Ranking and prioritizing pharmaceuticals in the aquatic environment of China

Pharmaceuticals have become "persistent" pollutants in the aquatic environment, due to their wide usage in daily life and their continuous release into the aquatic environment. Hence, prioritization and ranking lists are required to screen for target compounds as part of risk assessments. A ranking system based on three criteria, such as occurrence, exposure potential and ecological effects, was developed in this study for specific application to China. A total of 100 pharmaceuticals were selected as candidates based on the ranking system and available consumption data. These pharmaceuticals have been previously reported by wastewater treatment plants (WWTPs) in China. 13 pharmaceuticals were classified as priority pharmaceuticals, among which diclofenac, erythromycin, and penicillin G were highly prioritized. Due to their abuse, antibiotics contributed a majority to the priority pharmaceuticals among all therapeutic classes, indicating that antibiotics should be considered based on their behaviors in WWTPs. The pharmaceuticals ranking list achieved good applicability and will help to establish a focus for future monitoring and management of pharmaceuticals. It will also provide an important basis for both ecological risk assessment and pollution control of pharmaceuticals in the aquatic environment.