Assessing illicit drugs in wastewater: a pilot study in Mexico

Objective. Monitor drug use through wastewater metabolite measurement. Materials and methods.Wastewater samples were obtained from 31 wastewater treatment plants and 95 sites with specific populations (38 schools, 42 units of addiction treatment and 15 penitentiaries). Using ultra high liquid chromatography, we measured nine metabolites from six drugs. Results. Eight out of nine drug metabolites were identified in the samples. Marijuana (THC-COOH), cocaine (benzoylecgonine) and methamphetamine were identified in schools, centers of addiction treatment and penitentiaries. Nuevo Laredo, Culiacan and Torreon had the highest consumption of cocaine, marijuana, amphetamine and methamphetamine. Conclusions. Monitoring drug use through wastewater is feasible in Mexico and could constitute a surveillance system to identify changes in the time.