Amsterdam is the new European leader in cannabis and MDMA use. In the capital, drug use increased considerably last year, while in Rotterdam drug use fell compared to 2023. In Amsterdam, most ketamine is also used, Eindhoven is in second place.
This is the conclusion of comparative research into drug residues in sewage, which was published on Wednesday by the European drug agency Euda. Last year other European cities led these lists. Then most of the cocaine, MDMA and Ketamine were used in Antwerp and the most cannabis in Rotterdam.
The figures are based on samples from sewage treatment plants that were taken for a week in the spring of 2024. 128 European cities participated in 26 different countries. From six drugs – amphetamine (speed), cannabis, cocaine, ketamine, mdma (the active substance in XTC) and methamphetamine (Crystal Meth) – the concentration in the waste water per thousand inhabitants is then calculated. In this way cities of different population scope can be compared.
This year, six Dutch cities took part in the investigation: Amsterdam, Rotterdam, Utrecht, Eindhoven, Groningen and Zwolle. Leeuwarden, which stood out last year because of the high concentrations of cocaine, speed and cannabis in sewage, was missing this year. Participation in the study is only possible if municipalities themselves apply for measurements at the Water Research Institute KWR and give permission to share the results with the Euda.
The measurements in Eindhoven are not complete, due to drug dumps, the concentrations of MDMA and MET not only came from drug users but also from drug waste.
Cannabis
In many European cities, the use of stimulating agents such as MDMA, Cocaine and Speed has increased again, reports Euda. Amsterdam stands head and shoulders above the other cities with regard to MDMA use: the measured concentrations are twice as high as in the numbers two and three (Antwerp and Rotterdam). Utrecht and Groningen are also in the top 5.
The use of cannabis generally declined slightly in Europe in 2024. But not in Amsterdam, there are the cannabis concentrations in sewage water even 60 percent higher than in 2023. That is striking, says Thomas ter Laak, who was involved in the sewage measurements as a researcher on behalf of the KWR. “A drug like MDMA is mainly used recreational, so that the sample can lead to greater variation between different years. But with Cannabis you don’t really expect that, which is used by many people every day.”
After Amsterdam, Groningen is the second European city in terms of cannabis use; Because the city did not participate in the investigation last year, it is unclear whether this is an increase.
The differences between these two cities are also not that great that there is a clear number one or two, says Ter Laak. “We also measure in a city for more than one week and then we see that measurements from different weeks can differ 10 to 20 percent from each other.” The measurements are especially suitable for trends to discover trends over a longer period.
Also during the week Ketamine
Where the use of cocaine has generally increased in Europe, this does not apply to Dutch cities. In Rotterdam and Utrecht even slightly lower concentrations were found than in 2023. The Ketamine concentrations were first published for all participating Dutch cities, and two Dutch cities are immediately at the top of the list: Amsterdam and Eindhoven.
Trimbos researcher Laura Smit-Rigter strikes the ketamine figures that the Ketamine concentrations do not show a peak at the weekend, as is the case with MDMA. “That could indicate that it is also consumed at home parties during the week,” says Smit-Rigter. She also keeps an eye on the use of Crystal Meth in Amsterdam. That concentration is relatively low compared to the Czech cities that dominate the top. “But we do see a clear rising trend in recent years. I expect that there is a small group that uses this, but with a higher frequency.”
There are major differences in drug use between Dutch cities. For example, relatively much speed is used in Zwolle. To be able to explain these types of local patterns, the Trimbos does additional research. “The sewage measurements give a picture of the total consumption of drugs,” says Smit-Rigter. “For a more complete picture about the user, we conduct research based on questionnaires, the residue of found spraying and our test service for drugs. I am curious if we will see the same trends there this year.”
This story was created in collaboration with the European Urban Journalism Network.
Rotterdam is a European leader in cannabis use-many Dutch cities in top 5, also with cocaine use