A recent study by Europe-wide SCORE group, in partnership with the EU drugs agency (EMCDDA), has released its latest findings from the largest European project in the science of wastewater analysis. The project analyzed wastewater samples from a record 104 European cities from 21 countries to explore the drug-taking behaviours of their inhabitants. Daily wastewater samples were analyzed for traces of five illicit stimulant drugs (cocaine, amphetamine, methamphetamine, MDMA/ecstasy and ketamine) as well as cannabis. The latest results reveal a continued rise in cocaine detections, a trend observed since 2016. The methamphetamine situation appears to be evolving, with more cities reporting traces of the drug. A mixed picture emerges for the remaining substances where trends can be observed.
The study highlights that despite detections varying considerably across the study locations, all six illicit drugs investigated were found in almost every participating city. The findings are significant as wastewater samples can provide an early warning of emerging health threats and increase insight into drug use and supply dynamics. Wastewater surveillance is also growing in its potential for targeting and evaluating localized public health responses and policy initiatives.
Cocaine residues in wastewater remained highest in western and southern European cities (particularly in Belgium, the Netherlands, Spain and Portugal), but traces were also found in the majority of the eastern European cities, where some increases were observed. Methamphetamine, traditionally concentrated in Czechia and Slovakia, is now also present in Belgium, the east of Germany, Spain, Cyprus and Turkey, and several northern European countries. The level of amphetamine residues varied, with the highest loads reported in cities in the north and east of Europe (Belgium, Germany, the Netherlands, Finland and Sweden) and much lower levels in cities in the south.
The findings reveal differences between cities in the same country, which may be partly explained by their different geographical, social and demographic characteristics (age distribution, universities, nightlife). In most countries with multiple study sites, residues were higher in large cities than in smaller locations for three stimulants (cocaine, methamphetamine, MDMA). No such differences were detected for amphetamine and cannabis. The study also shows that wastewater analysis can detect fluctuations in weekly patterns of illicit drug use. More than three-quarters of the cities showed higher residues of drugs often associated with recreational patterns.
The latest wastewater analysis study provides important insights into the drug-taking behaviours of European citizens, and the results can inform and shape public health responses and policy initiatives across Europe. The continued rise in cocaine detections and evolving methamphetamine situation highlight the need for targeted and effective interventions to reduce drug use and supply across the continent.