Drugs in sewers: Measuring biomarkers for legal and illicit drugs and antimicrobial resistance

Wastewater-based epidemiology (WBE) is the analysis of chemicals found in wastewater with the objective of gathering information on human activity within communities. At The University of Queensland Alliance for Environmental Health Sciences, Research Fellow Jake O’Brien and his colleagues are using a WBE approach to gather revealing insights on how legal and illicit drugs are being consumed across Australia.

The team’s research measures biomarkers of a range of drugs to reveal population habits, such as pinpointing locations where certain drugs are used most and the times when they are used most often. Jake was the guest speaker at the Global Water Institute’s Water Issues Commentary Seminar on Thursday 12 March, where he shared the methodology and results of his team’s research and offered insights on how WBE may be applied for antimicrobial resistance surveillance.

To get these insights, we have to rely on data from dozens of sources, so it is an extremely multidisciplinary science Jake O'Brien, Research Fellow, The University of Queensland

 Jake introduced the topic by sharing some interesting findings, including one study which revealed cocaine use is more prevalent on weekends, while methamphetamine is used more consistently throughout the week. Another study, funded by the Australian Criminal Intelligence Commission, combined information on the dates and locations of significant police drug seizures with WBE data, finding that drug use reduced markedly in certain geographies immediately following the seizures—however not necessarily in the state where the drug seizure occurred.

And it’s not only illegal drugs that can reveal interesting insights—high levels of pharmaceuticals in certain suburbs can inform where health conditions such as where and when hay fever and asthma are most common, potentially due to environmental conditions. Moreover, census data can be accessed to reveal correlations between age, socio-economic status and drug use, yielding often surprising results.

Jake said that while wastewater can reveal many interesting things, it does have its limitations. It can’t tell us about individual behaviour profiles, the administration form of the drug, co-consumption, price, purity, dose frequency, misuse frequency, individual compliance, drug use preferences, user health, or the socio-demographic characteristics of individuals. Significantly, it also can’t divulge the underlying reasons why drug use is changing, and cannot usually distinguish between diverted and therapeutic use.

Jake also offered an overview of  the wastewater journey and the sophisticated process that is needed for effective interpretation, saying, “The simple fact of the matter is that to get these insights, we have to rely on data from dozens of sources, so it is an extremely multidisciplinary science.”

When looking at what makes a good WBE marker of chemical consumption, Jake says there are four key attributes. These are that it must be excreted through urine, it must be detectable in wastewater, it must be stable in wastewater and it must have a unique source – from the human metabolism. Jake’s own research has also focussed on understanding additional properties biomarkers require when the goal is to use them to determine the daily size of the population sampled.

With WBE becoming increasingly likely to monitor antimicrobial (or antibiotic) use and resistance at the population level, Jake has explored how this compares to what is being done with illicit drugs. He said that for antimicrobial compounds, a lot less in known such as their in-sewer stability or if its possible that metabolites are formed in the sewer, not just from human consumption. So while WBE shows promise for antimicrobial use and antimicrobial resistance surveillance, further research is still required to determine its suitability.

Jake's presentation can be viewed on the GWI YouTube channel.

 Jake O’Brien is also a Chief Investigator on the National Wastewater Drug Monitoring Program which is funded by the Australian Criminal Intelligence Commission. The program provides quarterly reports on the consumption of illicit drugs and legal drugs with abuse potential from more than 50% of the Australian population. Jake's research focuses on the development and use of biomarkers in wastewater, the use of biomarkers in wastewater-based epidemiology; and the measurement and reduction in uncertainties associated with wastewater-based epidemiology.