Wastewater treatment plants: assessment of illicit drug consumption in west zone, Rio de Janeiro

Abstract

Objective: To estimate the consumption of illicit drugs [amphetamine (AMP), methamphetamine (METH), 3,4-methylenedioxymethamphetamine (MDMA), cannabis (THC-COOH) and cocaine (COC)]. Methods: Composite samples (24 hours) of effluents from 3 wastewater treatment plants (WWTP) (Deodoro, Santa Cruz, Sepetiba), located in the west zone, Rio de Janeiro, Brazil, were collected in 2019 and later analysed with the technique of wastewater-based epidemiology (WBE). Results: The concentrations of COC and its BE, Nor-BE and CE metabolites, ranged from 36 to 601ng/L; 100 to 889ng/L; 19.9 ng/L and 4.68 ng/L, respectively. Amphetamine-like stimulants ranged from 105ng/L for AMP, 28ng/L to 1674ng/L for METH and 4.21ng/L for MDMA. THC-COOH ranged from 112 to 178ng/L and the OH-THC metabolite of 3.7ng/L. Regarding data on average consumption of illicit drugs between 15 and 64 years (mg/day/1000 inhab), only AMP was detected at WWTP Deodoro (41.8 mg/day/1000 inhab), in terms of cannabis (marijuana) and cocaine, all WWTP were positive. Conclusion: Relevant differences were observed in the detection and consumption of the studied drugs, emphasizing that drug use in the studied area is not homogeneous, but raises concerns about the possible impacts on public health.