Pre-pandemic, the average person on the street would likely never have heard of wastewater testing. Now, with almost-daily news reports about COVID-19 fragment detection in sewage, the general public knows that testing wastewater can be one vital aspect of a public health strategy.
The same idea has existed for illicit and pharmaceutical drugs for decades. In Australia, regular wastewater testing began in 2016, co-ordinated by the Australian Criminal Intelligence Commission (ACIC) using expertise at The University of Queensland and the University of South Australia.
A little history
ACIC recognised around a decade ago that existing sources of data did not measure demand for drugs or quantities of the substances that were being consumed.
“Understanding drug consumption at a population level supports effective allocation of resources,” says Shane Neilson, ACIC’s Principal Advisor Drugs. “It also allows the progress of demand, supply and harm reduction strategies to be monitored.”
What can wastewater testing tell us?
“Much of what we understand about illicit drug markets, we know exclusively and uniquely from wastewater,” says Shane. “We can, for example, arrive at a reliable figure for the quantity of the drugs that are being consumed and therefore the value of the markets. And that tells you how much, at a minimum, is being laundered in the criminal economy of Australia.”
Much of what we understand about illicit drug markets, we know exclusively and uniquely from wastewater.
As well as overall quantities of drugs, wastewater testing can give insights into use patterns across the week.
For a drug like ecstasy (MDMA), cocaine or alcohol, you get a peak on the weekends, which can suggests most of the punters are not dependent.
“For a drug like ecstasy (MDMA), cocaine or alcohol, you get a peak on the weekends, which suggests most of the punters are not dependent,” says Roger Nicholas, Senior Project Manager at the National Centre for Education and Training on Addiction (NCETA). “But with a drug like methamphetamine, there’s not much variation across the week – that tells me most of the people would be dependent on it.”
Let’s get specific
The 14th report of the National Wastewater Drug Monitoring Program was released at the end of October this year by ACIC. The report is based on data collected in April 2021 from 56 wastewater sites across the country, accounting for around 56 per cent of Australia’s population.
The most-consumed drugs across the board this time are alcohol and nicotine and the most-consumed illicit drug is methylamphetamine. Downward trends are seen for oxycodone, fentanyl, heroin, cocaine and MDMA, possibly due to the impact of COVID-19 restrictions.
As in previous reports, consumption has been shown to vary across states and between city and regional areas. Cities have seen higher consumption of cocaine, MDA, heroin, ketamine and, for the first time, MDMA. The average regional consumption of alcohol, nicotine, methylamphetamine, oxycodone, fentanyl and cannabis is higher than in cities.
ACIC notes in this Report 14 that impacts of Operation Ironside – a three-year long Australian Federal Police and United States Federal Bureau of Investigation operation – are more likely to be seen in the next reporting period (Report 15 will be published in February 2022).
The report includes international comparisons which show that Australia has the second-highest methylamphetamine consumption compared to 23 other countries. (We rank seventh and 16th for MDMA and cocaine respectively.)
Cannabis – a particularly tricky drug to test for due to consumption of different parts of the plant as well as uncertainties around breakdown rates both in the body and in sewage – is included for the first time, with Australia ranking seventh out of the 16 countries able to test for the THC metabolite.
Regular testing and reporting means that changes can be understood in relation to local, national and world events. For example, decreases in average consumption of MDMA since record highs in December 2019 pre-dated COVID-19 restrictions. Report 14 notes that ACIC believes the decrease commenced due to decreasing imports to Australia by serious and organised crime groups and then continued during lockdowns.
Getting techy: how does it work?
Wastewater analysis involves analytical and environmental chemists, epidemiologists and pharmacologists. In the lab, liquid chromatography and mass spectrometry are the techniques used for analysis.
“Liquid chromatography is a method to separate dissolved chemicals in mixtures,” explains Associate Professor Cobus Gerber, Head of the Population Health Chemistry research group at the University of South Australia.
Mass spectrometry… is compound-specific and provides high accuracy.
Associate Professor Cobus Gerber
“Mass spectrometry is used to determine the amount of target compounds in a sample. It filters compounds based on their chemical mass and the unique fragments they produce in an electric field. It is compound-specific and provides high accuracy.”
If that level of detail goes above your head or takes you back to high-school chemistry, never fear. “I don’t understand all the science and I never will,” says ACIC’s Shane Neilson. “What I do understand is mathematically it makes sense… so I’m confident that when you’re looking at population level analysis, you can take the figures to the bank.”
“It’s very mature science,” confirms Roger Nicholas from NCETA. “Wastewater has been tested for a variety of things for decades.”
How are analysis insights used?
Cobus Gerber emphasises that wastewater drug monitoring is not aimed at locating individual users. “It’s much more about understanding drug-taking behaviour and implementing suitable responses,” he says. “Our research findings are disseminated to government agencies in near-realtime and, if any unusual drugs show up, we report that to our local drug early warning system.”
“There’s no doubt that wastewater analysis is important to everyday Australians,” says Shane Neilson. “All stakeholders, including members of the public, can develop a common and informed understanding of trends in drug consumption. The Australian Government and increasingly state and territory governments are enthusiastic clients of wastewater analysis. It provides an evidence base for and informs their decision-making.”
Roger Nicholas, who started his career in ambulance and nursing, including in drug and alcohol treatment programs, uses his home city of Adelaide as an example. “We can tell the size of the Adelaide market and working dollar value based on consumption in the city. We can also see variations in patterns of opioid prescribing, including in areas where there’s a fairly elderly population, so it’s a useful check in that way,” he says. “We can also tell the impact of a seizure of, say, methamphetamine on consumption in Adelaide. We know it takes a couple of months for a stock to run out as there’s usually some stockpiling, and then there’s a drought.”
Reporting to the public follows strict privacy guidelines. “We never put site locations into public reports,” says Shane Neilson, “but we certainly have those conversations with local health and law enforcement agencies so that if there’s a problem in a particular location they can direct the resources to where they need to go.”
Is there anything wastewater analysis can’t do?
“It doesn’t provide perfect insight,” says Roger Nicolas, adding that wastewater is one part data collection, alongside surveys and data concerning drug seizures and arrests. “It is just part of the picture.”
“You can’t tell the characteristics of the people who are using; you need population surveys for that,” he says. “You can’t tell what suburbs and streets people are using drugs in.”
He notes you also can’t identify patterns of use. “You don’t know whether you’ve got a very large number of people using a small amount of drug or a small number of people using huge amounts,” he says, “so it does have its limitations, but it’s one of the most accurate ways of telling you what quantum of drugs – whether pharmaceutical or illicit – are in use in the community at any point in time.”
“It’s also less intrusive as a researcher,” says Shane Neilson. “As long as you’re connected to the sewage system, there’s no hidden populations.”
Experts from around the globe actively work together in refining techniques and undertaking joint research. “The field has strong international collaboration,” says Dr Richard Bade, Research Fellow at The University of Queensland’s Queensland Alliance for Environmental Health Sciences (QAEHS). He notes that the most recent iteration of a yearly inter-laboratory exercise saw participation from 100 cities across 34 countries. (The exercise is run by the fabulously acronymed group Sewage Analysis Core Group Europe, or SCORE.)
Richard’s recent scientific paper published in the Water Research journal looking at new psychoactive substances (NPS) across eight countries on New Year’s Eve was an example of this.
“Sampling and analysis techniques have been standardised internationally so meaningful international comparisons of drug consumption are possible,” concurs Shane Neilson. “And, the innovative and world-leading nature of Australian wastewater analysis means it can be exported to the world.”
The lighter side
Wastewater testing is not exactly the most glamorous job in the world, nor the easiest to explain.
ABC News reported that the person taking samples from sewage ponds in Darwin for COVID-19 testing needed to take along a “croc spotter” thanks to the water being home to at least one sizable saltwater crocodile.
Lab-based work might be safer but Dr Richard Bade laughs when asked what sort of response he gets to telling people at parties (remember them?) what he does for a living. He says the most out-there comment was someone asking, with great interest, whether it might be possible to extract the drugs from the sewage in order to use them again. “It’s all about the circular economy,” jokes Richard, before confirming his clear response. “Of course that’s not possible.”
– Vivienne Pearson