Metals, Metalloids, and Benzo[a]pyrene in PM10 Particles of Soils and Road Dust of Alushta City

Abstract

The chemical composition of PM₁₀ particles (<10 μm or 0.01 mm in diameter) of urban soils in different functional zones and in road dust on different types of roads in the city of Alushta was determined for the first time. The studied urban soils and road dust accumulate Zn, Sb, Pb, Cu, Cd, and benzo[a]pyrene (BaP) mainly supplied by motor vehicles. The rate of ecological hazard of contamination of PM₁₀ particles by heavy metals (HMs) and BaP in soils and dust was assessed, and the spatial distribution of the pollutants was studied. The total contamination of soils and road dust by HMs is low, whereas their pollution by BaP is extremely high within about 50% of the city area. The concentrations of BaP and many HMs in PM₁₀ particles is 1.5–4 times higher than their content in the bulk soil mass, which determines the hazardous contamination level of PM₁₀ particles in the soil over about 25% of the city area and in road dust particles over about 70% of the area. The most contaminated PM₁₀ particles were revealed in soils of the transport and residential–recreational zones and in road dust along large roads. The seasonal variability of contamination of PM₁₀ road dust particles by HMs was studied. In winter, the contents of HMs related to vehicle emissions (Zn, Cd, Sn, Sb, and Pb) decreases, whereas the concentrations of HMs released from heating systems (Mo and Bi) rises. The behavior of other HMs is virtually independent on the season.