Cannabis plants in BlissCo, a manufacturing facility in Langley, B.C. (Ashley Wadhwani/Black Press Media)

Here’s a first look at Canada’s sewage tests for cannabis use

The first-of-its-kind tests involve gauging traces of THC, the active ingredient in marijuana, at 15 wastewater treatment plants in Canada

Canadians eat or smoke anywhere between 400 to 1,600 tonnes of cannabis per year, according to a few months of sewage samples examined for the federal government.

The wide-ranging estimate, released by Statistics Canada on Thursday, is the first look at cannabis use through a new technique called wastewater-based epidemiology. The tests involve gauging traces of THC, the active ingredient in marijuana, at 15 wastewater treatment plants in five different cities, including Vancouver.

After cannabis is metabolized in the body, traces of THC are left behind in human waste. Scientists collected wastewater on the second week of each month from March to August this year – before cannabis was legalized in Canada on Oct. 17.

As expected, more cannabis is consumed in Canada’s larger cities. Montreal had the highest rate of consumption at roughly 1,922 grams per week, according to the analysis. Toronto had the second highest at 1,257 grams, followed by Vancouver with 721 grams.

READ MORE: Canadian trial to compare cannabis and fentanyl in relieving chronic pain

READ MORE: B.C. woman looks to reduce stigma surrounding weed-smoking moms

The sample tests were meant to overcome under-reporting by cannabis users, often caused by the stigma of the drug and reluctance for people to admit their illegal purchases.

“One consequence of under-reporting is that the size of the black market for cannabis will be similarly underestimated,” the report reads.

“As a result, without a direct measurement of cannabis consumption, the reduction of the black market for cannabis – one of the objectives of the legalization of non-medical cannabis – will be hard to track.”

READ MORE: 10 things still illegal in the new age of recreational cannabis

While the estimates offer a first look at the truth behind cannabis use, Statistics Canada said the numbers are experimental and that more information is needed, such as how much of the drug is excreted, its potency and the way the drug is consumed. Other factors to consider include different chemicals in the various treatment plants themselves.

“In the case of cannabis, there are many different kinds of products, with different THC potency levels, and this adds further complexity to estimation methods,” the report reads.

Sampling will continue until the spring of 2019.

WATCH: Inside a B.C.-based marijuana production facility


@ashwadhwani
ashley.wadhwani@bpdigital.ca

Like us on Facebook and follow us on Twitter.

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

Just Posted

Pitt Meadows losing one-third of skilled paid-on-call firefighters a year

Experienced paid-on-call firefighters being hired full-time in other communities

Over 600 Pitt Meadows citizens sign petition to protest North Lougheed development

Petition requests more environmental information before development decisions carried out

Pass slow and wide, please

Maple Ridge mom pleads with drivers to show care after daughter falls from spooked pony on 132nd Ave

Mounties collar suspect after shots ring out in Maple Ridge

Weekend incident on 227th Street leads police to Surrey for one arrest and gathering of evidence

Facing changes together: Your community, your journalists

Thanks for helping The News to continue its mission to provide trusted local news

B.C. drive-in theatre appeals COVID-19 concession rules, 50-car limit

With 50 cars and the removal of concession sales, drive-in owner says theatre might have to close

COVID-19: B.C. grants aim to stabilize sexual assault recovery programs

$10 million fund not yet ready to take applications

B.C. mom’s drug-pricing petition on behalf of son garners thousands of signatures

Petition geared to gaining access to new medicines drew support of Chilliwack-Hope MP Mark Strahl

Gabriel Klein’s sentencing delayed until September

Man convicted of killing Abbotsford high school student Letisha Reimer was set for June

‘Paralyzed by fear’: B.C. woman details anxiety, grief at Italian relief hospital

Sheila Vicic spent two months in Italy as the country grappled with COVID-19

Dr. Bonnie Henry given new name in B.C. First Nation ceremony: ‘one who is calm among us’

The provincial health officer was honoured in a May 22 ceremony at elementary school in Hazelton

CAMH survey looks at binge-drinking, financial anxiety during COVID

Alcohol may be used as a coping mechanism for those whose careers may have been sidelined due to the pandemic

Most Read