Microplastics Footprints in a High-Altitude Basin of the Tibetan Plateau, China

Abstract

Microplastics (MPs) are ubiquitous in the environment and have been drawing increasing attention; however, MPs’ occurrence and behavior in remote areas are not well understood. In this study, we quantified and characterized MPs from surface waters and sediments in a remote area, namely the Tibetan Plateau, China. The samples were collected from the Lhasa River and the lower reaches of the Brahmaputra River to better understand MPs’ sources to rivers of the Tibetan Plateau. MPs’ concentrations in water and sediment were 735 items/m3 and 51 items/kg, respectively, and the dominating MPs observed were fibers with size ranging from 100 to 500 µm. MP abundance increased nearly two-fold from upstream to downstream in the Brahmaputra River, associated with the inputs from downstream human activities and the inflows of tributaries (especially the Lhasa River). This study provides important bases for analyzing MPs migration processes in the plateau region.

Keywords

• microplastic
• water
• sediment
• Brahmaputra River
• Tibetan Plateau