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

Vanderhoof eligible for up to $6M in provincial infrastructure funding

The Northern Capital and Planning Grant will go to four regional districts and 22 municipalities

Province announces $100-million grant funding for Northwest communities

The Northern Capital and Planning Grant will go to four regional districts and 22 municipalities

Prince Rupert Gas Transmission project searches for partners

TransCanada is renewing permits for its natural gas pipeline project to North Coast.

Over 2,000 people used the pool in the first 2-weeks

Lifeguard training course needs a minimum of six people to register before Feb. 21

Coastal GasLink stops work to investigate archaeological find

OGC archaeologists are en route to the Houston-area site where Unist’ot’en report finding stone tools

Trudeau’s principal secretary, Gerald Butts, resigns amid SNC-Lavalin furor

Butts categorically denies the accusation that he or anyone else in the PMO improperly pressured former attorney general Jody Wilson-Raybould

Lost a ring? This B.C. man will find it for you

Chris Turner founded The Ring Finders, an international directory of metal detector hobbyists

Poverty coalition has high hopes for B.C. poverty reduction strategy

Funding allocation expected to be released with 2019 budget

‘How did we get here?’: B.C. mom of transplant recipient worries about measles outbreaks

Addison, 7, cannot get a live vaccine because she has a heart transplant

NDP Leader Jagmeet Singh calls for public inquiry over SNC-Lavalin questions

Vancouver member of Parliament Jody Wilson-Raybould resigned from cabinet last week

Canadian airlines waiting for guidance from Ottawa over X gender option

Major U.S. airlines said they will change their process so passengers can identify themselves along non-binary lines

Moose Hide campaign takes message to Canadian schools

Campaign launches new K-12 education platform

‘Violent’ B.C. man wanted on Canada-wide warrant

Prince George man with ties to Vernon sought by police

Homicide police investigate assault turned deadly in Surrey

60-year-old man died at hospital after assault

Most Read