Study: Past-Year Marijuana Use Not Associated with Elevated Risk of Workplace Injury

Drug Testing

Those with a history of cannabis use over the past year are no more likely than non-users to experience an injury at work, according to data published in the journal Occupational Medicine.

A team of investigators affiliated with the University of Toronto, Department of Occupational Medicine, assessed the relationship between past-year cannabis use and work-related injuries in a population-based sample of over 136,500 Canadian workers.

Researchers identified “no association between past-year cannabis use and work-related injury” for employees in any occupation, including those who worked in high injury risk occupations. By contrast, being male and being under 39 years of age was positively associated with having a higher risk of workplace injury.

Authors concluded: “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.”

Their conclusions are similar to those of other studies — such as those here, here, here, and here — finding that adults who consume cannabis in their off-hours are no more likely to suffer injuries at work than are those employees who abstain from the substance.

Commenting on the study’s findings, NORML’s Deputy Director Paul Armentano said: “Suspicionless marijuana testing in the workplace is not now, nor has it ever 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 and to cease punishing employees for activities they engage in during their off-hours that pose no workplace safety threat.”

In recent months, lawmakers in several municipalities – including New York City, Richmond, Virginia, and Washington, DC – have enacted legislation limiting the use of marijuana-specific pre-employment drug screening.

Both Maine and Nevada have enacted state-specific legislation barring certain employers from refusing to hire a worker solely because he or she tested positive for cannabis on a pre-employment drug screen.

The abstract of the study, “Cannabis use and work-related injuries: a cross-sectional analysis,” is online here. Additional information is available from the NORML Fact Sheet, “Marijuana Legalization and Impact on the Workplace.”