Evaluation of the occurrence of psychotropic drugs in urban sewage and the abuse during the COVID-19 epidemic period in a city of Guangdong

ABSTRACT

Wastewater-based epidemiology was applied to study the impact of the COVID-19 in 2020 on occurrence and consumption of methamphetamine and ketamine before, during, and after the outbreak in a city of Guangdong province. To estimate the total consumption during the outbreak, mobile data of the city was used to study the dynamics of the population in the towns and districts of the city. The concept of composite population was brought about for the first time and calculated to estimate total drug consumptions of each towns or districts. The population during the outbreak decreased by about 45% relative to before the outbreak. The total consumptions of the two drugs declined by about 75% during the outbreak relative to before the outbreak. However, the decrease to this extent rather implies the persistence of abuse of the two drugs, given the extremely strict control measures. The consumptions of the two drugs were found to decrease by approximately 50% relative to before the outbreak. The consumptions of the drugs rebounded to the level before the outbreak, further demonstrating the persistence of the abuse. © 2021, Editorial Board of China Environmental Science. All right reserved.