Microplastics in the Snow Cover of Urban Landscapes: A Case Study of Barnaul

This article presents the results of a study of the spatial distribution of microplastic (MP) pollution of urban snow cover conducted on the territory of the Barnaul urban agglomeration. The algorithm of the study involves the following sequential steps: snow sampling, the identification of MP particles, a calculation of the total particle abundance in the sample, and a concentration assessment. In total, 49 snow samples from various parts of the city were taken for the study in the first decade of March 2021. They were stored in 3-L glass containers. MP particles were detected using a scanning electron microscope. MPs are found in all snow samples in concentrations from 27 to 595 items/L, with an average concentration of 125 items/L. The city of Barnaul is located on three natural landscapes: uvals of the Ob Plateau, a dell formed by an ancient river runoff with a ribbon forest, and the Ob Valley. The maximum amount of MP particles is found in the snow cover of the Ob Plateau and the minimum is in the Ob Valley. The next stage involved assessing the level of MP pollution of the city across six functional zones. Assessment results show that the maximum average concentration of MP particles in Barnaul during the winter period is typical for urban green spaces (parks and squares) in all districts of the city. The possible reasons for that are the continuous accumulation of snow in such areas throughout the entire cold weather period and the so-called "comb-out" effect associated with the ability of plants to filter particles of dry atmospheric deposition. The snow cover of Barnaul is found to contain MP particles of all five main shapes: granule, foam, fragment, film, and fiber.