Study of Canadian Workers Shows No Link Between Cannabis Use And Workplace Injury

Workers in Canada who have toked up recently don’t appear to have faced any greater risk of a workplace injury than those who abstained, according to a new study out this week, suggesting that cannabis use isn’t necessarily linked to sloppiness on the job.

Researchers from the University of Toronto found “no evidence that cannabis users experienced higher rates of work-related injuries,” and pending other prospective studies, they said that “occupational medicine practitioners should take a risk-based approach to drafting workplace cannabis policies.”

The study, published this month in Occupational Medicine, was based on observations of 136,536 working Canadians. Researchers said that they used “used multiple logistic regression modelling to calculate the odds of experiencing a work-related injury (defined as non-repetitive strain injury) among workers who reported using cannabis more than once during the prior 12 months as compared to non-users,” and then “repeated the analysis among participants working in high injury risk occupational groups only.”

Of the more than 136,500 participants, “2577 (2%) had a work-related injury in the last 12 months,” and among those 2,577, “4% also reported being a cannabis user in the same period.”

“We found no association between past-year cannabis use and work-related injury (odds ratio for work injury among users 0.81, 95% confidence interval 0.66-0.99),” they wrote. “The association was unchanged in the subgroup analysis limited to high injury risk occupational groups.”

They concluded, as quoted by NORML: “To the best of our knowledge, this was the largest population-based cross-sectional study examining the association between past-year cannabis use and work-related injuries. … We found that workers reporting using cannabis more than once in the past year were no more likely to report having experienced a work-related injury over the same time period in a large cohort of the Canadian working population.”

The Canadian government made recreational marijuana use legal in the fall of 2018, although the unregulated weed market has continued to thrive north of the border.

The Study Corroborates Other Findings

The study published in Occupational Medicine follows other research that have dispelled the link between cannabis use and a lack of workplace safety. Earlier this year, researchers from San Diego State University in California and Auburn University found that “after-work cannabis use did not relate to any of the workplace performance dimensions,” which they said “casts doubt on some stereotypes of cannabis users and suggests a need for further methodological and theoretical development in the field of substance use.” 

For marijuana advocates, research like that has been vital in counteracting long-held perceptions about marijuana use, which has led to an end to pot prohibition in states and cities across the country.

In response to this week’s study in Occupational Medicine, NORML’s Deputy Director Paul Armentano took aim at “[s]uspicionless marijuana testing never has been an evidence-based policy.”

“Rather, these discriminatory practices are a holdover from the zeitgeist of the 1980s ‘war on drugs.’ But times have changed; attitudes have changed, and in many places, the marijuana laws have changed. It is time for workplace policies to adapt to this new reality,” Armentano said in a statement.