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

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

A car rally is set to meet at Abbotsford’s Rotary Stadium on Saturday to protest the issues related to farmers in India. (Instagram photo)
Pair of farmers’ protests occurring in Abbotsford this weekend

Car and truck rally set for Saturday, tractor rally event scheduled for Sunday

Abbotsford’s Tradex has been transformed into a volleyball and basketball facility with Open Court. (Instagram photo)
Abbotsford’s Tradex transforms into sports facility

Open Court program hosting volleyball and basketball teams for practices and possibly games

Abbotsford’s Skully White (left), who donated his kidney in December, has started a campaign to find other recipients and donors. The first candidate is retired police officer Gavin Quon. White owns and operates a hotdog stand, Lullys Food Experience, out of the Abbotsford Canadian Tire parking lot. (Facebook photo)
Abbotsford hotdog-stand owner starts campaign to find kidney donors and recipients

Skully White donated his kidney to customer Tim Hiscock in December

COVID-19. (Image courtesy CDC)
18 school exposures in Abbotsford since Jan. 6

21 exposures since the the holiday break

Dallas Lajimodiere is wanted by the Abbotsford Police Department.
Man wanted by Abbotsford Police domestic violence unit

Dallas Lajimodiere has three arrest warrants, including for assault with a weapon

Businesses continue to struggle under COVID-19 restrictions as the pandemic reaches the one-year mark. (B.C. government)
Another 564 COVID-19 cases, mass vaccine plan coming Friday

15 more deaths, community cluster declared in Williams Lake

A specialized RCMP team is investigating a suspicious trailer, which might have connections to the illicit drug trade, found abandoned outside a Cache Creek motel. (Photo credit: <em>Journal</em> files)
Police probe U-Haul trailer linked to illicit drugs left outside Cache Creek motel

Hazardous materials found inside believed to be consistent with the production of illicit drugs

Premier John Horgan leaves the podium following his first press conference of the year as he comments on various questions from the media in the Press Gallery at B.C. Legislature in Victoria, B.C., on Monday, January 13, 2020. THE CANADIAN PRESS/Chad Hipolito
Interprovincial travel restrictions a no-go, Horgan says after reviewing legal options

The B.C. NDP government sought legal advice as concerns of travel continue

Gem Lake Top, at Big White Ski Resort, seen at Jan. 8. (Big White Ski Resort)
Big White cancels $7.3M in lift tickets, accommodations due to COVID-19 orders

Since November, the ski resort has been forced to make several changes

Darlene Curylo scratched a $3M ticket, BCLC’s largest ever scratch and win prize. (BCLC)
Kelowna woman in shock after winning BCLC’s largest-ever instant-ticket prize

Darlene Curylo couldn’t believe her eyes when she saw the amount of money she’d won from a scratch ticket

While each person has different reasons for becoming homeless, a UBCO study shows they learn through their interactions with different services to perform ‘as homeless’ based on the expectations of service providers. (Contributed)
Kelowna homeless forced to ‘perform’ for resources, says UBCO study

One participant in the study said ‘It is about looking homeless, but not too homeless’

Gov. Gen. Julie Payette takes the royal salute from the Guard of Honour as she makes her way deliver the the throne speech, Wednesday, September 23, 2020 in Ottawa. THE CANADIAN PRESS/Fred Chartrand
Gov. Gen. Julie Payette resigns, apologizes for ‘tensions’ at Rideau Hall

Payette, who is the Queen’s representative in Canada, has been the governor general since 2017

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Grounded WestJet Boeing 737 Max aircraft are shown at the airline’s facilities in Calgary, Alta., Tuesday, May 7, 2019. WestJet will operate the first commercial Boeing 737 Max flight in Canada today since the aircraft was grounded in 2019 following two deadly crashes. THE CANADIAN PRESS/Jeff McIntosh
Passengers unfazed as WestJet returns Boeing 737 Max to service on Vancouver flight

After a lengthy review process, Transport Canada cleared the plane to return to Canadian airspace

Most Read