The Ministry of Public Safety announced a three-year study into cannabis and driving, three months before marijuana is legalized. File photo

The Ministry of Public Safety announced a three-year study into cannabis and driving, three months before marijuana is legalized. File photo

In a haze: Cannabis impairment still unclear for drivers in B.C.

Feds launch three-year study with mere months to go before legalization across Canada

In less than three months marijuana will officially be legalized across Canada and Oct. 17 will be a big day for law enforcement, as research is still underway to determine how the practical implications of the new legislation will be rolled out.

Earlier this month the federal Ministry of Public Safety announced it is launching a three-year study into the effects of cannabis on drivers. The nearly million dollar study will place drivers aged 19 to 45 in simulated driving scenarios to see how different levels of THC – the psychoactive ingredient in cannabis – affects their driving ability.

Why the government decided to look into this now and not earlier remains a mystery (the Ministry has not replied to multiple requests for comment). What is even more unclear is how drivers’ sobriety will be determined in the fall.

Scott MacDonald is a health sciences professor at the University of Victoria who recently retired as assistant director at the Canadian Institute of Substance Use Research (CISUR).

ALSO READ: B.C. ‘will be ready’ for marijuana legalization

He explained that law enforcement officers will use an oral test to check the THC level in a driver’s saliva. A blood test would later be administered to find the exact levels of THC in the individual’s system.

Bill C-46 is aiming to change the criminal code regarding impaired driving, and sets two threshold levels for THC in the bloodstream, with the first at two nanograms, the next at five ng. Theoretically, the higher the levels, the higher the impairment – and potentially the higher the fine.

The problem, MacDonald said, is how THC is metabolized by the body.

“THC binds to the fat cells of the body, so they’re kind of released slowly over time,” he said. “You’re not really high, but it can go back into your blood and remain in your system for quite some time.”

He noted that this is very different from alcohol, which is eliminated from the body at a very constant rate.

Heavy marijuana users – those who smoke every day – can build up quite a tolerance. They can hold THC in their systems up to five days after they smoked, reaching levels of at least two nanograms in an oral test even though, at that point, they would not present any symptoms of intoxication.

“What happens when people have cannabis is their THC levels rise very rapidly, and could [increase] to over 100 nanograms in the first 15 minutes,” MacDonald said. “Then, they decline very rapidly by 90 per cent in the first hour, then kind of level off. It’s when the THC has levelled off that it’s very difficult to pick a cut off point that would be accurate.”

MacDonald believes the numbers to be used to test if someone is high, are too low.

“This is a step above zero-tolerance; they’re not impaired-based laws like we have with alcohol.”

Marijuana edibles bring an even greater challenge, he said, since ingested cannabis not only takes longer to kick in – averaging about an hour – but also creates a completely different chemical reaction.

“It goes directly to stomach and liver and when it’s metabolized, it creates a new compound called hydroxy-THC,” MacDonald said. “It’s more potent than THC itself, but no one’s been able to accurately measure hydroxy-THC for an impairment level.”

ALSO READ: Marijuana growing rules aim to protect B.C. farmland

Law enforcement officers will received an approved screening device for oral tests soon, though at this point they don’t know which brand it will be, or when they will receive them.

Sgt. Shannon Perkins works with the traffic section of the Victoria Police Department. She said any such device will only be a tool to go along with their standard field sobriety test (SFST), an impairment check that requires the driver to walk heel-to-toe in a straight line then turn, during which the officer observes their eyes.

In response to MacDonald’s concerns over potential problems with low THC thresholds, Perkins said the specific numbers aren’t the point.

“We need to not get so hung up on levels or the presence of drugs,” Perkins said. “The device leads us to levels, which goes into a larger part of an entire investigation.”

She warned, however, that regardless of how low an individual’s levels may be, different people will react differently to drugs and should simply not drive if they’ve had cannabis.

“If it’s still in their system, how do we know it won’t affect their driving?” she said. “We’d love to tell the public how much they can have, but because we can’t provide that, they need to take responsibility … if the user doesn’t bear responsibility, should society?”

The B.C. Association of Chiefs of Police have instructed police departments to have 30 per cent of their front line officers trained in SFST by October in anticipation of higher instances impaired driving.

“It’s a state of change,” Perkins said. “Police agencies don’t have all the answers yet. There will be case law arguments and changes, and that’s how it goes.”

nicole.crescenzi@vicnews.com

Like us on Facebook and follow us on Twitter
and Instagram

cannabisLegalized Marijuana

Get local stories you won't find anywhere else right to your inbox.
Sign up here

 

Driving high on marijuana will still be illegal when pot becomes legalized, but the impairment enforcement rules still need fine tuning. iStock photo

Driving high on marijuana will still be illegal when pot becomes legalized, but the impairment enforcement rules still need fine tuning. iStock photo

Just Posted

Traffic was tied up at the intersection of Scott and Old Yale Roads in North Surrey on Tuesday afternoon, after a semi truck hauling a load of pipes flipped while making a turn. (Shane MacKichan photos)
VIDEO: Semi hauling load of pipes flips in North Surrey intersection

Traffic near Scott and Old Yale Roads tied up by Tuesday afternoon incident

Sheila Malcolmson, B.C.’s minister of mental health and addictions (Screen shot)
Minister of mental health tells Surrey audience COVID-19 ‘has made everything worse’

More than 23,000 people in B.C. are receiving medication to treat opioid addiction

Farmers raise slogans during a protest on a highway at the Delhi-Haryana state border, India, Thursday, Dec. 3, 2020. Tens of thousands of farmers descended upon the borders of New Delhi to protest new farming laws that they say will open them to corporate exploitation. THE CANADIAN PRESS/AP-Manish Swarup
Delta council stands in solidarity with protesting Indian farmers

Farmers have been protesting for months new laws they say leave them open to corporate exploitation

Shana Harris-Morris was killed Feb. 4. (GoFundMe photo)
IHIT says 22-year-old killed in Surrey shooting was ‘unintended victim’

Shana Harris’ family makes appeal for more information

RCMP. (Phil McLachlan - Black Press Media file)
Man charged after pushing pregnant woman to the ground in Surrey, police say

Surrey RCMP say it appeared to be an ‘unprovoked assault’

Restaurant patrons enjoy the weather on a patio in Vancouver, B.C., Monday, April 5, 2021. The province has restricted indoor dining at all restaurants in B.C. due to a spike in COVID-19 numbers. THE CANADIAN PRESS/Jonathan Hayward
B.C.’s COVID-19 indoor dining, drinking ban extending into May

Restaurant association says patio rules to be clarified

In a 2019 photograph, Yin Yin Din held a picture of her brother Kyaw Naing Din, 54, and her late father Hla Din who passed away in 2014, during a trip to Victoria. (The News files)
Family of B.C. man killed by cop appeals to Attorney General for help

The Din family want B.C. Attorney General David Eby to forward their case to Crown

B.C. Premier John Horgan speaks at the B.C. legislature. (B.C. government)
Tougher COVID-19 restrictions in B.C., including travel, still ‘on the table’: Horgan

John Horgan says travel restrictions will be discussed Wednesday by the provincial cabinet

Protesters occupied a road leading to Fairy Creek Watershed near Port Renfrew. (Submitted photo)
B.C. First Nation says logging activist interference not welcome at Fairy Creek

Vancouver Island’s Pacheedaht concerned about increasing polarization over forestry activities

Flow Academy is not accepting membership applications from anybody who has received a dose of the vaccine, according to a password-protected membership application form. (Submitted image)
B.C. martial arts gym refusing patrons who have been vaccinated, wear masks

Interior Health has already issued a ticket to Flow Academy for non-compliance with public health orders

Of 46 arrests made between March 16 and 19 at Metrotown mall in Burnaby, 27 suspected shoplifters are now facing charges. (Twitter/Burnaby RCMP)
RCMP arrest 46 people in 4 days during Metrotown shoplifting crackdown

$4,800 in stolen merchandise was recovered and returned to businesses inside of the mall

Maple Ridge's Doug Ubell caught some photographs recently that he was anxious to share, one taken while on the Trans-Canada Trail looking southwest towards the Pitt River Bridge, and another from on Golden Ears Bridge. (Special to The News)
Traffic on Golden Ears Bridge returning to pre-pandemic levels

Commuters from Greater Vancouver still driving more, taking transit less

Kao Macaulay has been charged in relation to a home break-in on March 30 in Abbotsford in which five kittens were stolen. (Facebook photo)
‘Prolific offender’ charged with theft of 5 newborn kittens in Abbotsford

Kao Macaulay, 23, is accused of breaking into home on March 30

Facebook screenshot of the sea lion on Holberg Road. (Greg Clarke Facebook video)
VIDEO: Sea lion randomly spotted on remote B.C. logging road

Greg Clarke was driving home on the Holberg Road April 12, when he saw a large sea lion.

Most Read