Potentially Toxic Elements in Urban Soils in the Oil and Gas Region of Northern Western Siberia (Novy Urengoy, Nadym, and Noyabrsk)

The chemical composition and properties of surface soil horizons (0–10 cm) and PM10 fractions were studied in three cities of northern Western Siberia (Novy Urengoy, Nadym, and Noyabrsk). The content of Al, Fe, Sc, V, Cr, Co, Ni, Cu, Zn, As, Sr, Mo, Sn, Sb, Cs, Ba, W, Pb, Bi, and U are determined by atomic emission spectrometry and inductively coupled plasma mass spectrometry. The average content of potentially toxic elements in urban soils is shown to be lower as compared with the element abundances in the Earth’s upper crust. The concentrations of Pb, Zn, Sb, and Sn in PM10 particles are 4–16-fold higher than the total content in soils. In Novy Urengoy, PM10 particles are enriched with Sb and Zn; in Nadym, with Sb, Zn, Pb, Ni, Cu, and V; and in Noyabrsk, with Sb, Zn, Ni, Pb, and Cu. Wider associations of pollutants are identified based on the EF (enrichment factor) values of the elements in PM10 particles. W, As, Sn, Bi, Mo, and Cu appear in the pollution profile. In all cities, Sb and Zn display the highest EF values. The most contrasting Sb anomalies are characteristic of road intersections and transport infrastructure facilities. According to the total EF, urban soils have an intermediate level of pollution versus the PM10 particles, polluted at a high level with Ni, Zn, W, and Cu as the key contributors. The main sources of elements are identified by the principal component analysis. The formation of the Ni–Co–Cr–W association is associated with lithogenic component and the Ba–Pb–Cs association, with organic matter. Characteristic of all cities is the accumulation of Zn, Sb, Cu, Pb, and Mo, the association that indicates a key role of motor vehicles in the contamination of urban soils.