Microplastics in water from the Cooum River, Chennai, India: An assessment of their distribution, composition, and environmental impact

Widespread nature of microplastics in rivers and their tributaries causes enormous harm to the aquatic environment. The present study investigates quantity, color, size, form, and composition of microplastics present in water from the Cooum River of Chennai in India. A total of 341 microplastics observed in water samples (n = 10) were characterized by transparent particles (42%) of mainly polyethylene terephthalate (PET) and polypropylene (PP). About 69% of the particles with size <1000 μm raise the possibility of being ingested by aquatic species. Fiber was the most common shape (48%), followed by film (20%), pellets (12%), fragments (12%), beads (5%), and foam (4%). Variable abundances of different shapes demonstrate a variety of sources, including the textile fibers and plastic breakdown. Polymers with high-risk ratings such as nylon and polypropylene are reflected with an estimated high Polymer Hazard Index (PHI >1000) in some samples. Pollution Load Index suggested that samples along the river are moderately contaminated with microplastics. However, the Polymer Hazard Index (PERI) showed low ecological risk in the metropolitan area, river mouth, and potential fishing zones. These findings highlight ecological impact from the ubiquity of microplastics in waters from the Cooum River. Thus, the minimizing of microplastic pollution would require immediate action, including the implementation of stringent waste management and pollution reduction techniques.