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.

Just Posted

Smoke-free summer a boon for West Kootenay tourism

Tourism centres seeing numbers up

Saving lives on grocery list for Castlegar responders on Wednesday

Crews attended local supermarkets three times during the day

Black Press Kootenay Career Fair underway in Cranbrook

Today, Thursday, August 22, around 40 employers will be waiting to meet potential new employees

National trail group decries province’s plans for West Kootenay trail

Converting trail back to motorized use will harm its international reputation, says official

Cannings to pedal through South Okanagan — West Kootenay riding

MP leaves from Nakusp on Aug. 23 and ends in Kaleden on Aug. 29.

Black Press Career Fair underway in Cranbrook at Days Inn

Opportunities abound for employers and job seekers

B.C. music teacher accused of sexual misconduct involving girls

Police believe other victims could be out there after the arrest of Lamar Victor Alviar

B.C. family stranded in Croatia desperate to come home

Funds being raised to bring back mom and two children

B.C. man tells judge he attempted suicide a month before daughters’ murders

Andrew Berry takes stand in his defense for December 2017 deaths of young daughters

‘Plenty of time for a deal’: Teachers’ union expects kids back in school on Sept. 3

BCTF says class size, composition at the heart of the issue

Province funds new shuttle buses for 13 B.C. senior centres

Activity, socializing helps maintain health, Adrian Dix says

Thermal imaging cameras eye Salish Sea in hopes of better detecting whales

Cameras installed at BC Ferries’ terminal on Galiano Island, and off southern Gulf Islands

BREAKING: Province approves Surrey police force

Minister of Public Safety Mike Farnworth green-lights city’s municipal police force

B.C. father tells judge he did not kill his young daughters

Andrew Berry pleaded not guilty to the December 2017 deaths

Most Read