Illicit drug use in Reykjavik by wastewater-based epidemiology

Estimation of illicit drug use on a community level by wastewater-based epidemiology (WBE) is both an objective and reliable way to establish near real-time results. Wastewater samples were collected at eleven timepoints in Reykjavik from 2017 to 2020. The use of commonly abused illicit drugs in Iceland (amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), cocaine, and cannabis) was estimated. Solid phase extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry was used for analysis. Estimated amphetamine and methamphetamine use showed signs of an increase from 2017 to 2020 with amphetamine being the dominant stimulant on the market. MDMA use remained stable from 2017 to 2020. Results showed a large increase in cocaine use from 2017 to 2019 but interestingly, a marked decrease in 2020 during the COVID-19 pandemic. Cannabis use was stable from 2017 to 2019 but showed signs of an increase during the pandemic in 2020. Results by WBE corresponded with data based on two other indicators of drug use, seizure data and driving under the influence cases. Both temporal and spatial trends in illicit drug use were successfully estimated by using WBE, complimenting other indicators which provided a comprehensive picture of drug abuse in Reykjavik. [Display omitted] •First comparison of illicit drug use in Reykjavik by wastewater analysis with other indicators.•Wastewater-based epidemiology was used to estimate cannabis use in Reykjavik for the first time.•Results revealed increased use of cocaine and amphetamine from 2017 to 2019.•Changes in patterns of drug use were observed during the COVID-19 pandemic.•Comparison between three indicators of illicit drug use showed corresponding results.