Wastewater tested in Halifax in 2023 contained almost twice the amount of cannabis metabolites compared with samples taken from other big cities in Canada, like Toronto or Montreal.
The results are from a survey conducted in November 2023 by Statistics Canada, which tracked various drug metabolites in the wastewater in Halifax, Montreal, Toronto, Saskatoon, Edmonton and Vancouver.
In Halifax, the survey found 748 milligrams of THC metabolites per 1,000 people per day — well above the 448 milligrams average among the surveyed cities. THC is the compound in cannabis that causes the drug’s psychoactive effects.
Lisa Oliver, chief of the survey, said researchers continuously collected samples from wastewater plants over a one-week period and calculated the concentration of drug derivatives found in them.
The project started in 2019 as a way to measure substance consumption because “drugs, and in particular illicit drugs, can be very difficult to understand” using traditional survey …