The European Medicines Agency says there is less of the main active ingredient in cannabis in the wastewater samples taken from 128 European cities, but more of another active ingredient, a stimulant.
A new study of wastewater from 128 European cities shows that Cannabis use is decreasing while stimulant drug use like cocaine and MDMA (ecstasy) is increasing.
The study, done by the European group SCORE with EUDA (European Medicines Agency), gives a lot of information about drug use in Europe. They used wastewater samples to find different compounds. The study found that cannabis use is decreasing.
The project looked at wastewater from 128 European cities in 26 countries (24 in the EU as well as Turkey and Norway) to learn about the drug use of the people living in these cities.
The study looked at samples of wastewater every day from areas where wastewater treatment plants are located. This study was done from March to May of 2024. They looked for five stimulant drugs: amphetamine, cocaine, methamphetamine, MDMA/ecstasy, and ketamine. They also looked for cannabis.
According to the European Medicines Agency (EMA), scientists in many different fields are studying this. These fields include analytical chemistry, physiology, biochemistry, wastewater engineering, spatial and statistical epidemiology, and the epidemiology of traditional substances.
Although cannabis is still the most popular drug in the European Union, recent data show a decrease in the amount of cannabis in many of the cities that were studied. But this change was not the same in all cities. Some cities saw more cannabis, while others saw a lot less. The cities with the highest levels of cannabis were in the Czech Republic, Spain, the Netherlands, and Slovenia.
The decrease in residue levels could be due to changes in laws, changes in what people like to buy, or the influence of new legal markets in European countries, which might change how people use drugs.
Increase in stimulant drugs
While fewer people are using cannabis, the same is not true for cocaine and ecstasy (MDMA). Cocaine was found in high concentrations in wastewater in cities in Western and Southern Europe, particularly in Belgium, the Netherlands, and Spain. It was also found in almost all of the Eastern European cities included in the study, which suggests that people are using more cocaine and ecstasy (MDMA).
MDMA (also known as ecstasy) has increased a lot in some areas, particularly in cities in Belgium, Germany, France and the Netherlands. MDMA was first found in the Czech Republic and Slovakia, but it is now also found in countries like Germany, Spain, Cyprus, the Netherlands, and Turkey.
Portugal follows European trends.
In Portugal, the cities of Porto, Lisbon, and Almada took part in the testing and analysis. There was a big increase in cocaine levels in wastewater in Porto. The levels went up from 265.9 milligrams per 1,000 people per day to 512.5 milligrams per 1,000 people per day compared to the previous year. There were also increases in Lisbon and Almada, but not as high. As for cannabis, there was no change in cannabis waste in Lisbon and Almada, but there was a slight decrease in Porto.
Alexis Goosdeel of the European Medicines Agency (EMA) said that wastewater analysis is an effective way to spot new drug use patterns. He said that this kind of monitoring lets them see changes in how people are using drugs and how they buy them. This helps authorities know how to respond quickly.
The study results highlight the need for ongoing monitoring of drug use trends in Europe, especially as laws about cannabis change and new psychoactive substances become more available.
Since 2011, the European group SCORE has been checking wastewater for drugs. In 2011, 19 cities in 10 countries took part and looked for four stimulant drugs. Since then, 76 cities have taken part in at least five annual wastewater monitoring campaigns to study trends over time.