New results European sewer water analysis

Determining geographical differences and time trends

The objective of the SCORE study is to determine the geographic differences and time trends in drug use in large European cities. This is the second and, to date, the most extensive study which permits the comparison of sewer water from different countries, collected over several years (2011-2014) and using a common protocol.

Chemical analysis of sewer water is rapidly developing into a discipline that can analyse in near-real-time drug use trends among an entire urban population. By sampling at well-defined point sources, such as the influent of a wastewater treatment plant (WWTP), the researchers are able to calculate the city’s total drug load, based on the concentration of drugs or their transformation products – which are created in the body following consumption – excreted in urine.

Sewer water analysis 2014

In April 2014, in more than 50 European, Canadian and Australian cities, sewage plant water samples were collected and analysed daily for a period of week. The results were compared with data from studies carried out in 2011, 2012 and 2013. The sewage water of approximately 29 million people was analysed for the presence of amphetamine, cannabis, cocaine, ecstasy and methamphetamine.

The results present a clear picture of drug use in the cities. They also highlight some remarkable differences:

• Trace levels of cocaine were higher in cities in the west and south of Europe than in those in the north and east.
• Ecstasy use is highest in the Netherlands, Norway, England, Australia (included since 2014) and Denmark (included since 2014).
• Amphetamine use is pretty well the same throughout Europe, with outliers in the north and north-west.
• Cannabis consumption is high in France, the Netherlands, Spain, England and Belgium. Methamphetamine use is generally quite low; previously it was limited to the Czech Republic, Slovakia and Scandinavia, but it is now also apparent in Australia.
• The two Canadian cities had average or below average scores for all five drugs.

Drug use in the Netherlands is quite stable

In the Dutch cities, the consumption levels were relatively high for cocaine, amphetamine and ecstasy; the Netherlands also ranks in the top-3 in cannabis use. The consumption of these drugs has remained quite stable over 2011-2014, with no clear peaks or lows. Nonetheless, direct discharges of amphetamine and ecstasy have been detected in the sewers in Eindhoven – sometimes kilograms per week.