Determining changes in new psychoactive substance use in Australia by wastewater analysis

Measuring community consumption of new psychoactive substances (NPS) is notoriously difficult to assess by traditional means such as surveys and seizure data. Previously, we used the approach to demonstrate the prevalence of NPS on a national scale. In the current study we explored the temporal resolution for the analysis of NPS in wastewater from Australia. Samples covering all States and Territories in Australia and both metropolitan and regional areas and were collected bimonthly from October 2017-June 2018 and October 2019-February 2020. A qualitative screening method was applied, screening for 201 NPS. In total, 15 substances were found from a variety of classes of NPS. The most prevalent class was synthetic cathinones, with pentylone, N-ethylpentylone and ethylone found in all periods in at least one site in the earlier sampling period, as well as the amphetamine-like paramethoxyamphetamine (PMA). In the latter period, synthetic cathinones were also the most prevalent, including eutylone, marking the first time that this compound has been detected in wastewater. This study shows the application of wastewater analysis to detect outbreaks of NPS use and temporal differences among sites.