Assessment of ecological risks posed by veterinary antibiotics in European aquatic environments: A comprehensive review and analysis

The extensive use of antibiotics in human and veterinary medicine has led to the emergence of antibiotic contaminants in the environment, posing significant risks to ecosystems and public health. This contamination arises from the persistence of antibiotics in aquatic environments, particularly in aquifer systems, where they contribute to the growing threat of antibiotic resistance. Despite increasing research, the understanding of the ecological and human health implications of these contaminants remains incomplete. Since these compounds are only partially removed by conventional wastewater treatment plants (WWTPs), they are continuously released into the environment. Antibiotics enter the environment mainly through human and animal excretions, improper drug disposal, wastewater treatment plants, and waste streams from antibiotic production. Recent research has focused on antibiotic metabolites and transformation products, which can affect aquatic ecosystems and the food chain, posing long-term risks to human health. This critical review provides a comprehensive analysis of the risk assessment of veterinary antibiotics (VAs) in European aquatic environments, where VAs concentrations ranging from micrograms to milligrams per liter. By examining toxicity data from freshwater and saltwater species, the study evaluates acute and chronic effects across different antibiotic classes. The review also assesses the sensitivity of various taxonomic groups and species to different antibiotics, providing insights into potential ecological risks. Species sensitivity distributions and hazard concentrations affecting a given percentage of species are calculated to assess the overall ecological risk. The findings reveal varying proportions of toxicity data across antibiotic classes, with Aminoglycosides, β-lactams, Fluoroquinolones, Macrolides, and Tetracyclines classes demonstrating higher toxicity levels than others towards certain cyanobacteria and chlorophyta species. Macrolides and Fluoroquinolones emerge as particularly concerning due to their high toxicological risks across various aquatic environments. The analysis underscores the urgent need for further research to fill knowledge gaps and develop effective strategies to mitigate the harmful effects of VAs on aquatic ecosystems and human health.