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.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Suspect in North Delta home invasion facing attempt murder charge

Blaine Robert Jackson, 37, of no fixed address, faces six charges in relation to this incident

Rooftop hatchlings ‘a nice addition’ to White Rock RCMP operations

Pair of seagull chicks hatched in ‘fenced playground’ on July 2

North Delta yoga studio’s Fridays at the Farm to benefit local animal sanctuary

The outdoor four-class series will benefit Perfect Pastures Animal Sanctuary in Ladner

‘Justice for Mona’ rally planned for Surrey

Security camera footage shows Mona Wang being dragged, stepped on during RCMP wellness check at UBCO

Sources receives $70K from SurreyCares

Funds will help with warehouse space for food programs in Surrey, White Rock, Langley

B.C. sees 25 new COVID-19 cases, community exposure tracked

One death, outbreaks remain in two long-term care facilities

VIDEO: Vancouver Island cat missing 18 months reunited with family

Blue the cat found at Victoria museum 17 kilometres from home

VIDEO: Alberta man rescues baby eagle believed to be drowning in East Kootenay lake

Brett Bacon was boating on a lake in Windermere when he spotted the baby eagle struggling in the water

Police nab three impaired drivers in one night in Maple Ridge

Ridge Meadows RCMP served 80 impaired driving infractions in June

Conservationists raise concerns over state of care for grizzly cubs transferred to B.C. zoo

‘Let them be assessed now before their fate is sealed,’ urges B.C. conservationist Barb Murray

B.C.’s COVID-19 job recovery led by tourism, finance minister says

Okanagan a bright spot for in-province visitor economy

National Kitten Day aka the ‘purrfect’ day to foster a new friend

July 10 marks National Kitten Day, a special day to celebrate all things kittens

Lower Mainland YouTubers claim to be Kelowna display toilet ‘poopers’

RCMP can not speak to legitimacy of video, will be investigating

Haida matriarchs occupy ancient villages as fishing lodges reopen to visitors

‘Daughters of the rivers’ say occupation follows two fishing lodges reopening without Haida consent

Most Read