According to a study by the European Observatory on Drugs and Drug Addiction - referring to the years 2021 and 2022, which analysed wastewater from 104 cities in 20 Member States of the European Union and Turkey – there was "an increase in detections of cocaine and methamphetamine" and analysis of water from Wastewater Treatment Stations (WWTP) manages to provide "an increasingly broad view of the dynamics of drug use and availability”.

Cocaine use

Analysis of wastewater carried out by the European Monitoring Center for Drugs and Drug Addiction (EMCDDA) study shows Portugal alongside Belgium, the Netherlands and Spain as one of the main users of cocaine in Western Europe, but the document considers it "significant" that all six drugs under investigation (cocaine, methamphetamine, amphetamine, MDMA, ketamine and cannabis) were found in almost all participating cities.

With regard to cocaine, increases in consumption were detected in Lisbon and Almada, while there was a stable situation in Porto for 2021. At a global level, the results point to a continuous growth in detections of this drug, a trend that comes to be observed since the beginning of this type of study, in 2016, “despite some fluctuations during the lockdowns related to covid-19”.


The situation of methamphetamines “seems to be evolving”, with traces being detected in more cities, with Lisbon being one of those that last year registered an increase compared to 2021, with no traces of the substance being registered in Porto, according to EMCDDA analyst João Pedro Matias.

Traditionally concentrated in Slovakia, this drug is currently also present in Belgium, eastern Germany, Spain, Cyprus and Turkey and in several countries in northern Europe (such as Denmark, Latvia, Lithuania, Finland and Norway) . Of the 60 cities for which data are available for 2021 and 2022, almost two thirds (39) reported an increase in waste, 15 of them a decrease and six others a stable situation.


Lisbon and Almada also show an increase in MDMA/Ecstasy consumption, while in Porto the data are similar to those of 2021.

The MDMA/Ecstasy consumption trend “is less clear” globally, as of the 62 cities with data for 2021 and 2022, 28 reported an increase in MDMA detections (mainly in southern and central European locations), 27 decreased (mainly in Northern Europe) and seven were in a stable situation. The highest residues of MDMA were found in cities in Belgium, the Netherlands, Spain and Portugal.

Cannabis increase

With regard to cannabis, the most consumed drug in the entire European Union, the three Portuguese cities observed had “slight increases” in consumption compared to 2021, however Portugal is included in the group of cities in western and southern Europe, along with Spain and the Netherlands, where the highest loads of metabolites of this drug (THC-COOH) were recorded.

However, in 2022 divergent trends were observed in the consumption of this substance, with 18 of the 36 cities reporting a decrease since 2021, 15 an increase and five a stable situation.

The study, which analysed wastewater from 54 million people, revealed large differences between cities in the same country, which, according to the Lisbon-based drug observatory, can be explained by their different geographical, social and demographic characteristics (age distribution, universities and existence of nightlife, among others).