Characterization of suspended microplastics in surface waters of Chalakudy River, Kerala, India

The investigation focused on identification and quantification of microplastics in surface waters of Chalakudy River, Kerala. Microplastics were detected in the surface waters of the study area with a recovery rate of 108.33 mg particles L−1. The abundance of microplastics ranged from 15.13 ± 4.13 – 170 ± 17.75 particles L−1 (mean: 55.81 ± 34 particles L−1). A maximum number of microplastics were obtained from site C3 and the least from site C8. The weight distribution of microplastic on sites exhibited strong positive correlation with the abundance (r = 0.83). Microplastics of size <20 µm were in higher abundance in the study area. Microscopic examination revealed fragments (47.06%) as predominant plastics and the dominant colour was brown/mud (26.99%). Abundance of coloured plastics indicated the probability of damage to aquatic life. Raman spectrum analysis revealed that Low-Density Poly Ethylene (40%) as the predominant polymer that could be observed at all the sampling sites. Lower-sized microplastics would cause accidental ingestion by organisms. The estimated release of a higher average number of microplastic particles (55.81 ± 4.25) into the marine environment is of serious concern. The observed overall abundance and recovery rate of microplastics in the study area indicated the status of contamination due to a multitude of sources.