Elemental Composition of Aerosols in the Near-Surface Air of Moscow: Seasonal Changes in 2019 and 2020

The seasonal changes in the elemental composition of surface aerosol in Moscow are considered in four data series: for summer and autumn 2019 and winter and spring 2020. The surface aerosol is significantly enriched with sulfur, heavy metals, and metalloids (Cu, Zn, Cd, Sb, Pb, Bi, etc.). The mass concentrations, mass percentages, and enrichment factors for different elements in aerosol particles are determined and compared for different seasons. The spatial distribution of elements in surface aerosol is not uniform through the city, which may be associated with the specificity of local sources, underlying surface, and wind regime in different regions of Moscow. The highest concentrations of a number of terrigenous and anthropogenic elements are revealed in the Central Administrative District of Moscow. The causes for seasonal variability in the elemental composition of surface aerosol in the Moscow megalopolis and possible sources of elements are discussed.