Spatiotemporal distribution of microplastics and associations with river water physicochemical and hydrological parameters, including risk assessments in four tropical rivers in Sarawak, Malaysia

Abstract The microplastic pollution of freshwater systems has been a global environmental concern, yet there is a lack of knowledge on tropical rivers. This paper examined the relationships between spatiotemporal microplastic abundance and river water physicochemical and hydrological parameters in the surface water of four rivers of Sarawak in Malaysia (Baram, Miri, Sibuti, and Niah), followed by ecological risk assessment using PLI, PHI, and PERI indices. Surface waters were collected during dr