An extensive individual particle analysis of solid airborne particles collected in a moderately urbanized area

Detailed individual particle characterization of PM₁₀, in terms of particle size, morphology, and elemental composition, was done using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. The samples were collected in four localities in the Czech Republic (Central Europe), three of which are medium-sized cities, and one is a natural locality in the mountains. More than 1600 particles obtained from each locality were evaluated. During the sampling period (1.9.-8.9.2019), the atmospheric conditions were similar in the localities, which enabled the identification of PM₁₀ characteristics common to all the sampling sites. Some differences in the particles' morphology and composition, arising from site-specific conditions, were observed too. The most abundant elements in the PM₁₀ were C, O, Si, Fe, Al, Ca, Na, K, Mg, and S, but some toxic elements (Cr, Cu, and Ni) were also detected. The main component of the PM₁₀ is carbon, whose multimodal distribution indicates that the particles contain different carbonaceous chemical compounds. The distribution of carbon in the natural locality was different compared to the other sites, suggesting a specific character of the sources of carbonaceous compounds in this region. Last but not least, a relationship between Al, Si, and O concentrations was found, which implies the presence of aluminosilicates and silicon dioxide (possibly sand) of crustal origin in the particles.