Sources of anthropogenic contamination of soil in the Upper Silesian Agglomeration (southern Poland)

This assessment of the environmental degradation by toxic chemical elements within the Upper Silesian Industrial Agglomeration of Poland encompasses the impact of mining for base metals and coal and non-ferrous metalurgy, as well as the discharge of industrial and municipal sewage causing strong degradation of the natural environment in the area over the years. The content of the following elements: Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, P, Pb, S, Sn, Sr, Ti, V and Zn has been assessed both in the topsoil (0.0-0.3 m) and the subsoil (0.8-1.0 m) of the study area. Concentrations of the elements in the <2 mm soil fraction were analysed using the ICP-OES method after Aqua regia extraction. The soil contamination was assessed based on the enrichment factor (EF) and geo-accumulation index (Igeo). The tests revealed elevated contents of several metals, arsenic and sulphur, exceeding the regional geochemical background levels. Unusually high concentrations of the following elements: As (up to 5,300 mg/kg), Cd (up to 388.8 mg/kg), Cr (up to 1,638 mg/kg), Cu (up to 13,230 mg/kg), Hg (up to 23.44 mg/kg), Mo (up to 93.7 mg/kg), Pb (up to 54,940 mg/kg), Sn (up to 701 mg/kg) and Zn (up to 88,120 mg/kg) were recorded. The highest concentrations of these elements were found in the proximity of smelters and residential areas. The spatial distribution of metals is shown as interpolated data on maps and compared with the locations of mining and industrial sites.