Amsterdam’s waste water has more MDMA and cannabis in it than any other European city and the city also scores highly for cocaine, according to research by European drugs agency EUDA.

Last year, samples of waste water from 128 European cities in 28 countries were tested for six different classes of drugs. Amsterdam topped the list for traces of MDMA, followed by Rotterdam and Utrecht, and also led the European list for cannabis and ketamine.

The Dutch capital was also second to Antwerp in terms of cocaine traces.

The loads of the different stimulant drugs detected in waste water varied considerably across study locations, although all illicit drugs investigated were found in almost every city that participated, the EUDA said.

The waste water analysis suggests cocaine use remains highest in western and southern European cities, in particular in cities in Belgium, the Netherlands and Spain.

The highest loads of amphetamines were also found in cities in Sweden, Germany, Norway, Belgium and the Netherlands.