Microplastic pollution in Himalayan lakes: assessment, risks, and sustainable remediation strategies

Microplastic contamination is a newly emerging environmental problem in the ecologically sensitive Himalayan lakes, posing a threat to biodiversity, water quality, and human habitation. These high-altitude freshwater ecosystems are being increasingly polluted through human use, tourism, glacier melt, and atmospheric deposition. Microplastic quantification in such isolated locations is, however, limited by factors such as harsh climatic conditions, logistical challenges, and the need for expert analytical techniques like microscopy and spectroscopy. The present review considers sources, pathways, and ecological impacts of microplastics in Himalayan lakes compared to other sensitive aquatic ecosystems. The review describes existing remediation technologies, categorizing these into physical, chemical, and biological interventions, and takes into account emerging sustainable approaches, including biofilm-mediated degradation and nanotechnology-based solutions. The application of nanomaterials for microplastic removal is elaborated in detail, and case studies validated their effectiveness, especially in cold environments with strong UV irradiation. In the face of increasing worldwide research into microplastic contamination, there remains a huge knowledge gap concerning its behavior in distant, elevated lake systems such as the Himalayas. The most important areas to focus with regard to the ecotoxicological impact of microplastics are the bioaccumulation of microplastics in the Himalayan food web, plasticizer toxicity, and long-term potential health and ecological threats. This review addresses the imperatives of enhanced governance, monitoring, legislation, and community-based mitigation measures. This research makes a contribution by integrating region-specific data, defining priority research needs, and provoking sustainable, multidisciplinary solutions specific to freshwater cold-climate ecosystems. This contribution serves to address the imperative of adopting multidisciplinary research, region-specific remedial measures, and judicious estimation of microplastic contamination of high-altitude lakes through by describing research gaps. It distills the present scenario and promotes novel, environmentally friendly remedial measures, regulatory policies, cooperative initiatives to combat microplastic pollution, and vulnerabilities in the fragile Himalayan freshwater aquatic ecosystems.