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

Pilot program to help Cowichan seniors age in place

Seniors Foundation partnering with B.C. tech company Hibou

Green leader Elizabeth May makes campaign stop in Duncan

Says she’s confident voters looking for Green alternative

Coming up in Cowichan: Special service at Cobble Hill cenotaph Saturday

Malahat Legion hosting special service at Cobble Hill cenotaph The Royal Canadian… Continue reading

Zivanai Masango opens new performance space at Little Zimbabwe Farm in Cowichan

Exciting African singer/ songwriter is the first to play the new studio at Cowichan Lake Road farm

Carter family continues tradition of making musical memories in Cowichan

On Saturday the Alf Carter Band, will be providing the entertainment at the Eagles Hall in Duncan.

VIDEO: First all-female spacewalk team makes history

NASA astronauts Christina Koch and Jessica Meir did work on International Space Station’s power grid

Zantac, the over-the-counter heartburn drug, pulled in Canada, U.S.

Health Canada also investigates possible carcinogen in some ranitidine drugs

B.C. public safety minister says cannabis edibles not in stores til January

Mike Farnworth says he wants regional issues considered when it comes to licensing

Greta Thunberg calls for climate action in Alberta, but doesn’t talk oilsands

Swedish teen was met with some oil and gas industry supporters who came in a truck convoy

Scheer denies spreading ‘misinformation’ in predicting unannounced Liberal taxes

Conservative leader had claimed that a potential NDP-Liberal coalition could lead to a hike in GST

Council asks to limit cruise ship visits to Victoria harbour

Mayor says motion is not meant to curtail current visits or limit local cruise industry expansion

Chilliwack man pleads guilty in crash that killed pregnant woman

Frank Tessman charged under Motor Vehicle Act for accident that killed Kelowna school teacher

Kawhi Leonard, former Toronto Raptor, welcomed back to Vancouver at pre-season game

Fans go wild at pre-season game between L.A. Clippers and Dallas Mavericks at Rogers Arena

Greens and NDP go head to head on West Coast; Scheer takes fight to Bernier

Trudeau turns focus to key ridings outside Toronto after two days in Quebec

Most Read