The drug residue in sewage analysis conducted by the National Institute for Health Development (Tervise Arengu Instituut) shows that the most consumed substances in the Tallinn area are cannabis, amphetamine, and cocaine.
Differences between days of the week are most common in consumption of MDMA, cocaine, and ethanol, which are mostly consumed on weekends. This refers to the substances being used at entertainment venues and events. The differences in consumption of amphetamine between week days was still smaller than that of cocaine and MDMA.
Katri Abel-Ollo, researcher of the Centre for Prevention of Drug Addiction and Infectious Diseases, said: "After the availability of illegal fentanyl reduced in Estonia, amphetamine has been the most consumed injection drug, which explains the comparatively constant amounts of daily consumption.
The consumption of cannabis was similar on all weekdays, which for one is due to the wide-spread consumption of the drug in Estonia, but also because THC COOH metabolite is detectable in urine for a long time.
The samples were taken from the main pump of AS Tallinn Vesi's sewage treatment plant on March 11-17 2019.
As for both legal and illegal substance residue in sewage, the analysis does not differentiate the consumption of Tallinn locals, domestic tourists, and foreign tourists. There are large hotels, nightlife and entertainment venues in Tallinn that are visited by many other people not from the Tallinn area.
Abel-Ollo said: "Tourism and entertainment venues affect substance consumption rates, but mostly that of legal substances, like alcohol."
Wastewater analyses, using a Europe-wide SCORE network, are conducted in more than 40 European cities.
Wastewater analysis in Tallinn was performed by the Estonian Forensic Science Institute (Eesti Kohtuekspertiisi Instituut). Although the methods have certain limitations and a factor of uncertainty, the value of research comes from fixating base levels of legal and illegal substance consumption.
The analysis planned to be annual and will likely expand to other cities.
Editor: Kristjan Kallaste