# Pilot Study of Microplastics in Snow from the Zhetysu Region (Kazakhstan)
## 3 Results and Discussion
When the snow cover melts, the particles either can infiltrate into the upper soil layers or can concentrate on the surface. They can also be re-transported by erosion and surface flows, as well as by the wind, after the surface becomes dry. Thus, microplastic, first found in snow, can further move to other ecosystem compartments--soil, surface water--demonstrating the cyclicity and wide migration ability of this pollutant, which in turn poses a potential threat, not only to soil and aquatic organisms [61,62], but also to human health. Microplastics are carriers and adsorbents of toxic pollutants such as heavy metals, polychlorinated biphenyls, polyaromatic hydrocarbons, and pesticide residues [63]. Once entrained in snow, such \"loaded\" microplastic particles can, upon melting, transfer the sorbed toxins into soil and water, thereby raising their local concentrations. In addition, the presence of microplastics together with other contaminants can produce a combined negative effect on living organisms; for example, an organism that ingests plastic particles simultaneously receives a dose of the chemicals adsorbed on their surfaces. The analysis of the presented images of wind directions over the Zhetysu region of Kazakhstan presented from [[https://earth.nullschool.net/](https://earth.nullschool.net/)]([https://earth.nullschool.net/](https://earth.nullschool.net/)) (accessed on 30 April 2025) for the period from November 2024 to February 2025 shows that in November and December, westerly and north-westerly winds prevailed, contributing to the transfer of microplastic pollution from western and north-western territories of Kazakhstan (Figure 5). Figure 5: Wind directions over the territory of the Zhetysu region. (Presented from [[https://earth.nullschool.net/](https://earth.nullschool.net/)]([https://earth.nullschool.net/](https://earth.nullschool.net/)) access site, accessed on 30 April 2025). In December, there are also air flows from south-west direction (Figure 5), which increases the probability of pollution transfer from southern areas and neighboring countries such as Uzbekistan and Kyrgyzstan. In January, the wind direction becomes predominantly northerly and north-westerly, which increases the possibility of pollution transport from northern regions of Kazakhstan as well as north-western areas of China. February is characterized by a more complex wind pattern: wind flows from west, north, and south-east, which significantly expands the potential pollution sources and increases the probability of microplastic input from various, including distant, territories of China and Central Asia. In winter, snow plays an important role, which effectively captures and precipitates atmospheric pollutants, including microplastics, significantly increasing the range of their transfer and causing pollution of the Zhetysu region to be highly probable, not only from domestic sources but also from abroad, primarily from China, Uzbekistan, and Kyrgyzstan. Thus, contamination of the snow cover of the Zhetysu region with microplastics is caused by a complex combination of factors, among which the leading role is played by the long-range atmospheric transport and migration ability of particles, mediated by the altitude of the terrain, local climatic and meteorological conditions, and proximity of cities and agricultural areas.