ИСТИНА

Since inhalation is dependent on particle size, atmospheric particulate matter (PM) fractions as well as detailed size-fractionated characterization of inorganic particles in PM is of great interest (Eleftheriadis et al., 2014). In this respect, megacities such as Moscow with over ten million inhabitants require a special focus. We present the results of the ongoing investigations aiming at an in-depth characterization of Moscow PM, based on the determination of trace elements (TE) and ionic fraction profiles both in PM10 and in size-segregated aerosol samples. As a northern latitude megacity, this type of investigation is expected to fill fundamental gaps in the understanding of atmospheric dynamics in such a peculiar urban landscape, wherein systematic and up-to-date studies, started to be implemented. Two sampling campaigns have been performed at the Aerosol Complex of Moscow State University at southwest of Moscow, classified as urban background site, the first one from April 2018 to December 2019, and the second one from September 2021 to August 2022. PM filters have been collected with a MOUDI impactor, then analyzed by ion chromatography (IC), proton-induced X-ray emission (PIXE), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). All these methods are well-suited to size-resolved elemental and ionic speciation of atmospheric aerosols. Correlations between TE and ions were evaluated, in conjunction with meteorological data, and chemometric analyses were carried out to shed light at a higher degree of detail on aerosol sources, environmental fate and health hazards in Moscow megacity airshed.