Spatial distribution and compartmental storage of microplastic particles in a tropical lowland river system (Perak river, Malaysia) - Sarva Mangala Praveena; Muhammad Nifail Sharif; Alif Ilhami Mohd Zamri; Mohd Amir Md Khalid; Mohd Firdaus Mohd Anuar; Vita Pramaningsih; Samuel Abiodun Kehinde (Physics and Chemistry of the Earth, Parts A/B/C, 2026)