A Systematic Review on Distribution and Ecological Risk Assessment for Chiral Pharmaceuticals in Environmental Compartments

Abstract

Chiral pharmaceuticals are an important class of environmental pollutants. Monitoring studies have shown the non-racemic presence of these contaminants in wastewater, sludge and the receiving environment. This review describes the role of chirality in the environment, especially the distribution and toxicities of enantiomers of chiral pharmaceuticals. In the first part, a systematic overview of their distribution in various environmental matrices and the main application of chiral signatures as chemical markers of water contamination are discussed. Available studies mainly focus on four drug groups including NSAIDs, β-blockers, antidepressants and illicit drugs due to their environmental pseudopersistence and ecotoxicological effects. In the second part, a summary of the enantiospecific toxicity data reported for chiral pharmaceuticals is provided. These data are of high value to improve the accuracy of environmental risk assessments in future works. Enantioselective toxicity towards aquatic organisms have been established for ten out of 36 chiral pharmaceuticals measured and detected in wastewater or surface water samples. Their enantioselective biodegradation and ecotoxicity make the risk assessment process highly recommended. The results provided in this review work support the need for new approaches to more accurately determine the toxicological risks associated to the stereochemistry of environmental contaminants.