Wastewater studies of drug residues in Tallinn and Pärnu during the second wave of the coronavirus pandemic in fall 2020 indicate widespread use of both legal and illegal drugs.
The results of the Tallinn study are comparable to the results of the 2019 wastewater study, based on which it can be stated that despite the restrictions and the decrease in tourism, drug use did not decrease significantly in 2020, but rather increased for some substances.
As in 2019, the most common drugs in the Tallinn area were cannabis, amphetamine and cocaine. These were followed by methamphetamine and MDMA, the use of which had increased dramatically compared to a year earlier.
"We also compared substance use by day of the week - similarly to the previous year, the differences were most pronounced for MDMA, cocaine and ethanol. These three substances are mostly used on weekends, from which it can be concluded that some of them are used in the context of entertainment and relaxation, and there is reason to believe that, despite the restrictions arising from the coronavirus pandemic, private parties and gatherings still took place," Katri Abel-Ollo, researcher at the National Institute for Health Development's center for the prevention of drug use and infectious diseases, said.
The concentration of cannabis in wastewater had increased slightly compared to 2019, but not significantly. Fluctuations by day of the week are difficult to estimate for cannabis because cannabis use residue (THC COOH) is detectable in urine for a long time.
Residues of alcohol and nicotine consumption were significantly higher in wastewater compared to illegal substances. Compared to the 2019 survey, there was a 26 percent decrease regarding alcohol, and the nicotine content in wastewater remained relatively the same.
However, when it comes to alcohol and nicotine use, it is important to keep in mind that in the pandemic fall of 2020, there were no foreign tourists in Tallinn in addition to the local population. While the effect of restricting entertainment and the lack of foreign tourists can be assumed in the case of reduced alcohol consumption, the relatively similar level of nicotine use compared to 2019 indicates a higher use of tobacco products by the local population.
The most common drugs in the wastewater of Pärnu were cannabis, cocaine and amphetamine, followed by methamphetamine. The amounts of drug residues in Parnu wastewater were several times smaller than in Tallinn.
"It was surprising to find a small amount of methamphetamine, which was previously found in small quantities on the drug market, also in Pärnu wastewater because the use of this substance is associated with injecting drugs and entertainment events, which were restricted during the study," Abel-Ollo said.
The relatively high concentration of methamphetamine residues in the wastewater of both Tallinn and Pärnu shows the change in the Estonian drug market in 2020 and at the same time illustrates the ability of the wastewater survey methodology to provide an objective overview of what is happening in the market. The higher prevalence of methamphetamine in Estonia is also confirmed by the results of the analysis of the Estonian Forensic Science Institute for drugs seized in 2020.
In the fall of 2020, a wastewater survey of drug residues was conducted in Tallinn and Pärnu. Metabolic residues of drugs, alcohol and tobacco were analyzed from the wastewater of both regions. Drug residues that have entered the wastewater without passing through the human body do not affect the results of the analysis.
The National Institute for Health Development is the coordinator, initiator and funder of the wastewater study of drug residues. The cooperation partners of the study in collecting water samples were the wastewater treatment plant of AS Tallinna Vesi and AS Pärnu Vesi. The Estonian Forensic Science Institute is the National Institute for Health Development's cooperation partner in developing the analysis model and analyzing the wastewater samples.
The study was conducted for the second time in Estonia with this methodology. The study is based on the pan-European SCORE protocol. The first similar wastewater study was conducted as a pilot project in 2019 in Tallinn. In the fall of 2020, in addition to Tallinn, the city of Parnu was included in the study. In both cities, the substances studied were the same. Wastewater samples were collected in Tallinn over the period September 15-22 and in Parnu from October 19 to 26. In Estonia, there were restrictions on nightlife during this period, but to some extent public entertainment still worked. In the case of Parnu, it is also important to mention that the study period fell on the fall school break in Estonia and its results illustrate the use of narcotic drugs by domestic tourists in addition to the local population.
Editor: Helen Wright