Traces of cocaine in wastewater have increased in 50 European cities

A European study of wastewater from 88 cities, published this Wednesday, shows that in more than half (50) traces of cocaine found in wastewater treatment plants show an increase in the use of the drug.

The study “Wastewater analysis and drugs – a European multi-city study”, published by the European group SCORE in collaboration with the European Monitoring Center for Drugs and Drug Addiction (EMCDDA), was carried out in 24 countries (23 European countries). Union + Turkey) and 88 cities, including the Portuguese cities of Lisbon, Porto and Almada, showed an “increasing trend” in cocaine consumption since 2011 in wastewater treatment plant (WWTP) analyses.

For the first time, the study, which analyzed daily wastewater samples for one week from March to May 2023 and to which the Lusa agency had access, presents international data from outside the European Union (EU), such as Brazil. , USA and New Zealand.

Some 55.6 million people were tested for traces of five illicit stimulants (cocaine, amphetamines, methamphetamines, MDMA/ecstasy and ketamine) as well as cannabis.

Along with a steady increase in cocaine detections, the study shows a recent increase in MDMA/ecstasy use, following a mixed picture in previous analysis.

For amphetamines and cannabis, analyzes showed diverging patterns, while for methamphetamines, more than half the cities recorded a decline. While detections varied significantly among the locations studied, it was “important” that all six illicit drugs examined were detected in nearly all participating cities, the study summary said.

Compared to previous studies, differences in drug use habits between large and small cities are smaller.

The main findings of the study show that the amount of cocaine residues in wastewater remained higher in cities in Western and Southern Europe (especially Belgium, the Netherlands and Spain), but traces of cocaine were also found in most cities in Eastern Europe, where there was a slight increase. observable.

“Of the 72 cities that had data for 2022 and 2023, 49 reported an increase, while 13 cities had no change and another 10 reported a decrease. In the United States, usage levels are similar to those in higher-performing European cities,” the document said.

As for methamphetamine, the consumption of which has traditionally been concentrated in the Czech Republic and Slovakia, the substance is now also present in Belgium, eastern Germany, Spain, Cyprus, the Netherlands and Turkey, as well as in several northern European countries (Denmark, Lithuania, Finland and Norway). In the 67 cities with data available for 2022 and 2023, more than half (39) reported a decrease, 15 an increase and 13 a stable situation, while in the rest the values ​​found were very low to negligible, although Some increase was reported. in cities of Central and Southern Europe.

For MDMA, of the 69 cities with data available for the same period, 42 reported an increase in detections (mainly in southern and central Europe), 16 reported a decrease (mainly in northern Europe) and 11 reported stability. situations with the largest number of residues detected. in Belgium, Germany, Spain, France and the Netherlands.

Data for 2023 showed relatively low levels of ketamine in wastewater reported by 49 cities, but with signs of an increase in more than half of them.

For cannabis, the most consumed substance in the EU, the highest loads were found in cities in Western and Southern Europe, especially in the Czech Republic, Spain, the Netherlands and Slovenia, the study said, explaining that different trends were observed in 2023 (20 out of 51 the city reported an increase over 2022, while 15 reported a decrease).

EMCDDA Director Alexis Gusdil emphasizes in the document’s summary that “wastewater monitoring is a valuable leading indicator that provides early warning of emerging health threats and changing trends.”