Illicit Drugs in Wastewater Treatment Plants A case study: Rio de Janeiro, Brazil

Intake of illicit drugs should be expressed not merely for the reason of the public health aspects but also in an environmental context concerning the contamination of surface waters. Wastewater-based epidemiology consists in acquiring relevant information about the standard of living and in population health status athwart the investigation of wastewater samples collected at the influent of a wastewater treatment plant (WWTP). This method has been applied to the examination on samples from 4 WWTPs situated in Rio de Janeiro Municipality, Brazil, to investigate the presence of illicit drugs and their metabolites. These included cocaine (COC), benzoylecgonine (BE, cocaine metabolite), amphetamine (AMP), methamphetamine (METH), and 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH, THC metabolite). Concentrations of COC and its main metabolite BE ranged from 201.3 to 2751.5 ng/L and from 630.7 to 5849.2 ng/L, respectively. Amphetamine-like stimulants ranged from 21.7 to 110.0 ng/L for AMP, and from 55.3 ng/L to 477.4 ng/L for METH. THC-COOH ranged from 188.8 to 940.2ng/L. The concentrations found, besides being noteworthy to public health, may likely have important repercussion influence at the functioning of the environment. It is important to detach that COC and amphetamines (including metabolites as well) have potent pharmacological activities and their incidence as multifarious assortments in the ecosystem must hurt aquatic organisms and, consequently, in human health. However, unfortunately, there is no current regulation demanding the determination of the occurrence of these pollutants at the environment. In conclusion, investigates on the spreading configuration of these illicit drugs and their potentially harmful impact on our environment needs immediate attention and regulatory limits.