Occurrence of High Levels of Fluoroquinolones in Aquatic Environment due to Effluent Discharges from Bulk Drug Manufacturers

Improper disposal of effluents from bulk drug manufacturing units creates a pathway for antibiotics to enter the aquatic environment. This study investigated the presence and distribution of antibiotics belonging to fluoroquinolone group (ciprofloxacin, lomefloxacin, ofloxacin, norflaxacin, enrofloxacin, pefloxacin, and difloxacin) in the aquatic environment of the Musi River in India. Results showed that fluoroquinolones were present in exceptionally high concentrations in the river. Ciprofloxacin, ofloxacin, and norfloxacin were frequently detected with the highest concentrations, up to 5,015, 542.4, and 251 μg/L, respectively. Due to the impact of effluents from bulk drug manufacturing units, antibiotic concentration was observed to be several folds higher than the usual range of its occurrence around the world. Positive correlation was observed between the concentration of fluoroquinolones in the water and sediment samples collected along the river due to sorption affinity of fluoroquinolones onto solids. The findings from the present study call for an increased focus on the development of regulatory specification and safe disposal practices of bulk drug manufacturing units into surface water.