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

Home fire reported near Sunset Avenue

Reporter is headed to the scene. Updates to come.

Petition to stop new cell tower too close to Kelowna homes

An online petition was started to stop cell tower construction near Ellison Elementary School

Local Kelowna project tabs restaurant workers for industry fundraiser

The 2nd Hungry Games invites fundraises for local charities

Okanagan-Shuswap weather: Clear skies and pushing 20 C

Environement Canada forcasts a sunny and warm Easter weekend

Peeling away: OK strip clubs disappearing

Hear from Penticton’s only strip club owner about their success in a dying industry

Parliament Hill 4-20 organizers predict record crowd after legalization

A celebration? Yes, but organizers say concerns remain about the government’s decisions on legalization rollout

Motorcycle crash on Highway 97 in Penticton sends driver to hospital

No other vehicle was involved in the incident, the condition of the driver is unknown

Egg hunts take over Vernon

Among the hunts include the 14 annual Schnare’s Massive Egg Hunt.

Seven tips to travel safely this Easter long weekend

An average of three people are killed, and hundreds more injured, each Easter long weekend in B.C.

Parents say Austrian climber missing in Banff National Park ‘lived his dream’

David Lama, Hansjorg Auer and American climber Jess Roskelley have been missing since Wednesday

Six months after legalization, high prices and supply issues boost illicit pot market

It has been six months since Canada became the first industrialized country to legalize recreational cannabis

Seattle’s 4-20 ‘protestival’ enjoys tolerance, some support – and B.C. could do the same

Seattle’s Hempfest a large-scale occasions with vendors, prominent musical acts and thousands of attendees

B.C. mountain biker sent home from hospital twice, despite broken vertebrae

Released in Maple Ridge to go home with three fractured vertebrae

Deck collapses in Langley during celebration, multiple people injured

Emergency responders rushed to the Langley home

Most Read