Heavy share of Canadian pot users admits to driving within 2 hours of toking up: study

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Police say little has changed since cannabis became legal on Oct. 17. Meanwhile, Peterborough's downtown smoking supply store say business is booming – Nov 19, 2018

The legal status of marijuana may have undergone a dramatic change between last year and this year, but there’s one matter that didn’t — the willingness of many pot smokers to admit that they had jumped behind the wheel of a vehicle mere hours after toking up.

That’s one result contained in the 2018 Canadian Cannabis Survey, which looks at cannabis use and related public safety issues, and which was released Monday by the government of Canada.

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Nearly 40 per cent of people who had used cannabis in the past year admitted to having driven within two hours of using the drug.

Of the people who did, 43 per cent reported having done so within the past month, while 27 per cent said they had done it within the past year and 31 per cent more than a year ago.

None of these levels had changed from the survey completed in 2017.

READ MORE: Is alcohol or pot healthier for you? Some Canadians considering switching away from booze

Every one of these people would have acted in contravention of federal guidelines around impairment.

Cannabis impairment can last as long as 24 hours after a person has used it, the federal government said on its website.

How long it takes to wear off can depend on factors such as how much or how often a user has consumed it, or whether the drug was smoked or ingested.

Cannabis harvested at the CannTrust Niagara Greenhouse Facility in Fenwick, Ont., is photographed on June 26, 2018. THE CANADIAN PRESS/Tijana Martin

The government issued its guidelines with a nod to a 1991 academic study that found “carryover effects” from a “moderate social dose of marijuana” could be detected 24 hours later.

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That study saw pilots using an aircraft simulator before using marijuana, as well as 0.25 hours, four hours, eight hours and 24 hours after using the drug.

Researchers found marijuana impairment at every point after smoking.

“The results support our preliminary study and suggest that very complex human/machine performance can be impaired as long as 24 hours after smoking a moderate social dose of marijuana, and that the user may be unaware of the drug’s influence,” the study’s abstract said.

Less significant, but still palpable, was the share of cannabis users who admitted to driving a vehicle after using marijuana in combination with alcohol.

A quarter of respondents said they had driven after combining the two, representing an increase from the 17 per cent share who admitted to doing this in 2017.

“Of those who had driven after using cannabis in combination with alcohol, 33 per cent did so within the past 30 days,” the study said — that number hadn’t changed from last year.

READ MORE: One-third of cannabis buyers still using illicit dealers, according to IPSOS poll

A sizable share of respondents (31 per cent) also admitted to having travelled in a vehicle driven by someone who had recently used cannabis.

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That, however, represented a decrease from the 39 per cent who said so in 2017.

The tendency to travel with drivers who had used cannabis was more common among respondents who had themselves used marijuana within the past 12 months (70 per cent), which was down from the 79 per cent who admitted to this last year.

Bill Blair, Parliamentary Secretary to the Minister of Health, is reflected in a screen as he sits a driving simulator meant to simulate the effects of driving under the influence of Cannabis, during a photo opportunity at Centre for Addiction and Mental Health (CAMH) in Toronto on Wednesday January 24, 2018. THE CANADIAN PRESS/Chris Young

All of these results came in the very same survey in which all but 19 per cent thought cannabis use affects one’s driving.

However, the share of people who felt this way dropped depending on how much cannabis they used themselves.

Of those who reported using cannabis in the past year, 61 per cent said it affects your driving ability.

The study drew responses from 12,958 people aged 16 years and older across all Canadian provinces and territories, in a survey completed between May 15 and July 9.

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Of them, 3,395 respondents indicated that they had used cannabis in the past year for either medical or non-medical purposes.

READ MORE: No spike in cannabis-impaired driving one month after legalization, data shows

Even as several admitted pot smokers said they had driven within hours of using marijuana, however, police across Canada have not reported an uptick in cannabis-impaired driving.

The Canadian Press spoke to police forces and provincial and territorial Crown offices; neither data nor anecdotal impressions suggested that marijuana-impaired driving was growing.

— With files from the Canadian Press

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