Pharmaceutical Contaminants in Indian Freshwaters: Toxicological Pathways, Ecological Risks, and Remediation Approaches

Pharmaceutical pollution of freshwater ecosystems is an emerging environmental and public-health issue in India. The high drug consumption in the country, along with the presence of concentrated manufacturing hubs, inadequate wastewater treatment, and weak monitoring systems, is leading to rising pollutant release. This review summarizes the existing evidence on pharmaceutical contaminants in Indian freshwaters with the focus on classes of pollutants, sources of contamination, environmental fate, toxicological pathways, ecological risks and remediation strategies. Antibiotics, non-steroidal anti-inflammatory drugs, stimulants and anticonvulsants are identified in the review as priority contaminant groups owing to their frequent detection, high use volume, environmental persistence and ecotoxicological relevance. These residues can enter freshwater systems through discharges from pharmaceutical manufacturing, hospital effluents, domestic wastewater, livestock runoff and agricultural pathways. Their persistence is due to their physicochemical properties, adsorption to sediment, incomplete biodegradation and limited removal in conventional wastewater treatment plants. Toxicological evidence points to risks of selection for antibiotic resistance, endocrine disruption, neurotoxicity, oxidative stress, reproductive impairment, genotoxicity and bioaccumulation in aquatic food webs. The review also covers microbial degradation, phytoremediation, constructed wetlands and advanced oxidation processes as remediation options and points out that the choice of technology should be context specific for industrial, municipal and natural water systems. This review offers a novel India-centric synthesis that links pharmaceutical production, consumption, environmental occurrence, ecological effects and remediation feasibility into an integrated framework for monitoring, policy reform and future research.