECTIVE: The aim of this study was to explore the risk factors of schistosomiasis japonica in China, using a hierarchical multi-level model with individuals nested within villages. METHODS: A cross-sectional survey of schistosomiasis japonica was conducted in 16 villages in...
Publication details about A multi-level analysis of risk factors for Schistosoma japonicum infection in China.

Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants.


ABSTRACT

In this report we review the health effects of three short-lived greenhouse pollutants-black carbon, ozone, and sulphates. We undertook new meta-analyses of existing time-series studies and an analysis of a cohort of 352,000 people in 66 US cities during 18...
Publication details about Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants.

The psychosocial and socioeconomic consequences of bovine spongiform encephalopathy (BSE): a community impact study.


ABSTRACT

The detection of the first indigenous case of bovine spongiform encephalopathy (BSE) in Canada on May 20, 2003, had significant consequences for the livestock industry. As a result, borders were closed by several trade partners, particularly the United States. The...
Publication details about The psychosocial and socioeconomic consequences of bovine spongiform encephalopathy (BSE): a community impact study.

Recent oral contraceptive use and adverse birth outcomes.


ABSTRACT

OBJECTIVE: To examine the possible association between oral contraceptive use and adverse birth outcomes. STUDY DESIGN: We conducted a population-based cohort study of pregnant women who used oral contraceptives within 3 months before their last menstrual period. Subjects were divided...
Publication details about Recent oral contraceptive use and adverse birth outcomes.

Cardiovascular mortality and exposure to airborne fine particulate matter and cigarette smoke: shape of the exposure-response relationship.


ABSTRACT

BACKGROUND: Fine particulate matter exposure from both ambient air pollution and secondhand cigarette smoke has been associated with larger risks of cardiovascular mortality than would be expected on the basis of linear extrapolations of the relative risks from active smoking....
Publication details about Cardiovascular mortality and exposure to airborne fine particulate matter and cigarette smoke: shape of the exposure-response relationship.

International case studies of psychosocial ripple effects of bovine spongiform encephalopathy (BSE) in European countries.


ABSTRACT

The public is increasingly concerned about risks associated with food. Food-borne diseases can easily mobilize public concerns and create strong emotional, behavioral, and political reactions with significant negative economic and psychosocial outcomes. This was observed in various countries globally experiencing...
Publication details about International case studies of psychosocial ripple effects of bovine spongiform encephalopathy (BSE) in European countries.

Extended follow-up and spatial analysis of the American Cancer Society study linking particulate air pollution and mortality.


ABSTRACT

We conducted an extended follow-up and spatial analysis of the American Cancer Society (ACS) Cancer Prevention Study II (CPS-II) cohort in order to further examine associations between long-term exposure to particulate air pollution and mortality in large U.S. cities. The...
Publication details about Extended follow-up and spatial analysis of the American Cancer Society study linking particulate air pollution and mortality.

Low dose ionizing radiation exposure and cardiovascular disease mortality: cohort study based on Canadian national dose registry of radiation workers.


ABSTRACT

OBJECTIVES: The purpose of our study was to assess the risk of cardiovascular disease (CVD) mortality in a Canadian cohort of 337 397 individuals (169 256 men and 168 141 women) occupationally exposed to ionizing radiation and included in the...
Publication details about Low dose ionizing radiation exposure and cardiovascular disease mortality: cohort study based on Canadian national dose registry of radiation workers.

Does leptin play a role in obesity-asthma relationship?


ABSTRACT

The increase of asthma has paralleled the rising obesity during the past decades. Obesity is characterized by the increase of leptin in the circulation. Leptin is an obesity gene product, and it can stimulate the production of pro-inflammatory mediators, such...
Publication details about Does leptin play a role in obesity-asthma relationship?

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RSI News associated with Daniel Krewski

Aging and cognitive decline

Working with the College of Physicians and Surgeons of Alberta, Risk Sciences International conducted a wide-ranging review of aging and cognitive decline, with specific focus on aging physicians and fitness to practice.  The publication in Aging & Mental Health documents domains of cognition that decline with older age, concerns with...
News article about Aging and cognitive decline

Evidence-based Risk Assessment Framework

Working with international thought leaders in risk science, Risk Sciences International investigators contributed to the development of the evidenced-based risk assessment framework shown in the figure below.  The framework evolved from a workshop held at the University of Ottawa in December 2018, jointly organized by the McLaughlin Centre for Population Health Risk...
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Value of information

Risk Sciences International (RSI) investigators Greg Paoli, Shintaro Hagiwara and Daniel Krewski collaborated with investigators from the US Center for Computational Toxicology and Exposure (CCTE) on the development of an analytical framework to evaluate alternative chemical toxicity testing strategies, meeting a need identified by the US National Research Council in...
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Quinolones and risk of retinal detachment

Following previous work on the potential risk of acute liver failure associated with quinolone antibiotics, RSI investigators, Mohamed Taher, Franco Momoli, Donald Mattison and Daniel Krewski evaluated the potential risk of retinal detachment (RD) associated with these medications. Although no cases of RD were linked to quinolones in clinical trials, some...
News article about Quinolones and risk of retinal detachment

Bias Assessment in Case-Control and Cohort Studies for Hazard Identification

IARC recently published a volume on quantitative bias modelling: Bias assessment in case–control and cohort studies for hazard identification (IARC Scientific Publication No. 171). We are pleased to see inclusion of some of the work RSI's Drs Franco Momoli and Daniel Krewski conducted for the INTERPHONE and MOBI-Kids studies of...
News article about Bias Assessment in Case-Control and Cohort Studies for Hazard Identification

Outside RSI

Beyond his extraordinary professional accomplishments, Dr. Daniel Krewski is a passionate mentor, energetic speaker, and multitalented individual with a strong connection to both scientific and civic life. Over the course of his career, he has supervised dozens of graduate students and postdoctoral researchers, many of whom have gone on to lead public health, environmental safety, and risk science programs across Canada and internationally.

He remains deeply engaged in the academic community as Scientific Director of the McLaughlin Centre and as a senior member of faculty at the University of Ottawa, where he contributes to program development, scientific advisory boards, and expert panels. He frequently participates in peer-review committees, conference keynote sessions, and collaborative projects with regulatory and research agencies worldwide.

Known for his clarity of thought and collegial manner, Dr. Krewski is often described by colleagues as a principled scientist—someone who communicates with humility, leads through consensus, and uses evidence to advance public well-being.

Yet his interests are far from limited to risk science.

He is a prolific amateur photographer, responsible for documenting RSI’s visual history and for capturing many of the natural stone sculptures and other imagery featured on RSI’s materials and website. His love of photography reflects a lifelong attention to detail and composition—qualities that mirror his scientific mindset.

A resident of Ottawa, Dr. Krewski also enjoys wine tasting, stone sculpture, and performance driving, having participated in programs such as the Ford Performance Racing School in North Carolina. He is equally at home leading a Zumba class on Parliament Hill as he is reviewing national environmental policy; his personal vitality and balance make him a compelling presence across settings.

Through these extracurricular pursuits, Dr. Krewski brings humanity, curiosity, and creativity to everything he does—reinforcing his role not only as a global thought leader in risk science but as a vibrant contributor to Canada’s cultural and academic life.

Teaching Zumba with Co-instructors Sharon and Iryna

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