Integrative Analysis of Seasonal Bioaccumulation Patterns and Toxicological Risk Indices in Freshwater Fish Species of Vembanad Backwaters: Implications for Environmental and Public Health

Abstract

The present study investigates the bioaccumulation of heavy metals in commercially and ecologically important fish species inhabiting the Vembanad Backwater System (VBS), a Ramsar site of high ecological value on the southwest coast of India. A total of 15 fish species were analyzed for six heavy metals (Cd, Cr, Cu, Pb, Zn, and Ni) across three distinct seasons—pre-monsoon, monsoon, and post-monsoon. Concentrations were evaluated using ICP-MS, and the data were statistically analyzed using one-way ANOVA to assess seasonal and interspecific variations. Results indicated significant spatiotemporal variability in metal accumulation patterns. Health risk assessments were conducted using Metal Pollution Index (MPI), Target Hazard Quotient (THQ), and Carcinogenic Risk (CR), revealing potential non-carcinogenic and carcinogenic risks in certain species and regions. The study emphasizes the importance of integrated environmental monitoring and policy-oriented risk assessment to safeguard public health, promote sustainable fishery management, and support the objectives of global frameworks such as the SDGs. The findings contribute valuable baseline data for ecological risk mitigation and informed policymaking in freshwater ecosystems.