The latest findings from the largest European project monitoring illicit drug use through wastewater analysis are released today in Wastewater analysis and drugs — a European multi-city study, published by the Europe-wide SCORE group, in association with the European Union Drugs Agency (EUDA). The rise in MDMA, cocaine and amphetamine detections compared to 2023 takes centre stage in this year's study, along with decreases in cannabis detections.
The project analysed wastewater in a record 128 European cities from 26 countries (24 EU, Türkiye + Norway) to explore the drug-taking behaviours of their inhabitants. The study analysed daily wastewater samples in the catchment areas of wastewater treatment plants over a one-week period between March and May 2024. Wastewater samples from some 68.8 million people were analysed for traces of five stimulant drugs (amphetamine, cocaine, methamphetamine, MDMA/ecstasy and ketamine) as well as cannabis.
While rises were seen in the detections of three of the stimulants (MDMA, cocaine, amphetamine), diverging patterns were observed for methamphetamine and ketamine. Despite results varying considerably across the study locations, it is noteworthy that all six illicit drugs investigated were found in almost every participating city. Less divergence is seen in drug-taking habits between large and small cities for some drugs (see 'City variations' below).
The SCORE group has been conducting annual wastewater monitoring campaigns since 2011, when 19 cities from 10 countries participated and four stimulant drugs were studied. Seventy-six cities have participated in at least five of the annual wastewater monitoring campaigns since 2011, allowing for time trend analyses.
Key findings
• MDMA : Of the 76 cities with data for 2023 and 2024, 41 reported an increase in MDMA detections, 24 a decrease (mostly in cities central Europe and in the Baltic region) and 11 a stable situation. The highest mass loads of MDMA were found in wastewater in cities in Belgium, Czechia, the Netherlands and Portugal.
• Cocaine : Cocaine residues in wastewater remain highest in western and southern European cities (particularly in Belgium, the Netherlands and Spain), but traces were also found in the majority of the eastern European cities, where some increases continue to be observed. Of the 72 cities which had data for 2023 and 2024, 39 reported an increase, while 17 cities reported no change and 16 cities showed a decrease. The rise in cocaine detections is a trend observed since 2016 (despite some fluctuation during COVID-19 lockdowns). Participating cities in Brazil, Chile and Switzerland show similar levels of use to the European cities with the highest loads (1).
• Amphetamine : The level of amphetamine residues was highest in cities in the north and east of Europe (Belgium, Germany, the Netherlands, Sweden and Norway). Much lower levels were found in cities in the south, although the most recent data show some increases. Of the 68 cities with data on amphetamine residues for 2023 and 2024, 34 reported an increase, 14 a decrease and 20 a stable situation.
• Methamphetamine : Traditionally concentrated in cities in Czechia and Slovakia, this drug is now also present in cities in Belgium, Croatia, the east of Germany, Spain, the Netherlands and Turkey and several northern European countries (e.g. Denmark, Lithuania, Finland and Norway). Of the 71 cities with data for 2023 and 2024, 32 reported an increase in residues, 27 a decrease and 12 a stable situation. In the remainder of the European cities, methamphetamine loads were low to negligible, although some increases were reported in central European cities.
• Ketamine : The 2024 data reported by 82 cities revealed relatively low levels of ketamine residues in municipal wastewater. Of the 42 cities that have data on ketamine residues for 2023 and 2024, 14 reported an increase, 15 a stable situation and 13 a decrease. The highest mass loads of ketamine were found in wastewater in cities in Belgium, the Netherlands, Hungary and Norway.
• Cannabis : The highest loads of the cannabis metabolite THC-COOH were found in western and southern European cities, particularly in Spain, the Netherlands, Norway and Portugal. In 2024, decreasing trends were seen, with 25 cities out of 51 reporting a decrease and 13 cities reporting an increase since 2023.
• City variations: For cocaine, higher loads were detected in larger cities. For methamphetamine and MDMA, no marked differences were seen when comparing results from large and small cities. This suggests that, in some cases, ‘urban’ patterns of drug use may be spreading to smaller towns. For the remaining three substances analysed, no clear pattern emerged, consistent with findings from previous years.
• Weekly patterns: 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 use in recreational settings (cocaine, ketamine and MDMA) at the weekend (Friday–Monday). In contrast, residues of amphetamine, cannabis and methamphetamine were distributed more evenly throughout the week.
Alexis Goosdeel, EUDA Executive Director says: 'Wastewater monitoring offers invaluable insights into the dynamics of drug use and supply, and is a powerful tool for boosting preparedness against emerging challenges. This year’s study, covering a record 128 European cities, paints a clear picture of a drugs problem that is both widespread and complex, with all six substances detected in nearly every location. As the potential of wastewater analysis grows, we look forward to further developing our work in this area to better inform public health and policy responses.'
Interactive features
Today’s study includes an innovative interactive map allowing the user to look at geographical and temporal patterns and to zoom in on results by city and by drug. This interactive feature has been designed to be accessible and user-friendly and to perform better on mobile and desktop devices. In line with the EUDA’s commitment to open data, all of the source tables behind the tool can be easily downloaded by researchers, data journalists or anyone interested in using the data in their work.
