Synthetic opioids linked to spate of overdose deaths found in wastewater across Australia

The Guardian

28-04-2025

Synthetic opioids a thousand times stronger than morphine and an animal sedative used to lace street drugs have been detected in Australia's wastewater.
The discovery has been described as a 'red flag' and comes as the deadly class of synthetic opioids – nitazines – claims dozens of lives in Australia.
Researchers tested 180 wastewater samples from 60 sites nationwide and detected five different nitazenes in 3-6% of samples.
These synthetic opioids have become one of the fastest-growing psychoactive substances in the world since emerging in the illicit market in the late 2010s.
The use of nitazenes, either intentional or not, has resulted in overdoses in Australia, with compounds sometimes mixed into illicit drugs such as heroin and ketamine as well as MDMA, also known as ecstasy.
The study of Australian wastewater collected from 60 sites over three days last August also found high rates of xylazine, a sedative used by vets on animals and not approved for human use in Australia.
It was detected in one in four samples.
'Given the potency of nitazenes and the health complications associated with xylazine, even low-level detections are a red flag,' the study's co-first author, University of South Australia academic Emma Keller, said on Monday.
The researchers developed a highly sensitive method to detect the substances in wastewater, providing a potentially vital early warning tool to health authorities.
'This is the first time a comprehensive suite of nitazene compounds and xylazine has been monitored in Australian wastewater,' co-first author Corbus Gerber said.
Dr Keller and Dr Gerber's method could be quickly updated to detect new derivatives as they emerge. That would be an essential capability as drug manufacturers continue to tweak chemical structures to evade legislation, the university said.
The research was published on 22 April in the latest issue of peer-reviewed journal Environmental Science and Pollution Research.
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One funder was the Australian Criminal Intelligence Commission, which is among several public authorities alarmed at the surging use of nitazenes.
Since 2021, nitazenes have been detected in every state and territory, and have been linked to at least 23 overdose deaths in Victoria and seven in South Australia alone.
A coroner in recent weeks concluded four people, one as young as 17, who died in the same Melbourne house in June 2024 had overdosed on cocaine laced with nitazenes.
Health authorities in New South Wales and South Australia have issued multiple urgent warnings about nitazenes being sold as black-market oxycodone or other substances.
Customs officials intercepted more than 60 imports of the killer group of drugs in 2023 and 2024, largely originating from Hong Kong, the UK and Canada.
Australian federal police have described nitazenes 'like playing Russian roulette' with lives.