Evaluation of pharmaceutical abuse and illicit drug use in South Korea by wastewater-based epidemiology

Drug abuse trends in South Korea were assessed by estimating the consumption rates of drugs that may be abused or misused by performing wastewater-based drug epidemiology. Of the 29 target compounds, 10 were found in samples from three wastewater treatment plants. Ephedrine had the highest mean estimated consumption rate, 574.1 mg d(-1)(1000 people)(-1). The anti-obesity drugs phendimetrazine and phentermine had the second and fifth highest mean estimated consumption rates, 182.9 and 113.1 mg d(-1)(1000 people)(-1), respectively. The zolpidem consumption rate was 65.8 mg d(-1)(1000 people)(-1). Methamphetamine was the only illicit drug detected in wastewater, and the estimated consumption rates (14.9-28.6 mg d(-1)(1000 people)(-1)) were similar to consumption rates found in previous Korean studies (not detected to 45.8 mg d(-1)(1000 people)(-1)). The mean estimated meperidine and cis-tramadol (opioid) consumption rates were 120 and 27.5 mg d(-1)(1000 people)(-1), respectively, and were 8.2 and 1.7 times higher, respectively, than the consumption rates found in 2013. Methylphenidate was detected in the influent and effluent samples at mean concentrations of 2.7 and 2.6 ng L-1, respectively, but the methylphenidate consumption rate could not be estimated because of the low excretion rate for humans (< 1%).