Wastewater samples show that Nova Scotia’s capital city leads far larger cities in rates of cannabis, cocaine and ecstasy consumption

It appears that Halifax residents consume higher rates of cannabis than those living in four of Canada’s largest cities, or so suggests wastewater samples from the last five months of 2020.

Posted online this week, figures from Statistics Canada show the counts for drug metabolites in wastewater in five Canadian cities: Halifax, Montreal, Toronto, Edmonton and Metro Vancouver.

Considering the load per capita — which StatCan explains is grams per 1 million people per day — Halifax’s rate in December 2020 was 22.7, up from about 16.4 in August of that year.

That compared to 135.5 for Montreal, down from 168.5; 137.6 for Toronto, down from 148.2; 431.6 for Edmonton, down from 612.3; and 519.9 for Metro Vancouver, up slightly from 515.5, the figures show.

But for each month during the last five of 2020, counts for cannabis, cocaine and ecstasy are noted as being higher than for the four other, considerably larger cities.

Specifically for tetrahydrocannabinol carboxylic acid (THC-COOH), a major metabolite of THC, Halifax had a measure of about 1,123.2 in December 2020 compared to approximately 252.2 in Montreal, around 298.3 in Toronto, about 633.3 in Edmonton and approximately 428.4 in Metro Vancouver.

For cocaine, the measure was around 350.4 in Halifax, approximately 83.4 in Montreal, about 174.6 in Toronto, around 198.2 in Edmonton and about 278.7 in Metro Vancouver.

As for ecstasy, Halifax again had the top rate at about 54.2. This was well above the approximately 24.3 in Montreal, around 22.9 in Toronto, about 26.8 in Edmonton and approximately 28.4 in Metro Vancouver.

The idea behind the survey, samples for which may be gathered weekly, was “to detect and measure trends in the viral load of SARS-CoV-2 through wastewater epidemiological surveillance, which could be used as an indicator for the total community burden of COVID-19 infections,” StatCan explains.

“The drug component of this survey is collected on a monthly basis, and estimates the load per capita of various drugs of concern,” it adds.

Back in 2019, when the effort was at the pilot test stage and involved samples collected between March 2018 and February 2019, Yargeau Laboratory at McGill University’s Department of Chemical Engineering completed the review.

At that time, it was found that Montreal and Halifax had the highest levels of cannabis consumption, while Edmonton samples showed the lowest.

Survey results from 2021 indicated that the use of cannabis, fentanyl and methamphetamines rose since the start of the pandemic.

At that time, the Public Health Agency of Canada noted the “rose feelings of isolation, stress and anxiety and limited availability or accessibility of services for people who use drugs” over the course of the pandemic had likely contributed to the increases.

A separate review involving Tallinn, Estonia found that cannabis, amphetamines and cocaine were the top three most-consumed substances in the area, according to wastewater samples.

The samples taken over a week in March 2019 show that consumption of MDMA and cocaine appeared to be a weekend thing, while cannabis counts indicated relatively steady consumption during weekdays.

Another study, looking specifically at wastewater and cannabis in Washington state, “suggests a significant increase in consumption” following legalization.