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

Fire ban back in effect for Northwest Fire Centre region

Starting May 24, both Category 2 and Category 3 prohibitions will be in place

New Seven Sisters replacement confirmed

Mental health facility will have 25 beds, up from 20 in current facility

Convicted animal abuser to return to B.C. court May 21

Catherine Jessica Adams is facing a breach of probation charge

Healthcare travelling roadshow aims to inspire high school students across B.C

Over 2,000 youth in different rural communities will be visited through this project

Gallery: Project Heavy Duty inspires students into it’s 32nd year

The event is a collaboration between SD91 and industry in and around Vanderhoof, Fraser Lake and Fort St. James

600 new campsites coming to provincial parks and recreation sites across B.C.

Tourism Minister announced half of the new spots to 13 most popular provincial parks

Raptors beat Bucks 105-99 to move within 1 game of NBA Finals

Leonard scores 35 as Toronto takes 3-2 series lead over Milwaukee

Municipalities protest after B.C. declares marijuana crops ‘farm use’

UBCM president seeks answers in letter to John Horgan government

CMHC defends mortgage stress test changes amid calls for loosening rules

Uninsured borrowers must now show they could service their mortgage if rates rose two per cent

Nisga’a Nation tourism industry hits the road

First pilot tour to the Nass Valley is set for this summer with Indigenous Tourism BC

B.C. woman left ‘black and blue’ after being pushed off 40-foot cliff at lake

West Shore RCMP looking for witnesses as investigation continues

Thunderstorms to bring heavy rain, risk of flash floods in the southern Interior

Ten to 30 millimetres of rain to fall over the early weekend

Unbe-leaf-able: Agassiz man finds more than 200 four-leaf clovers in a month

Walt Hardinge has found more than 219 four-or-more leaf clovers this spring alone

Crews fight fire with fire to keep blaze from northern Alberta town

The wildfire now covers some 920 square kilometres

Most Read