Antibiotics, analgesics, NSAIDs, beta-blockers, angiotensin receptor blockers, and other pharmaceutically active compounds in Indian rivers: Occurrence, sources, ecotoxicological risk, and antimicrobial resistance (AMR)

The occurrence of pharmaceutically active compounds (PhACs) in surface and groundwater is increasingly being recognized as an emerging environmental and health concern due to their potential impacts on aquatic biodiversity and their role in promoting antimicrobial resistance (AMR). This study investigates the distribution, sources, and risk assessment of 24 PhACs from 10 categories, including analgesics, antibiotics, nonsteroidal anti-inflammatory drugs, beta blockers, angiotensin receptor blockers, and antidepressants in surface water and groundwater across seven Indian rivers along their urban, suburban, and rural transects using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Higher mean caffeine levels (~5 μg/L) suggest the presence of untreated wastewater from open discharges along the urban transect. The dominant pharmaceutical categories in urban transect were analgesics and angiotensin receptor blockers, with mean concentrations of 2.6 μg/L and 1.4 μg/L, respectively. Among the antibiotics group, erythromycin was the dominant one. Principal component analysis (PCA) and correlation analysis with dissolved organic carbon (DOC) identified untreated domestic sewage, pharmaceutical industrial discharges, and urban wastewater inputs as the major sources of PhACs, with stronger DOC–PhACs coupling observed in urban transect. Ecotoxicological risk assessment indicated that telmisartan poses potential risks to fish and daphnids in urban sites. Estimated antimicrobial resistance revealed elevated risk quotients (RQ AMR > 1) for azithromycin, erythromycin, sulfamethoxazole, and trimethoprim in the Musi River and for trimethoprim in the Cooum River, indicating potential for public health risks.