A Comprehensive Assessment of Microplastic Contamination in the Kodayar – Kuzhithurai River System of Kanyakumari District, Tamil Nadu, India and Its Potential Human Health Impacts Through Drinking Water Exposure

Abstract

Microplastics (MPs), generally defined as plastic particles smaller than 5 mm, have emerged as contaminants of global concern due to their persistence, widespread distribution, and potential adverse effects on ecosystems and human health. Freshwater rivers are recognized as critical pathways for transporting microplastics from terrestrial sources to estuarine and marine environments while simultaneously serving as major sources of drinking water for millions of people. Despite increasing global concern, limited scientific information exists regarding microplastic contamination in river systems of southern India, particularly within the Kodayar–Kuzhithurai river basin of Kanyakumari District, Tamil Nadu.

This study proposes a comprehensive investigation of microplastic occurrence in river water collected from ten strategically selected locations, namely Netta, Kazhiyal, Thirparappu, Vazhaithottam (Arumanai), Thikkurichi, Mathoor, Kuzhithurai, St. Mangad, Parakkani, and Thengapattanam. The research aims to evaluate spatial variation, identify dominant polymer types, classify particle morphology, investigate potential contamination sources, and assess possible human exposure through river water consumption. Standardized laboratory techniques, including density separation, wet peroxide oxidation, vacuum filtration, stereomicroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and Scanning Electron Microscopy (SEM), are recommended for characterization. [1-17]

The study also proposes a human health risk assessment framework by estimating potential annual ingestion of microplastics through drinking water and discussing possible toxicological implications of associated plastic additives such as bisphenol A (BPA), phthalates, and heavy metals. The outcomes are expected to provide baseline scientific evidence supporting water quality management, environmental monitoring, public health policy, and plastic waste reduction strategies within the river basin. This work will contribute to the growing understanding of freshwater microplastic pollution in tropical river systems and establish a reference dataset for future environmental and epidemiological studies.