The world’s waters are polluted: no news there. We’ve been living with this issue for decades, which shows little sign of abating… But if we can’t fight it, we can at least study it. Indeed, analyzing our river systems can offer valuable insights into population health. That’s the aim of the new study by the European Union Drugs Agency (EUDA), which analyzed wastewater from 115 cities in 25 countries across Europe.
This represents the most comprehensive analysis to date in wastewater research, and offers a unique glimpse into the consumption habits of different European populations.
The SCORE group (Sewage analysis CORe group — Europe) has been conducting this work since 2011, allowing researchers to compare illicit drug loads in the region over 10 consecutive years. Most of the composite samples were taken within a single week in each city, in the last case between March and May 2025. To detect the presence of various drugs, urinary biomarkers for amphetamine, methamphetamine, ketamine, and MDMA were analyzed, as well as the main urinary metabolites of cocaine and weed.
Another factor examined was variation by day of the week. For example, more than 75% of the cities showed higher concentrations of cocaine and MDMA on weekends compared to weekdays. About half of the cities showed the same pattern with ketamine. This is not the case for cannabis, amphetamine, or methamphetamine, whose use appears to be more evenly distributed throughout the week. The presence of heroin could not be accurately measured given that its specific metabolite is unstable in wastewater.
Drugs in Europe, according to wastewater
The study found a wide variation in samples across different regions, although all the illicit drugs investigated were found in almost every city. Below is a breakdown by substance, along with details of its prevalence across the European continent:
Cocaine: Overall, …
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Author: Marian Venini / High Times
