Fluoroquinolones as Environmental Contaminants: Occurrence, Fate, and Phytotoxicological Implications

Fluoroquinolones (FQs) are among the most widely used broad-spectrum antibiotics worldwide, valued for their efficacy against both Gram-positive and Gram-negative bacteria. However, their persistence in the environment has raised significant ecological concerns. Due to incomplete absorption and metabolic transformation in humans and animals, large quantities of FQs are excreted unchanged and subsequently enter aquatic and terrestrial ecosystems via wastewater, agricultural runoff, and biosolids application. This review synthesizes current evidence on the environmental fate of FQs, their phytotoxic effects on aquatic and terrestrial plants, and the potential of phytoremediation as a mitigation strategy. A systematic literature search was conducted for studies published between 2014 and 2025 using major scientific databases, including PubMed, ScienceDirect, Web of Science, and Scopus, to ensure comprehensive coverage of the relevant literature. Studies consistently demonstrate that FQs inhibit plant growth, reduce photosynthetic efficiency, and induce oxidative stress in a dose-dependent manner. Furthermore, FQs promote the dissemination of antibiotic resistance genes in microbial communities, posing an indirect but serious threat to human health. The review also highlights knowledge gaps and areas requiring further research, particularly regarding long-term ecological consequences and the optimization of phytoremediation systems.