Abstract
Microplastics have emerged as another dimension of hazardous and persistent pollutants afflicting every corner of the globe, even permeating critical biodiversity hotspots. This study aims to serve as a preliminary report on the occurrence and assessment of MP pollution in shore sediments of four selected rivers in the state of Mizoram, which lies in one of the sensitive biodiversity hotspots in India, and is also a part of the eastern Himalayan range. There have been minimal studies on microplastic pollution in this region despite its critical ecological location. Four freshwater rivers, namely Chite, Tlawng, Serlui-A, and Tuirial, were selected for the study due to their proximity to urban settlements and have been subjected to rampant plastic pollution. The study revealed that MPs were detected from all sampling sites, and abundance was highest in Chite, which runs through parts of Aizawl city. Particles within the size range of 0.15-0.25 mm were found to be the highest in numbers in all sampling locations, while MPs between 3-5 mm were the least in number. The shapes of MPs were varied, constituting fragments, fibers, pellets, and spheres, with fibers (40%) being the dominant shape overall. Polyethylene was found to be the dominant polymer type among particles analyzed using FTIR spectroscopy. This study contributes to the imperative assessment of MP pollution in river sediments of the eastern Himalayan region of India, as comprehensive research in this regard is still lacking.