Detection of cocaine in European cities' wastewater has continued to increase, despite efforts to limit the consumption and smuggling of illicit drugs.
Europe's war on drugs seems to be heading in the wrong direction, as a new scientific study analysing wastewater shows an increase in the use of illicit drugs across European cities.
The latest results from the collaborative study conducted by the SCORE group and European Monitoring Center for Drugs and Addiction (EMCDDA) detected metabolites of cannabis, cocaine, methamphetamine, amphetamine, MDMA, and ketamine.
The study, conducted across 104 cities in 21 countries, revealed a rise in cocaine and methamphetamine detection in Europe's wastewater.
"Today’s findings paint a picture of a drug problem that is both widespread and complex, with all six substances detected in almost every location. Now an established science, wastewater surveillance provides us with increasing insight into the dynamics of drug use and supply," EMCDDA director Alexis Goosdeel said in a statement.
Cocaine, in particular, was detected in all cities included in the study and its increasing figures points to wide availability and use amongst the general public.
More than half of the 66 cities with data for both 2021 and 2022 showed an increase in cocaine residues, the majority of which belong to Western and Southern Europe.
Cities from Belgium, the Netherlands, Spain, and Portugal showed the highest prevalence of cocaine in their wastewater samples.
The Swiss cities of Basel, Geneva, and Zurich also contained some of the highest residues of cocaine metabolites.
The appearance of the Dutch, Belgian, and Spanish cities can be attributed to the increasing trade of cocaine using the ports of those cities, according to an EU drug market analysis published in 2022.
Belgian ports seized the most cocaine in 2020 in Europe, almost ten times higher than in 2010; followed by the Dutch and Spanish ports.
Despite the year-on-year increase in cocaine seizures, the simultaneous increase in cocaine detection in wastewater implies greater availability for usage.
"We are now facing a growing threat from a more diverse and dynamic drug market, that is driven by closer collaboration between European and international criminal organisations," Goosdeel added.
Similarly, the latest wastewater analysis has also shown that cannabis continues to be the most used illicit drug in Europe, despite a drop in detection amount in many cities.
However, the trend shows drops in 15 cities, while the cannabis metabolite increased in wastewater of 18 cities compared to 2021.
The study also showed an increase in cannabis and cocaine quantities during the weekends, which according to the study, can be due to increased recreational usage.
However, the study cannot provide information on the frequency of use and purity of drugs -- vital factors to come to a holistic conclusion.
Despite the limitations, the annual multi-city study is a good starting point, Goosdell added, saying the EMCDDA is "encouraged by its growing potential for targeting and evaluating localised public health responses and policy initiatives."