Microplastic contamination in the pristine waters of Tilicho Lake, Nepal: A groundbreaking study in the high-altitude himalayas

Microplastics (MPs) are studied extensively in various environments worldwide; however, their presence in remote, high-altitude freshwater lakes remains underreported. These alpine lakes serve as both upstream water sources and sinks for MPs, highlighting the urgent need for scientific investigation. In this study, we present the first assessment of MP contamination in Tilicho Lake-located at an elevation of 4,917 m.a.s.l., among the world's highest lakes and a popular destination for Himalayan trekkers. Surface water samples from six different nearshore locations revealed an average MP concentration of 42 ± 18 particles per liter. Spatial variability in MP levels showed a strong correlation with the level of tourist accessibility, indicating that tourism and associated plastic waste are significant sources of MP contamination. This growing MP pollution, intensified by increasing tourism and climate change, highlights the pressing need for strengthened policies and environmentally sustainable practices to protect these ecologically sensitive alpine environments.