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...
Read More about Environmental Public Health Approach (EPHA) to Chemicals Expert Workshop

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...
Read More about Systematic Review of Artificial Sweeteners and Health Risks

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...
Read More about Evaluation of Health Product Risk Communication Tools

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...
Read More about Evaluation of Drug Recall Communication and Risk Determination Processes

Publications associated with Daniel Krewski

Relevance and feasibility of principles for health and environmental risk decision-making.


ABSTRACT

Globally, national regulatory authorities are both responsible and accountable for health and environmental decisions related to diverse products and risk decision contexts. These authorities provided regulatory oversight and expedited market authorizations of vaccines and other therapeutic products during the COVID-19...
Publication details about Relevance and feasibility of principles for health and environmental risk decision-making.

Interventions for COVID-19 Vaccine Hesitancy: A Systematic Review and Narrative Synthesis.


ABSTRACT

Vaccines effectively protect against COVID-19, but vaccine hesitancy and refusal hinder vaccination rates. This systematic review aimed to (1) review and describe current interventions for addressing COVID-19 vaccine hesitancy/refusal and (2) assess whether these interventions are effective for increasing vaccine...
Publication details about Interventions for COVID-19 Vaccine Hesitancy: A Systematic Review and Narrative Synthesis.

Effects of vaginal microbiota transfer on the neurodevelopment and microbiome of cesarean-born infants: A blinded randomized controlled trial.


ABSTRACT

The microbiomes of cesarean-born infants differ from vaginally delivered infants and are associated with increased disease risks. Vaginal microbiota transfer (VMT) to newborns may reverse C-section-related microbiome disturbances. Here, we evaluated the effect of VMT by exposing newborns to maternal...
Publication details about Effects of vaginal microbiota transfer on the neurodevelopment and microbiome of cesarean-born infants: A blinded randomized controlled trial.

Disproportionality analysis of adverse neurological and psychiatric reactions with the ChAdOx1 (Oxford-AstraZeneca) and BNT162b2 (Pfizer-BioNTech) COVID-19 vaccines in the United Kingdom.


ABSTRACT

BACKGROUND: Information on neurological and psychiatric adverse events following immunization (AEFIs) with COVID-19 vaccines is limited. RESEARCH DESIGN & METHODS: We examined and compared neurological and psychiatric AEFIS reports related to BNT162b2 (Pfizer-BioNTech) and ChAdOx1 (Oxford-AstraZeneca) COVID-19 vaccines and recorded...
Publication details about Disproportionality analysis of adverse neurological and psychiatric reactions with the ChAdOx1 (Oxford-AstraZeneca) and BNT162b2 (Pfizer-BioNTech) COVID-19 vaccines in the United Kingdom.

The incidence of post-traumatic stress disorder following traumatic childbirth: A systematic review and meta-analysis.


ABSTRACT

BACKGROUND: Although birth trauma may be a risk factor for postpartum post-traumatic stress disorder (PTSD), no systematic review regarding the incidence of postpartum PTSD in women with traumatic childbirth has been reported. OBJECTIVE: To estimate the incidence of PTSD in...
Publication details about The incidence of post-traumatic stress disorder following traumatic childbirth: A systematic review and meta-analysis.

Risk of myocarditis and pericarditis in mRNA COVID-19-vaccinated and unvaccinated populations: a systematic review and meta-analysis.


ABSTRACT

OBJECTIVE: To summarise the available evidence on the risk of myocarditis and/or pericarditis following mRNA COVID-19 vaccination, compared with the risk among unvaccinated individuals in the absence of COVID-19 infection. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Electronic databases (Medline,...
Publication details about Risk of myocarditis and pericarditis in mRNA COVID-19-vaccinated and unvaccinated populations: a systematic review and meta-analysis.

Concomitant use of statins and sodium-glucose co-transporter 2 inhibitors and the risk of myotoxicity reporting: A disproportionality analysis.


ABSTRACT

AIMS: Recent case reports have suggested that sodium-glucose co-transporter 2 (SGLT2) inhibitors may interact with statins to increase their risk of myotoxicity. We assessed the risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins. METHODS: We...
Publication details about Concomitant use of statins and sodium-glucose co-transporter 2 inhibitors and the risk of myotoxicity reporting: A disproportionality analysis.

Myocarditis and Pericarditis Post-mRNA COVID-19 Vaccination: Insights from a Pharmacovigilance Perspective.


ABSTRACT

Concerns remain regarding the rare cardiovascular adverse events, myocarditis and pericarditis (myo/pericarditis), particularly in younger individuals following mRNA COVID-19 vaccination. Our study aimed to comprehensively assess potential safety signals related to these cardiac events following the primary and booster doses,...
Publication details about Myocarditis and Pericarditis Post-mRNA COVID-19 Vaccination: Insights from a Pharmacovigilance Perspective.

Adjusting for Berkson error in exposure in ordinary and conditional logistic regression and in Poisson regression.


ABSTRACT

BACKGROUND: INTEROCC is a seven-country cohort study of occupational exposures and brain cancer risk, including occupational exposure to electromagnetic fields (EMF). In the absence of data on individual exposures, a Job Exposure Matrix (JEM) may be used to construct likely...
Publication details about Adjusting for Berkson error in exposure in ordinary and conditional logistic regression and in Poisson regression.

Search all publications

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...
News article about Evidence-based Risk Assessment Framework

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...
News article about Value of information

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

A few more images...