Chemical Characterization and Spatial Distribution of Microplastics in the Surface Water of the Arun River Basin, Central Himalaya, Nepal - Sagar Sitaula; Niru Basnet; Somy Bhattarai; Rupesh Bohara; Ramesh Raj Pant; Bishal Dahal; Alisha Dahal; Basant Giri; Bhanu Bhakta Neupane (Water, Air, & Soil Pollution, 2026)