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

Columbia River Treaty: ‘It is going to get tough’

B.C. negotiator tells Nelson meeting that talks are cordial, so far

Rockies joust the Knights

Two back-to-back home games this weekend for the Rockies

Fowler’s show films in the Flats

YouTube star Zach Fowler films ‘30 Day Survival Challenge’ YouTube series in Canal Flats

Valley YouTuber sets sights on survival show stardom

Greg Ovens releases 30 Day Survival Challenge videos on his new YouTube channel

Minor Hockey Minute

Silver medals for Rockies’ Senior Girls and Atom Blue teams

VIDEO: ‘Climate emergency’ is Oxford’s 2019 Word of the Year

Other words on the shortlist included ‘extinction,’ ‘climate denial’ and ‘eco-anxiety’

65-million-year-old triceratops makes its debut in Victoria

Dino Lab Inc. is excavating the fossilized remains of a 65-million-year-old dinosaur

B.C. widow suing health authority after ‘untreatable’ superbug killed her husband

New Public Agency Health report puts Canadian death toll at 5,400 in 2018

Changes to B.C. building code address secondary suites, energy efficiency

Housing Minister Selina Robinson says the changes will help create more affordable housing

Security guard at Kamloops music festival gets three years for sexually assaulting concertgoer

Shawn Christopher Gray walked the woman home after she became seperated from her friends, court heard

Algae bloom killing farmed fish on Vancouver Island’s West Coast

DFO says four Cermaq Canada salmon farms affected, fish not infectious

Three cops investigated in connection to ex-Vancouver detective’s sexual misconduct

Fisher was convicted in 2018 after pleading guilty to kissing two young women who were witnesses in a criminal case

Most Read