Sewage analysis as an alternative tool for assessing drug of abuse and new psychoactive substances in Tunisia

• Published in: Forensic science international Vol. 347; p. 111672
• Main Authors: Moslah, Bilel, Smaoui, Omar, Nouioui, Mohamed Anouar, Araoud, Manel, Chaouali, Nadia, Laribi, Meriem, Amira, Dorra, Ben Salah, Nabil, Hedhili, Abderrazek
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.06.2023; Elsevier Limited
• Subjects: Amphetamines; Calibration; Chromatography; Chromatography, Liquid - methods; Cocaine; Consumption; Drug abuse; Drug use; Ecstasy; Epidemiology; Forensic sciences; Humans; Illicit drugs; Illicit Drugs - analysis; Inhabitants; Ions; Liquid chromatography; Liquid chromatography-tandem mass spectrometry; Mass spectrometry; Mass spectroscopy; MDMA; Metabolites; N-Methyl-3,4-methylenedioxyamphetamine; Narcotics; New psychoactive substances; Organic chemistry; Pharmaceuticals; Psychotropic drugs; Residues; Sewage; Sewage analysis; Sewage epidemiology; Sewage treatment plants; Substance Abuse Detection - methods; Substance-Related Disorders - diagnosis; Substance-Related Disorders - epidemiology; Tandem Mass Spectrometry - methods; Tetrahydrocannabinol; THC; Trace levels; Tunisia - epidemiology; Urban wastewater; Wastewater; Wastewater pollution; Wastewater treatment; Wastewater treatment plants; Water Pollutants, Chemical - analysis; Tunisia; France; United States > US; Round Rock Texas; Germany; Urban wastewater; Illicit drugs; Metabolites; Sewage epidemiology; Liquid chromatography-tandem mass spectrometry; New psychoactive substances; Inhabitants
• ISSN: 0379-0738; 1872-6283
• DOI: 10.1016/j.forsciint.2023.111672

Many studies attest to the pollution of wastewaters by organic molecules including drug of abuse (DAs) residues and new psychoactive substances (NPS) at trace levels. The occurrence of these emerging micropollutants in influent wastewaters (IWW) from three Tunisian Wastewater Treatment Plants (WWTPs) was assessed. Influent wastewater composite samples (24 h) were collected over 7 consecutive days in November 2019. The determination and quantification of 11 drug of abuse or their metabolites was performed by the application of an optimized multi-residue method liquid chromatography tandem mass spectrometry (LC–MS/MS). MDMA, THC and the cocaine metabolite benzoyl ecgonine were the most detected substances across the three investigated sewage plants. A new wastewater-based epidemiology (WBE) approach was applied in this study to estimate illicit drug consumption. This innovative approach was used to calculate and to assess collective drug consumption of illicit drug at a community level, based on the concentration of selected illicit substances and their major metabolites in influent wastewater. The average MDMA consumption found in the selected cities ranged between 35,8–1531,1 mg day− 1/1000 inhabitants and increased during the weekends. Cocaine consumption varied from 24.5 to 179.8 mg day− 1/1000 inhabitants. Complementary qualitative investigation of new psychoactive substances was monitored for the first time for an African country, examining the occurrence of 33 NPS in wastewaters samples. Out of 33 totals screened NPS across all sampling sites, 16 were tentatively identified with this approach. The 16 detected NPS covered most of the representative and used molecules of different NPS classes; including synthetic opioids, synthetic cathinones, amphetamines derivatives and synthetic cannabinoids. •A reliable SPE-LC-MS/MS method for the determination of 11 drug of abuse or their metabolites in wastewater was performed.•MDMA, THC and the cocaine metabolite benzoyl ecgonine were the most detected substances across the three sewage plants.•A new wastewater-based epidemiology approach was applied in this study to provide an estimate of illicit drug consumption.•The surge in MDMA consumption mainly during the weekends.•Complementary qualitative investigation of 33 NPS was monitored for the first time for an African country.