BOSTON, Mass. — As cannabis becomes a more accepted part of society, a new study finds it’s having a deadly impact on road safety. Researchers from the United States and Canada have discovered that the number of car crash deaths involving cannabis is skyrocketing in recent years. The odds of these deaths involving both cannabis and alcohol is even higher.
Over a 19-year period, the study finds car crash deaths involving cannabis more than doubled across the United States — going from nine percent in 2000 to 21.5 percent in 2018. The percentage of deaths involving both drinking and marijuana rose from 4.8 to 10.3 percent during that time.
The team from Boston Medical Center, Boston University, and the University of Victoria adds that marijuana-related crash victims had a 50-percent higher chance of having alcohol in their systems at the same time. Although advocates for the legalization of cannabis argue that allowing people to use the drug openly will cut down on the use of other substances (like alcohol), researchers say the opposite appears to be happening.
“There has been progress in reducing deaths from alcohol-impaired driving, but our study suggests that cannabis involvement might be undercutting these public health efforts,” says senior author Timothy Naimi, MD, MPH, an adjunct professor at Boston University Schools of Medicine and Public Health and the director of the Canadian Institute of Substance Use Research, in a media release.
Currently, estimates show nearly 40 percent of all crash deaths in America involve alcohol. Around 30 percent of crash deaths involve drinking above the legal limit for drivers. The team found that cannabis use is also a risk factor for alcohol co-involvement, even at levels within the legal limit.
Marijuana tests not painting an accurate picture?
When it comes to impaired driving, researchers say drivers using marijuana don’t just endanger themselves, but their friends as well. The study finds cannabis-involved car accidents are more likely to result in the death of a passenger. These accidents were also more likely to involve people under the age of 35 than those not involving cannabis.
Despite the results, study authors note that testing for marijuana intoxication is still an inexact science. This makes it hard for officials to know how long ago drivers used cannabis before getting on the road and also how much of a role it played in the fatal accident.
“Our testing methods for cannabis remain suboptimal and individuals can test positive for cannabis weeks after they have consumed it,” says lead author Marlene Lira, MPH, an epidemiologist at Boston Medical Center. “However, we can say that fatalities from crashes involving cannabis are more likely to have also involved alcohol, even if we don’t know the exact level of cannabis.”
“The bottom line is that we have a lot of work to do to reduce deaths and harms from impaired driving from alcohol, cannabis, and other substances,” Lira adds.
The study is published in the American Journal of Public Health.