Written by Benjamin Tscharke, PhD Candidate, The University of South Australia
for the National Science Communication Challenge
Drugs of abuse cause immeasureable economic and social costs to the community; which begs the question: how much is really out there?
Drugs such as Ice (crystal methamphetamine) have caused problems in the community for a long time.
In many cases the effects of the drug cause users to exhibit criminal and antisocial behaviours or impose significant health risks to themselves or others.
Recently, media reports have been becoming more alarmist about ice use, suggesting the problems have been intensifying in the last few years.
Much of this reporting comes from colloquial anecdotes, arrest rates, drug seizures, patient presentations at hospitals or drug treatment facilities, or levels of crime.
Many of these reporting methods can be subjective, for example: if drug seizures or drug arrests increase, is that an indication of more drugs in the community? Or is it due to an increase in police efficiency?
How does the amount of drug seized compare with how much drug is available on the streets?
Is it just the tip of the iceberg?
Is there some objective way to determine how much of a drug is being used in our communities?
Put simply, yes. It is possible.
It is well known that drugs can be detected in several body fluids, including urine. After a drug has been administered, it is metabolised by the body and ends up in the urine in a modified form (as a metabolite or metabolites) or as the parent drug.
Testing for drug metabolites in urine is one of the main methods for non-invasive drug testing. Such tests are common in many workplaces, especially for industries which involve the operation of dangerous equipment.
Any drugs which are present in a urine sample can be extracted out and then analysed to determine what drugs have been used. Yet, this can only determine drug use of indiviuals.
These basic drug testing principles can be applied to samples containing urine from several hundreds-of-thousands of people, whole communities, and even cities.
How, you ask?
Each time a toilet is flushed the contents travel through the sewer network to a wastewater treatment plant. Typically, cities have treatment plants that cater for several hundreds-of-thousands of people. At the plant, all of the communities' urine passes through the inlet pipe, along with the drug metabolites.
At this point the wastewater can be sampled over the course of a day to yield a representative sample of the total daily inflow. In a similar way to conventional urine testing, the drugs in the wastewater can be extracted out and analysed. Based on levels in a representative sample, the weight of pure drug can be calculated for each day in the area under investigation.
And thus, the whole iceberg can be revealed.
This may sound like a load of science-fiction to many, however this field of research, termed Wastewater Analysis, is carried out in more than 70 cities throughout Europe as well as some in the USA, Canada, China and Australia (among others). Collected data can be used by health agencies to tailor drug reduction strategies or awareness campaigns, and determine efficacy of drug-reduction targets.
Monitoring how drug-use changes over time gives insights into drug use behaviour and can also help determine how effective government (or police) measures are at reducing the drug problem.
After all, the quantities of drug used in our communities can now be revealed: the whole iceberg.