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

The use of categorical regression in the assessment of the risks of nutrient deficiency and excess.


ABSTRACT

Exposure-response assessment methods have shifted towards more quantitative approaches, with health risk assessors exploring more statistically driven techniques. These assessments, however, usually rely on one critical health effect from a single key study. Categorical regression addresses this limitation by incorporating...
Publication details about The use of categorical regression in the assessment of the risks of nutrient deficiency and excess.

Systematic review in evidence-based risk assessment.


ABSTRACT

Systematic reviews provide a structured framework for summarizing the available evidence in a comprehensive, objective, and transparent manner. They inform evidence-based guidelines in medicine, public policy, and more recently, in environmental health and toxicology. Many regulatory agencies have extended and...
Publication details about Systematic review in evidence-based risk assessment.

Systemic quinolones and risk of retinal detachment III: a nested case-control study using a US electronic health records database.


ABSTRACT

BACKGROUND: Quinolones are popular antibiotics that are known for their potency, broad coverage, and reasonable safety. Concerns have been raised about a possible association between quinolones and retinal detachment (RD). METHODS: We conducted a nested case-control study using electronic health...
Publication details about Systemic quinolones and risk of retinal detachment III: a nested case-control study using a US electronic health records database.

Principles of risk decision-making.


ABSTRACT

Risk management decisions in public health require consideration of a number of complex, often conflicting factors. The aim of this review was to propose a set of 10 fundamental principles to guide risk decision-making. Although each of these principles is...
Publication details about Principles of risk decision-making.

Prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age: a systematic review and meta-analysis.


ABSTRACT

This study aims to quantify the difference in prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age through a systematic review and meta-analysis. Six electronic databases were searched from inception to August 31, 2021. Studies were...
Publication details about Prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age: a systematic review and meta-analysis.

Association between exclusive breastfeeding and postpartum post-traumatic stress disorder.


ABSTRACT

BACKGROUND: Research on the association between breastfeeding and postpartum post-traumatic stress disorder (PTSD) is sparse. This study aimed to examine the association between exclusive breastfeeding up to 42 days after childbirth and postpartum PTSD. METHODS: An epidemiologic study was conducted...
Publication details about Association between exclusive breastfeeding and postpartum post-traumatic stress disorder.

Treatment for grade 4 peripheral intravenous infiltration with type 3 skin tears: A case report and literature review.


ABSTRACT

Grade 4 peripheral intravenous infiltration with skin tears has seldom been reported. On 4 August 2020, a 35-year-old female patient was admitted to the emergency department of our hospital because of postprandial abdominal pain for 2 hours. She was diagnosed...
Publication details about Treatment for grade 4 peripheral intravenous infiltration with type 3 skin tears: A case report and literature review.

Systemic quinolones and risk of retinal detachment I: analysis of data from the US FDA adverse event reporting system.


ABSTRACT

BACKGROUND: Quinolones comprise a class of antibiotics that are globally preferred for treating a wide range of bacterial infections due to their potency, broad coverage, favorable pharmacologic profile, and mostly mild to moderate adverse reactions. Spontaneous reports on adverse drug...
Publication details about Systemic quinolones and risk of retinal detachment I: analysis of data from the US FDA adverse event reporting system.

Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study.


ABSTRACT

In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country...
Publication details about Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study.

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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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