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

What’s Up: Things to see and do on Family Day

There’s plenty of fun to be had across the West Kootenay this coming long weekend!

Province announces $23 million for upgrades at Kootenay Boundary Regional Hospital

West Kootenay-Boundary Regional Hospital District Board has yet to review the provincial proposal

Call a foul on cancer with the Pink Whistle Campaign

Local basketball referees are raising money for cancer research

UPDATE: Two-car accident closes Highway 3A at Thrums

Road expected to open for single-lane alternating traffic at 2 p.m.

Trail Curling Club set for BC senior championships

Volunteers step up for BC Senior Curling championships at Trail Curling Club

B.C. students win Great Waters Challenge video contest

Video, mural and song about saving the salmon claims the top prize

Disgraced ex-Congressman Anthony Weiner released from prison

He was convicted of having illicit online contact with a 15-year-old North Carolina girl in 2017

B.C. communities push back against climate change damages campaign

Activists copying California case that was tossed out of court

B.C. VIEWS: Power politics wins over rational energy policy

B.C Hydro continues to face interference on rates

PR firm suspends contract with former B.C. premier amid groping accusation

Edelman says in a statement that Campbell has served as a special adviser to the firm since last July

James says B.C. budget puts priorities on NDP’s poverty, environment plans

She said she expected the government’s poverty reduction and climate change strategies to be priorities in the budget

PHOTOS: Day 1 of the 2019 Canada Winter Games in Red Deer

Games kicked off in Red Deer this week

Most Read