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.

Just Posted

Rohan arul-Pragasam, Chilliwack School District’s interim superintendent, has been appointed superintendent of schools effective June 15, 2021. (Chilliwack School District)
Interim position becomes permanent for Rohan Arul-pragasam at Chilliwack School District

Arul-pragasam said he was ‘humbled to continue as a steward’ in new role as superintendent of schools

PlanCultus was adopted in 2017 as a guiding document for Cultus Lake Park. (Cultus Lake Park Board)
More affordable housing options could be coming to Cultus Lake Park

Online survey opened on June 14 to gauge opinion on plaza redevelopment eyed for Village Centre

The Abbotsford International Airshow is back for 2021 with the ‘SkyDrive’ concept.
Abbotsford International Airshow returns for 2021 with ‘SkyDrive’

New format features a drive-in movie type experience, show set for Aug. 6 to 8

A young couple walks through the Othello Tunnels just outside of Hope. (Jessica Peters/Black Press)
Hope’s Othello Tunnels fully open to the public

Geological testing proved the area safe enough to open for the first time in more than a year

Raeya Evie Duncan was the 100th baby born at Chilliwack General Hospital for the month of May. She is seen here with her parents Alysha Williams and Andrew Duncan on June 12, 2021. (Jenna Hauck/ Chilliwack Progress)
Baby boom in Chilliwack as record number of infants born at CGH in May

‘COVID babies are coming out,’ says dad of 100th baby born at Chilliwack General Hospital last month

Maxwell Johnson is seen in Bella Bella, B.C., in an undated photo. The Indigenous man from British Columbia has filed complaints with the B.C. Human Rights Tribunal and the Canadian Human Rights Commission after he and his granddaughter were handcuffed when they tried to open a bank account. THE CANADIAN PRESS/HO-Heiltsuk Nation, Damien Gillis, *MANDATORY CREDIT*
VIDEO: Chiefs join human rights case of Indigenous man handcuffed by police in B.C. bank

Maxwell Johnson said he wants change, not just words, from Vancouver police

Tk’emlups te Secwepemc Chief Rosanne Casimir stands outside the former Kamloops Indian Residential School after speaking to reporters, in Kamloops, B.C., on Friday, June 4, 2021.THE CANADIAN PRESS/Darryl Dyck
Kamloops chief says more unmarked graves will be found across Canada

Chief Rosanne Casimir told a virtual news conference the nation expects to release a report at the end of June

A woman wears a vaccinated sticker after receiving a COVID-19 vaccine at a vaccination clinic run by Vancouver Coastal Health, in Richmond, B.C., Saturday, April 10, 2021. THE CANADIAN PRESS/Jonathan Hayward
B.C. ranks among highest in world in COVID-19 first-dose shots: health officials

More than 76% of eligible people have received their 1st shot

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

A screenshot of the First Peoples Cultural Councils First Peoples’ Map. (First Peoples Cultural Council)
Online resource blends B.C.-Alberta’s Indigenous languages, art and culture

Advisor says initiative supports the urgent need to preserve Indigenous languages

An artists conception of the new terminal building at the Pitt Meadows Regional Airport.
Air travel taking off in B.C., but lack of traffic controllers a sky-high concern

There will be demand for more air traffic controllers: Miller

Canadian Armed Forces experts are on their way to North Vancouver after a local homeowner expressed worry about a military artifact he recently purchased. (Twitter DNV Fire and Rescue)
Military called in to deal with antique ‘shell’ at North Vancouver home

‘The person somehow purchased a bombshell innocently believing it was an out-of-commission military artifact’

Amy Kobelt and Tony Cruz have set their wedding date for February, hoping that more COVID-19 restrictions will have lifted. (The Macleans)
B.C. couples ‘gambling’ on whether COVID rules will let them dance at their wedding

Amy Kobelt and Tony Cruz pushed back their wedding in hopes of being able to celebrate it without the constraints of COVID-19

Most Read