Distribution and characteristics of microplastics in fluvial sediments from the Koshi River Basin, Nepal - Alisha Dahal; Bishal Dahal; Sagar Sitaula; Rupesh Bohara; Ramesh Raj Pant; Yukti Acharya; Khaga Raj Sharma; Basant Giri; Bhanu Bhakta Neupane (Environmental Pollution, 2025)