Advances in Transformation Mechanism and Increased Adverse Effects of Pharmaceuticals and Personal Care Products During Environmental Geochemistry Processes

Pharmaceuticals and personal care products (PPCPs) are receiving abundant attention as emerging contaminants due to their environmental fate and toxicological properties. They include many products with medical, healthcare or specific purposes for humans and/or animals, and exist ubiquitously in our daily lives. After their broad use and consumption, PPCPs are continuously released into earth's environment with pseudo persistent characteristics. More importantly, these pollutants may undergo transformation during environmental geochemistry processes, leading to the formation of transformation products (TPs) that may pose increased risks to human health and ecosystems. Particularly several TPs have been found to be higher concentrations and increased toxic effects as compared to the original PPCPs. Thus, in this critical review, we analyze the literatures on transformation mechanism of PPCPs during the environmental geochemistry processes, including hydrolysis, photochemical transformation, and biodegradation in water systems. The aquatic toxicity and health effects of PPCPs as well as their TPs are emphasized. Furthermore, the current challenges and recommendations for future research are also pointed out. This review will supply helpful information to better understand the behavior of PPCPs in environmental geochemistry processes from the viewpoint of mechanism, catalyzing a more comprehensive research on the risk assessment and management of PPCPs and their TPs in future.