Department of Environmental Sciences
Score 2021 latest results on drug use in 6 Slovenian cities based on wastewater epidemiology

Score 2021 latest results on drug use in 6 Slovenian cities based on wastewater epidemiology / 17.03.2022

The European Monitoring Center for Drugs and Drug Addiction (EMCDDA) today published the results of the international survey on the use of illicit drugs SCORE 2021, in which Slovenia was included for the fifth time, thanks to the researchers from the Department of Environmental Science of the Jožef Stefan Institute, led by prof. dr. Ester Heath.

Among Slovenian cities, the records show the highest mass loads of benzoylecgonine (biomarker of cocaine) in Koper, amphetamine and MDMA in Velenje, and methamphetamine and THC-COOH (biomarker THC) in Ljubljana. The average mass loads of biomarkers in Slovenian cities for methamphetamine and MDMA were below the SCORE average for 2021, while the average mass loads of benzoylecgonine in Koper and amphetamine in Velenje were above average. The average mass load of THC-COOH was above the SCORE average in all Slovenian cities. Compared to European and world capitals, Slovenian cities rank in the top half of the participating cities in terms of THC-COOH and benzoylecgonine content, and in the bottom half in terms of other biomarkers. The exception is amphetamine in Velenje. The time trend of drug use is city-specific.

Data on illicit drug use are usually obtained on the basis of population surveys, data on drug seizures, poisonings and hospitalizations. Wastewater-Based Epidemiology (WBE) is an approach used to assess drug use in a target population. It is based on the chemical analysis of untreated wastewater on the content of individual drugs or their metabolic products, i.e. biomarkers. Based on these basic parameters of the treatment plant operation (number of population units, flows, etc.), we can estimate the use of illicit drugs in the population of the catchment area's catchment area on the basis of these data. Compared to classical epidemiological methods, the WBE is a non-invasive and objective approach that allows the monitoring of temporal and spatial patterns of use in near real time by obtaining data on drug use, which requires long-term and frequent measurements.
Over 100 sewage treatment plants participate in SCORE monitoring

The collection of data on the situation in the field of drug use based on wastewater analysis takes place within the annual international monitoring organized by the Sewage Analysis CORe group Europe (SCORE) network in cooperation with the European Monitoring Center for Drugs and Drug Addiction. and Drug Addiction, ECMDDA) since 2011. Measurements include analysis of weekly samples (seven consecutive days) of untreated wastewater for the presence of biomarkers of four stimulant drugs: cocaine (biomarker benzoylecgonine), ecstasy (3,4-methylenedioxymethamphetamine, MDMA), amphetamine amphetamine) and methamphetamine (methamphetamine), in addition to the biomarker tetrahydrocannabinol, THC (11-nor-9-carboxy-THC, THC-COOH). In 2021, 90 sites (110 treatment plants) and 38 laboratories participated in the monitoring.

Researchers from the Department of Environmental Science of the Jožef Stefan Institute, led by prof. dr. Ester Heath joined the SCORE network in 2017 with the analysis of wastewater from the Ljubljana treatment plant. A year later, in addition to Ljubljana, they also included Domžale-Kamnik and Maribor. Since 2019, six Slovenian cities have been included in the monitoring. catchment areas: Ljubljana, Domžale-Kamnik, Maribor, Koper, Novo mesto and Velenje.

Highest contents of benzoylecgonine (biomarker of cocaine) per 1000 population in Koper, amphetamine and MDMA (biomarker of ecstasy) in Velenje and methamphetamine and THC-COOH (biomarker of THC) in Ljubljana

Today, the EMCDDA, in collaboration with SCORE, published the latest information on illicit drug use, based on measurements in 2021. From the results of wastewater analyzes (Annex: SCORE / EMCDDA visualization of data for 2021, EMCDDA website: https: // www. emcdda.europa.eu/publications/html/pods/waste-water-analysis_en) can be summarized as follows:

- among Slovenian cities included in the survey, on average the highest normalized weight loads of benzoylecgonine (cocaine) were determined in Koper (407 mg / day / 1000 population), followed by Ljubljana (365 mg / day / 1000 population), the lowest however, values were determined in Maribor (156 mg / day / 1000 population). With the exception of Koper, all Slovenian cities with average normalized mass loads fell below the average of SCORE monitoring (378 mg / day / 1000 inhabitants).

- among Slovenian cities included in the survey, on average the highest normalized mass loads of MDMA (ecstasy) were determined in Velenje, followed by Ljubljana (both around 8 mg / day / 1000 inhabitants), and the lowest values were determined in Novo mesto (5 mg / day / 1000 population). With average normalized mass loads, Slovenian cities ranked below the average of SCORE monitoring (23 mg / day / 1000 inhabitants).

- among the Slovenian cities included in the survey, on average, the highest normalized mass loads of methamphetamine were determined in Ljubljana (4 mg / day / 1000 inhabitants). In Maribor and Novo mesto, methamphetamine was below the limit of quantification in all wastewater samples. All Slovenian cities ranked well below the SCORE monitoring average (28 mg / day / 1000 population) with average normalized mass loads.

- among the Slovenian cities included in the survey, on average the highest normalized mass loads THC-COOH (THC) were determined in Ljubljana (143 mg / day / 1000 inhabitants), and the lowest in Domžale-Kamnik (67 mg / day / 1000 inhabitants). All Slovenian cities ranked above the average SCORE monitoring (42 mg / day / 1000 population) with average normalized mass loads.

- if the data on mass flows of biomarkers are calculated on the basis of drug use, cocaine and THC are the most widespread drugs among the studied, and the latter is expected to lead in the number of doses.

Time trends
According to SCORE recommendations, at least five consecutive annual measurements are required to forecast time trends in drug use. With the exception of Ljubljana, which has been included in the SCORE survey for five years, we do not have enough data to predict time trends. Nevertheless, the results suggest the following:
- In the observed five-year period, amphetamine and MDMA show a declining trend in use in Ljubljana (with the exception of the extremely high value of MDMA use in 2020). A declining trend is also observed for cocaine, while methamphetamine and THC use are relatively constant.
For other cities that do not meet the criteria of five consecutive measurements for forecasting time trends, we find:
- Maribor: four consecutive measurements show an increase in cocaine and THC use;
- Domžale-Kamnik: in the four-year observation period, we observe a trend of increased cocaine and THC use and a decline in amphetamine use;
- Koper, Novo mesto and Velenje: due to fluctuations in use for the observed period of three years, it is not possible to predict trends in drug use, with the exception of Velenje, where we observed an increase in cocaine use in 2021.
The general estimate of drug use in the year before the epidemic (2019) and in 2020 and 2021 (during the epidemic) shows a decline in most drug use in 2020 (the first year of the epidemic), which in 2021 reached or exceeded pre-epidemic levels (2019) .

Projects
The Jožef Stefan Institute is coordinating a project task entitled: Illicit drugs, alcohol and tobacco: wastewater epidemiology, treatment efficiency and vulnerability of the water system, financed by ARRS and co-financed by five end users (JP VODOVOD KANALIZACIJA SNAGA, doo, JP Domžale-Kamnik, doo, Mariborski vodovod, dd, Public Company-Azienda Pubblica Marjetica Koper, doo and Komunala Novo mesto, doo).

MORE INFORMATION:
https://score-cost.eu/monitoring/
http://www.emcdda.europa.eu/topics/wastewater
http://www.environment.si/en/projects/l1-9191/