project

Drugs of abuse

Expert(s):
Prof. Pim de Voogt PhD, Erik Emke BSc

  • Start date
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  • collaborating partners

Latest results announced for the Amsterdam, Utrecht and Eindhoven sewer water study

In 2015, for the fifth year in a row, a European study into drugs in sewer water was carried out to determine the geographic differences and time trends in drug use amongst citizens. The European Monitoring Centre for Drugs and Drug Addiction – the EMCDDA in Lisbon – today publishes the European Drug Report 2016 containing new results for cocaine, amphetamine, ecstasy, methamphetamine and cannabis measurements. Once again, for amphetamine use the Netherlands is in the Top 5 of the 80 mostly European cities that took part in the study. Pim de Voogt from the Dutch Watercycle Research Institute (KWR) and the University of Amsterdam (UvA), and Erik Emke (KWR) analysed the sewer water of Amsterdam, Utrecht and Eindhoven.

The sewer water study is conducted by the European SCORE network and is part of a long-term study. Results obtained between 2011 and 2014 have been compared with the most recent data from 2015. For one week in March of last year, samples were taken from sewage treatment plants in 80 cities and subjected to chemical analysis. This allowed drug use in a population of more than 35 million people to be analysed. This is the fifth and so far the most extensive study to compare sewer water collected between 2011 and 2015 under a common testing programme in 26 countries.

City drug use analysed in real-time

Chemical analysis of sewer water is rapidly developing into a discipline that can analyse in near-real-time the trend in using drugs and other substances by citizens. De Voogt therefore refers to this sewer epidemiology as a ‘societal mirror’. By sampling the influent of a sewage treatment plant the researchers are able to calculate, on the basis of the concentration of drugs or their conversion products that end up in urine and thus sewer water, the total ‘load’ of drugs in a city. Load is a measure of the number of milligrams of a drug transported to the sewage treatment plant per day per 1000 inhabitants.

Drug use in the Netherlands

Beside the analysis of drug use in the three Dutch cities covered by the EMCDDA report, there are questions on the drug use in smaller municipalities in the Netherlands and the spatial differences over the whole of the Netherlands. KWR will be publishing test results of a pilot in 8 smaller cities for this during this year. This information is not only of relevance for public health, but also for public order and judicial purposes as illegal dumps of illicit drug production can be retrieved in the data.

Proven method, valuable information

According to the EMCDDA, the sewer water study into drug use provides benefits next to the existing national surveys. Testing can be conducted and reports compiled more often and quickly, so spatial and temporal trends can be detected. The number of people sampled via the sewage water is orders of magnitude larger. However, the surveys do yield information on the subgroups using the drugs, information that is not retained via the sewage studies
KWR researcher Pim de Voogt: “We have routinely been using the sewer water method for six years now, in addition to the other drug monitoring methods. The sewer water study has since proven that it generates valuable additional information about trends in the distribution and use of drugs. It is now being used to identify psychoactive substance (designer drugs) that are new to the market and to demonstrate which specific drugs this concerns.”

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Drug use in Amsterdam, Utrecht and Eindhoven

The results from the last five years of sewer water studies (2011-2015) for the use of amphetamine (speed), methamphetamine (crystal meth), cocaine, cannabis and MDMA (ecstasy) in Utrecht, Amsterdam and Eindhoven are as follows:

Figure 1. Amphetamine (speed) loads The Netherlands is in the Top 5 of European countries.
Figure 2. Methamphetamine (crystal meth) loads Virtually no use in the Netherlands; Amsterdam scores as one of the lowest in Europe.

Figure 2. Methamphetamine (crystal meth) loads. Virtually no use in the Netherlands; Amsterdam scores as one of the lowest in Europe.

 

Figure 3. Consumption of pure Cocaine derived from calculated loads of the breakdown product of cocaine Unchanged, high use in Amsterdam. (Top 2 in Europe). Utrecht is showing a gradual reduction in cocaine use between 2011 and 2015. NB. Figure 3 shows the consumption of cocaine, compared to the other four substances for which only the loads are shown. This is because it is only known accurately for cocaine how much of the cocaine conversion product is excreted by the body after cocaine has been consumed. The level of consumption can be calculated back from that. Incidentally, the consumption of cocaine that is shown in Figure 3 concerns the 100% pure substance. The average purity of street cocaine is approximately 50%. This means the figures in the graph have to be multiplied by two in order to obtain the consumption of the amount of cocaine sold on the street or via dealers.

Figure 3. Consumption of pure Cocaine derived from calculated loads of the breakdown product of cocaine. Unchanged, high use in Amsterdam. (Top 2 in Europe). Utrecht is showing a gradual reduction in cocaine use between 2011 and 2015. NB. Figure 3 shows the consumption of cocaine, compared to the other four substances for which only the loads are shown. This is because it is only known accurately for cocaine how much of the cocaine conversion product is excreted by the body after cocaine has been consumed. The level of consumption can be calculated back from that. Incidentally, the consumption of cocaine that is shown in Figure 3 concerns the 100% pure substance. The average purity of street cocaine is approximately 50%. This means the figures in the graph have to be multiplied by two in order to obtain the consumption of the amount of cocaine sold on the street or via dealers.

 

Figure 4. Cannabis loads Together with Switzerland, Spain and France, the Netherlands has the highest use for Europe. Cannabis consumption is particular high in Amsterdam. In 2015, the use in Utrecht and Eindhoven was lower compared to previous years. *No data is available for 2013.

Figure 4. Cannabis loads. Together with Switzerland, Spain and France, the Netherlands has the highest use for Europe. Cannabis consumption is particular high in Amsterdam. In 2015, the use in Utrecht and Eindhoven was lower compared to previous years. *No data is available for 2013.

 

Figure 5. MDMA (ecstasy or XTC) loads The Netherlands is No. 1 in Europe by far for the use of XTC (No. 1, 2 and 4). Between 2011 and 2015 the use in Utrecht has declined but in Amsterdam it has increased. For the first time in four years there was no direct discharge of XTC detected in the sewer water of Eindhoven.

Figure 5. MDMA (ecstasy or XTC) loads. The Netherlands is No. 1 in Europe by far for the use of XTC (No. 1, 2 and 4). Between 2011 and 2015 the use in Utrecht has declined but in Amsterdam it has increased. For the first time in four years there was no direct discharge of XTC detected in the sewer water of Eindhoven.