Water testing of Adelaide’s wastewater has revealed a 25% spike in methamphetamine use over the past year, and a tripling of consumption over the past five years.
Under the project, commissioned by Drug and Alcohol Services South Australia, samples have been taken from four SA Water metropolitan wastewater treatment plants every two months since December 2011.
The samples have been tested for four stimulants, six opioids and 11 psychoactive substances.
The University of South Australia’s School of Pharmacy and Medical Sciences latest report stated: “Frequent wastewater sampling and analysis over prolonged periods has yielded valuable insights into long-term drug use trends, in some instances revealed important within-year trends, and demonstrated the differing patterns of use of drugs on weekends compared to weekdays”.
The spike in methamphetamine use was the most marked trend – rising from around 150 doses per week per 1000 people to more than 450 doses per week per 1000 people.
Temporal trends also showed increasing use of cocaine, oxycodone and fentanyl, while there was a decrease in rates of MDMA, BZP and methylone use.
Use of other opioids and cannabis was generally stable across the study period.
“Opioids and cannabis were used at a consistent level through the course of the week, while use of stimulants and some NPS increased on the weekend,” the UniSA report stated.
“Seasonal differences in use were observed for MDMA and cannabis where – on average – MDMA use was approximately 90% higher in December than in other months and cannabis use was approximately 45% lower in February.”
Report co-author Cobus Gerber told New Scientist the raw sewage samples were analysed using mass spectrometry and provided a unique insight into drug use.
“The advantage is that it’s almost instantaneous, so it tells you what is happening across the whole population right now,” Gerber said.
“That’s better than asking people what drugs they took a week ago, then collating the data and producing a report a year later.”