Toxic footprints: Unveiling phenolic micropollutants of Indian freshwater ecosystems

Abstract

Contaminants of emerging concern such as Bisphenol A (BPA), Triclosan (TCS), Methyl Triclosan (MeTCS) a metabolite of TCS, and Triclocarban (TCC) have raised serious environmental and public health concerns due to widespread use, environmental persistence, and potential to disrupt endocrine functions. Despite growing evidence of adverse effects-including early sexual maturation, reproductive tract lesions, and ecosystem-level disruptions-comprehensive investigations on the occurrence of these phenolic compounds in both water and fish across diverse inland aquatic systems are scarce in India. The lack of a unified dataset capturing the presence of these contaminants in the aquatic environment presents a significant knowledge gap. So, to fill this gap, we carried out an investigation on the spatial distribution of micropollutants in surface water and fish of inland waters such as rivers, reservoirs, floodplains and sewage-fed wetlands across India. BPA was undetected in water and fish samples from the reservoir, sewage-fed and floodplain wetlands except for the fish of river Cauvery where 8.25 % of the samples tested positive. In East Kolkata's sewage-fed wetlands, 83.06 % and 48.41 % of water samples were contaminated with TCS and TCC, respectively. Water from floodplain wetlands (Chaltia and Katiganga) showed no detectable residues, though fish contained substantial levels of TCS (up to 0.69 μg/g), TCC (up to 1.24 μg/g), and MeTCS. In River Cauvery, no residue of targeted compounds was detected in water, but fish flesh showed widespread contamination of TCS, MeTCS and TCC with varying concentrations. The findings are expected to inform risk assessment, pollution management strategies, and policy interventions to protect the aquatic biodiversity and public health.

Keywords: Bisphenol A; Emerging contaminants; Fish; Health risk; Inland water; Triclocarban; Triclosan.