The fourth edition of 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), carried out in 24 countries ( 23 of the European Union + Turkey), covering 88 cities, including the Portuguese cities Lisbon, Porto and Almada, detected a greater consumption of cocaine in analyses of Wastewater Treatment Plants (WWTP), which has been a “growing trend” since 2016.

Wastewater produced by an estimated population of 55.6 million people was analysed between March and May 2023 to detect traces of five illicit stimulant drugs (cocaine, amphetamines, methamphetamines, MDMA/ecstasy and ketamine), as well as cannabis.

Based on the document, EMCDDA scientific analyst João Pedro Matias explained that increases in cocaine consumption were detected in relation to 2022 (from 265.9 to 512.5 mg/1,000 people/day), a similar trend at a global level in about two thirds of the analyses.

According to the expert, the results point to a continuous increase in the detections of this drug in the wastewater of the cities analysed, a trend that has been observed since the beginning of this type of study in 2011.

Unlike 2022, the methamphetamine situation appears to have stabilised, after an increase that year, data for 2023 shows a decrease in consumption, with no traces of the substance being recorded in Porto or Almada.

Porto also showed a slight increase in MDMA/Ecstasy consumption (from 16.6 to 18.6 mg/1000 people/day), while Lisbon (from 121.8 to 33.1 mg/1000 people/day) and Almada (from 23.6 to 13.2 mg/1000 people/day) showed a decrease when compared to 2022.

However, warns the expert, despite the decrease, MDMA/ecstasy consumption in Lisbon remains similar to European cities with higher amounts of MDMA detected in wastewater analyses.

With regard to cannabis, the most consumed drug throughout the European Union, the three Portuguese cities observed had very similar results, but with divergent trends in relation to the previous year, with an increase in consumption in Porto (from 64.1 to 98.3 mg /1000 people/day) and decreases in Lisbon (from 129.9 to 113.2 mg/1000 people/day) and Almada (from 134 to 102.6 mg/1000 people/day).

Regarding amphetamines, Portuguese cities do not present significant values, concludes the expert.

The director of the EMCDDA, Alexis Goosdeel, highlights in the document's summary that “wastewater analysis now provides an increasingly broader view of the dynamics of drug use and availability and is a powerful tool for increasing preparedness in the face of evolving challenges".