Research Suggests Cannabis Use Won’t Elevate Risk of Workplace Injury

Joyce Chenzi Zhang and a research team from the department of occupational medication at the University of Toronto recently examined the relationship between work-related injury and cannabis use in a study that took a cross-sectional analysis of a Canadian Community Health Survey of working persons. Of the 136,536 working participants, there were around 2,577 individuals who had work-related injuries within the past 12 months. Of those who experienced a work-related injury, only 4% (±103 people) reported being cannabis users in the same period. The study concluded by stating that they found no evidence that cannabis consumers “experienced higher rates of work-related injuries”. 

Common Causes of Occupational Injury

What are the most common causes of work-related injuries? According to statistics, the top three reasons for injuries in the workplace are due to the following: 

1. Overexertion/Muscle Strain: With the injury rate at 28.2 per 10,000 full-time workers
2. Slips, Trips, and Falls: With the injury rate at 23.9 per 10,000 full-time workers
3. Being Struck by an Object or Equipment: With the injury rate at 23.5 per 10,000 full-time workers

Cannabis Use and the Risk of Workplace Injuries

Cannabis consumption is becoming increasingly acceptable and it’s not uncommon for workers to test positive for THC on company mandated drug tests. But despite gaining acceptance, legalization, and decriminalization, testing positive for THC can lead to a refusal to hire as well as disciplinary actions or even termination depending on company policies. 

The primary reason for a company’s intolerance of employee cannabis consumption is the concern of safety, especially since there are many claims and assumptions that cannabis use is linked to increased workplace injuries. Luckily, Zhang and her team have disproven this in their recent study. And even better, there are also other supporting studies that have also found no correlation between cannabis and increased workplace injury. 

Supporting Studies

Researcher James Price conducted a study that compared urine tests positive for cannabis against work-place accidents and found no difference in workplace accidents between those who tested positive for THC and those who didn’t. Researchers Biasutti, Leffers, and Callaghan concluded their study by stating that there is insufficient evidence to support that cannabis users were at increased risks of occupational injury and they found that most claims of cannabis use leading to injury were based on significant biases. Another study conducted compared cannabis users who have been consuming for more than 11 years, between 1 and 10 years as well as those who have never consumed cannabis at all. The team found that cannabis use for any amount of time was insignificant and found that working multiple jobs or longer hours, as well as labor-intensive occupations, account for the biggest risk factors of occupational injury.

Zhang and the teams’ research was published in the Society of Occupational Medicine on the 27th of October 2020, was actually predicted by the researchers to display evidence that cannabis does indeed lead to increased work-place injury, but obviously, that is not what the evidence displayed. Their study took normal risk factors into account such as gender and age but ultimately found that cannabis consumers experienced work-place injuries at the same rate as those who don’t consume cannabis.  

Ultimately, Employers Want to Play it Safe

Employers often prohibit cannabis consumption because of the potential risks it may pose to the employee themselves or others. This concern is based on the fact that THC is intoxicating and can potentially impact reaction time, perception of time, clear thinking, and problem-solving. Employers are particularly concerned about consuming cannabis if the work involves operating machinery and driving due to the commonly accepted notions of cannabis impairing attentiveness, motor coordination as well as the perception of speed- which has also been refuted in studies. 

Tetrahydrocannabinol (THC) and Cannabidiol (CBD) are both psychoactive compounds found in the cannabis plant which means it may be likely that they impact functioning if consumed at work. However, most individuals that consume cannabis outside of work usually do so off-hours without issue. Be that likelihood as it may, the research points to no correlation between cannabis use and increased work-place injury.