Substance use and work
With the legalization of recreational cannabis in Canada, questions have been raised about patterns of cannabis use at work, the use of cannabis to treat work-related injuries, and the implications of such uses for work productivity, workplace health and safety and work disability management. IWH research examines these questions, as well as questions about the use and effectiveness of narcotics or opioids to treat pain, including pain associated with work injuries, and patterns of opioid-related harms among workers.
Featured

Research Highlights
Severe pain, not pressure to return to work or lack of accommodation offer, linked to opioid use post-injury
An IWH study found that among a group of injured workers in Ontario, those who experienced severe pain were more likely to use opioids than those who had no or only mild pain.
Published: February 12, 2025

Issue Briefing
Cannabis use by workers before and after legalization in Canada
Since 2018, when non-medical use of cannabis was legalized in Canada, a pair of Institute for Work & Health (IWH) studies was conducted to explore the implications of this change for workplaces. This briefing sums up their findings.
Published: December 5, 2024

IWH in the media
IWH, OCRC project delves into role of employment in opioid crisis
The number of people who die or who are being hospitalized due to opioids continues to rise, prompting the Institute for Work & Health (IWH) and the Occupational Cancer Research Centre (OCRC) to launch a research project monitoring opioid-related adverse health events in order to identify the worker groups most at risk. Angela Gismondi reports.
Published: Daily Commercial News, August 2022
Journal article
Journal article
Cannabis use and workplace cannabis availability, perceptions and policies among Canadian workers: a comparison before and after the legalisation of non-medical cannabis
Published: Occupational and Environmental Medicine, July 2022

At Work article
Cannabis use linked to higher injury risk, but only among those who use at or before work
Does the use of cannabis increase a worker’s risk of having a workplace injury? Previous studies have found mixed results, but none has looked specifically at the use of cannabis just before or at work.
Published: April 2022
IWH Speaker Series
IWH Speaker Series
Cannabis use and the risk of workplace injury: Findings from a longitudinal study of Canadian workers
Does the use of cannabis increase a worker’s risk of having a workplace injury? Prior studies examining this issue have yielded mixed findings and have had some important methodological shortcomings. In this presentation, Dr. Nancy Carnide shares new findings from a longitudinal study of Canadian workers looking at the relationship between cannabis use and workplace injury—including workplace use.
Published: March 2022

IWH in the media
Supervisors and people in safety-sensitive jobs using cannabis at work, researchers find
Workers who reported using cannabis before or during a shift – including supervisors and people in safety-sensitive jobs – had jobs and work environments in which detection was less likely, according to the results of a recent study out of Canada.
Published: Safety + Health, April 2021

At Work article
At-work cannabis use linked to work factors, including some not expected: IWH study
What factors differentiate people who use cannabis at work from those who don't? An IWH study finds they all relate to people's job characteristics and environments, including some that are surprising.
Published: February 2021
Project
Project
Ontario Life After Work Injury Study: Cannabis use and long-term recovery and return-to-work outcomes among Ontario injured workers
An IWH study is helping us understand how workers with work-related injuries and illnesses use cannabis and how that use is related to their recovery and return to work.
Status: Ongoing
Project
Project
Opioid-related harms among Ontario workers: a surveillance tool
This project draws on a unique surveillance program and uses data-linkage to capture current trends in opioid-related harms among Ontario injured workers.
Status: Ongoing
Infographic
Infographic
Cannabis use and the Canadian workplace (2020)
From 2018 to 2021, the Institute for Work & Health is conducting a yearly survey of Canadian workers about cannabis. The aim is to understand how the legalization of non-medical cannabis is affecting workers’ cannabis use and beliefs about use. This infographic highlights some of what we learned in our first comparison of pre- and post-legalization findings, based on the first and second surveys.
Published: October 2020

IWH in the media
Is cannabis use on the rise?
Conflicting numbers suggest overall consumption is up, but at-work use unchanged, John Dujay reports on findings of a Institute for Work & Health study led by IWH Associate Scientist Dr. Nancy Carnide.
Published: Canadian HR Reporter, June 2020