A new study looking at high school students riding in cars with drivers who have been consuming alcohol or marijuana has found results that its lead author calls troubling.

The University of Waterloo study surveyed students from Grade 9 to Grade 12.

It found that 35 per cent of respondents said they had been in cars where drivers had consumed at least one alcohol drink in the past hour, while nearly 20 per cent said they had been a car with a driver who had used marijuana in the past two hours.

“These numbers are concerning because Canadian youth are at higher risk of death from traffic injuries than any other age group,” Leia Minaker, the study’s lead author, said in a news release.

With the survey narrowed down to Grade 11 and Grade 12 students, 9.4 per cent responded that they had driven after using marijuana, while about nine per cent said they had driven an hour or less after drinking alcohol.

Minaker says that with marijuana legalization looming, the federal government should ensure marijuana is kept away from kids.