The most comprehensive wastewater study ever undertaken in Australia has revealed the presence of 15 new psychoactive substances in the country’s metropolitan and regional wastewaters over the past three years.
The research team, led by Richard Bade, an analytical chemist at the University of South Australia, took wastewater samples covering all states and territories bi-monthly from October 2017 to June 2018 and October 2019 through February 2020.
According to the study, a range of new stimulants gained popularity over the sampling timeline, with N-ethylpentylone and ethylone among the most prevalent. Bath salts, or synthetic cathinones, were not detected in wastewater early in the sampling period, but ended up being the most prevalent by 2020.
The study, published in Science of The Total Environment, illustrated what the authors call a “wax and wane” cycle of many drugs. This is likely due to supply and demand of designer drugs, as well as suppliers consistently changing the formula of their drugs to evade forensic and police detection.
For example, N-ethylpentylone was initially seen widely in South Australia, Victoria and the Australian Capital Territory, but by 2019, the bath salt was only found in Tasmania's wastewater. Conversely, eutylone was not found in the first sampling period that ended in 2018, but was the most prevalent NPS in all states and territories in late 2019 and early 2020, with the exception of South Australia.
“Little is known about safe doses of NPS, which adds to the concern surrounding them," said Bade, adding that more pharmacokinetic studies of these substances would be extremely helpful and serve public health purposes.
According to drug seizure data and surveys of Australian drug users, synthetic cannabinoids are actually the most widely used NPS in the country, but they are notoriously difficult to detect in wastewater. On the other hand, cathinones can be easily identified.
Unlike the United States, which has laws in place that render novel psychoactive substances illegal, these drugs have a more complex history in Australia, with different laws applying to NPSs across the country.
In South Australia, Queensland, New South Wales and Victoria, for example, there is a blanket ban on possessing or selling any substance that has a psychoactive effect other than alcohol, tobacco and/or food. In other states and territories, specific novel psychoactive substances are banned and new ones are regularly added to the list. This means that a drug that was legal to sell or possess today, may be illegal tomorrow—adding another wrinkle to forensic detection, as well as contributing to the wax and wane cycle seen in the study’s results.
As the U.S. has seen in recent years, Bade noted that novel psychoactive substances are increasingly popular at music festivals, where there tends to be rampant and escalating alcohol and drug use.
“There is little information relating to potential side effects, but they can include paranoia, hallucinations and panic attacks and we know they have caused some deaths at music festivals, with people mistaking them for ecstasy,” said Bade.
Bade’s wastewater study sampled up to 53 locations over three years, covering more than half of Australia’s population.
Photo: Synthetic cathinones, also known bath salts. Credit: University of South Australia