According to current surveys and overdoses data, there is a drug crisis in the USA. Wastewater-based epidemiology (WBE) is an evolving discipline that analyses wastewater samples to detect drugs and metabolites to estimate drug consumption in a certain community. This study demonstrates how drug relative presence could be tracked by testing wastewater, providing real-time results, in different boroughs in New York City throughout 1 year. We developed and fully validated two analytical methods, one for 21 drugs and metabolites, including nicotine, cocaine, amphetamines, opioids and cannabis markers; and another for the normalization factor creatinine. Both methods were performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) using positive electrospray ionization, achieving a limit of quantification of 5-10 ng/L for drugs and metabolites, and 0.01 mg/L for creatinine. These methods were applied to 48 one-time grab wastewater samples collected from six wastewater treatment plants in New York City (Manhattan, The Bronx, Queens and Brooklyn), eight different times throughout 2016, before and after major holidays, including Memorial Day, 4th of July, Labour Day and New Year's. In this study, the drug group normalized concentrations present in the wastewater samples, in decreasing order, were cocaine, nicotine, opioids, cannabis and amphetamines. When looking at individual compounds, the one with the highest normalized concentration was benzoylecgonine (BE), followed by cotinine, morphine and 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH). To estimate community use, these concentrations were multiplied by the corresponding correction factor, and the most present were THCCOOH, followed by BE, cotinine and morphine. When comparing the treatment plants by drug group (nicotine, cocaine, amphetamines, opioids and cannabis), samples collected from The Bronx had the highest normalized concentrations for nicotine, cocaine and opioids; The Bronx and Manhattan for cannabis; and Manhattan and Queens for amphetamines. In most of the cases, no effect due to holiday was observed. This study provides the first snapshot of drug use in New York City and how that changes between key calendar dates employing wastewater analysis.
