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

Malicious Monster Truck Tour returns to Northwest

Crowds gathered at the airport for show

Terrace SAR rescues shopping carts in Skeena River

Many have yet to be retrieved due to high water level

Driver crashes into tree down Skeenaview embankment

A driver received minor injuries after crashing into a tree at the… Continue reading

Terrace Friendship Centre awarded $200,000 for MMIWG project

Project brings together Northwest communities to create long-term change, says executive director

Northern B.C.’s Ridley coal terminal sold, Canada divests, First Nations to own portion

Ten per cent of shares transferred to the Lax Kw’alaams Band and the Metlakatla First Nation

‘Bad choices make good stories’: Margaret Trudeau brings her show to Just for Laughs

Trudeau says over the decades she has been suicidal, manic, depressed

ICBC insurance renewals get more complicated this year

Crash history, driver risk prompt more reporting requirements

Diversity a Canadian strength, Trudeau says of Trump tweets at congresswomen

Trudeau avoided using Trump’s name when he was asked about the president’s Twitter comments

B.C. couple bring son home from Nigeria after long adoption delay

Kim and Clark Moran of Abbotsford spent almost a year waiting to finalize adoption of Ayo, 3

Health Canada revokes licences of B.C.-based pot producer Agrima Botanicals

The agency said it notified the company of a suspension in November due to non-compliance with regulations

Deals, protests during Amazon Prime Day

The Seattle-based e-commerce behemoth says it is offering more than a million deals

Canadian national softball team wins second straight Canada Cup

Team Canada defeats Texas-based Scrapyard International in gold-medal game Sunday in Surrey

June sees drop in home sales, prices for real estate across B.C.: report

Sales dropped by 11.8%, while prices fell by 4%

Most Read