Seven psychoactive drugs have been detected in Australian wastewater for the first time, a three-year surveillance program has found.
Wastewater testing has revealed the presence of synthetic drugs including mephedrone (commonly referred to as meow meow), ethylone and eutylone, which have stimulant effects akin to MDMA.
The drugs are known as new psychoactive substances, a group of compounds that often mimic the effect of existing illicit substances, but which differ chemically and may not be controlled by international drug conventions.
Researchers monitored wastewater in four Australian cities over the New Year period in 2019-20, 2020-21 and 2021-22.
The study’s lead author, Dr Richard Bade at the University of Queensland, said: “There are so many of these new psychoactive substances and new ones popping up every year, and we have a relatively limited knowledge of these compounds.”
Mephedrone, ethylone and eutylone belong to a class of drugs known as synthetic cathinones, which act as stimulants.
David Caldicott, an associate professor and clinical senior lecturer at the Australian National University who was not involved in the study, has previously detected these cathinones in his pill-testing research.
“What we’re seeing at the moment in our pill testing is that a lot of people are acquiring tablets or capsules or powders which they believe to be MDMA – or ecstasy – which are in fact cathinones,” he said.
“Some of them are unpleasant and increasing in prevalence and replacing drugs that are not quite as dangerous as they are. These things can lend themselves to overdose, and it’s quite clear that they have been responsible for people’s deaths internationally.
Caldicott said the new wastewater detections may have arisen as a result of expanded surveillance for emerging compounds, as well as from increasing consumption of such drugs.
“There’s probably a growing volume of consumers who are producing an equivalent increased volume of urine which will contain these products,” he said. “It’s a combination of observer bias and also the change in the patterns of consumption.”
Production of these compounds was “almost certainly not local”, he added.
“A lot of what we think we know about drugs in Australia comes from politely inquiring of the consumer what it is they think they’ve taken,” Caldicott said. The benefit of wastewater detection and pill testing is that they work complementarily as direct monitoring techniques.
The study, published in the journal Water Research X, was part of an international collaboration that surveilled wastewater in 16 countries.
“For the majority of the compounds that we found, Australia is on the lower side which can probably be considered a good thing,” Bade said.
The researchers noted that there was a decrease in detections of psychoactive substances over the 2020-21 New Year period, coinciding with the Covid pandemic.
