Characteristics of microplastic pollution in the rivers of the Fergana Valley, Central Asia.

Microplastic pollution is becoming one of the most pressing environmental issues of our time, especially in aquatic ecosystems, where it negatively impacts aquatic organisms and water quality. In different countries of the world, water pollution by microplastics has its own characteristics associated with the predominant sources and economic structure. Although numerous studies have been conducted worldwide, data on microplastic pollution of surface waters in Central Asia remain limited. Rivers in the Fergana Valley have not been previously studied. This creates the need for detailed studies to assess the scale and sources of microplastic pollution in this region. The aim of this study is to investigate the content, morphology and polymer composition of microplastics in surface waters of rivers in the Fergana Valley flowing through the territory of Uzbekistan. To achieve this goal, the following objectives were set: collecting water samples in the Sokh, Chodaksay, Govasay, Kasansay, Chartaksay and Andizhansay rivers; determining the concentration of microplastics in the collected samples; conducting a morphological analysis of the particles; determining the polymer composition of microplastics using microscopy combined with Raman spectroscopy (micro-Raman). The results of the study showed that the average concentration of microplastics in the surface waters of the studied rivers varied from 2.89 to 7.00 pcs./m³. Morphological analysis revealed the prevalence of fibers (83.7% of the total number of particles recorded), microplastics were mainly polyethylene terephthalate (PET), which accounted for 47.3% of all particles. The morphology and polymer composition of the particles indicate textile materials as the main potential source of river pollution. The results obtained demonstrate for the first time the level and nature of microplastics pollution of surface waters of rivers in the Fergana Valley. They highlight the need to develop effective strategies to reduce pollution by PET textile fibres and other microplastics in the region and conduct further research to assess their impact on ecosystems and human health.