Global occurrence, distribution, and ecological risk assessment of psychopharmaceuticals and illicit drugs in surface water environment: A meta-analysis

Psychopharmaceuticals and illicit drugs (PIDs) in aquatic environments can negatively impact ecosystem and human health. However, data on the sources, distribution, drivers, and risks of PIDs in global surface waters are limited. We compiled a dataset of 331 records spanning 23 PIDs in surface waters and sediments across 100 countries by conducting a systematic review and meta-analysis of 108 studies published between 2005 and 2022. Most PIDs were sewage-derived, as wastewater treatment rarely achieved complete removal. The highest total PID levels were in Ethiopia, Australia, and Armenia, with many highly contaminated samples from low- and middle-income countries with minimal prior monitoring. Socioeconomic factors (population, GDP) and environmental variables (water stress) influenced the distribution of PIDs. 3,4-Methylenedioxy amphetamine hydrochloride (MDA), Delta 9-tetrahydrocannabinol (THC), and 11- Delta 9-hydroxy-tetrahydrocannabinol (THC-OH) posed the greatest ecological risks, especially in Oceania and North America. PIDs in surface waters present risks to aquatic organisms. Our findings elucidate the current status and future directions of PID research in surface waters and provide a scientific foundation for evaluating ecological risks and informing pollution control policies.