Assesment of heavy metals concentration in initial soils of post-mining landscapes in Kryvyi Rih District (Ukraine)

Assessment of heavy metals content in the initial soils of the post-mining landscapes plays an important role in pollution control, ecological protection, and safe-guarding human health. In this study, the site-specific pedogeochemical background contents of several metals in soils in Kryvyi Rih Iron Ore Mining & Metallurgical District (central part of Ukraine) were determined. The metal concentrations in the soils of Petrovsky waste rock dump were also quantified and were also assessed using indices of pollution. The field sampling was carried out at a depth of 0-10 cm in five plots in dump area and in one plot in control site. The 43 soil samples were collected. The results showed that local background concentrations of heavy metals in soils of studied area decreased in the following order (mg×kg-1): Fe (42 510) > Mn (761.7) > Cr (94.48) > Zn (90.51) > > As (31.85) > Cu (28.10) > Pb (18.73) > Co (16.21) > Sn (4.64) > Mo (0.28) > Cd (0.16). In the initial soils of devastated lands at Petrovsky waste rock dumps the predominance of increased Cd, Co, Fe, Mm, Mo and Sn content and the predominance of decreased As, Cr and Pb content were observed. Based on the mean values of the individual indices of pollution (Pollution index, Geoaccumulation index, Enrichment factor, Contamination factor) can be assumed that in these soils As, Cd, Fe, Mo, Pb and Sn are mostly coming from industrial activities. Co, Cr, Cu, Mn and Zn are mostly related to their natural occurrence in devastated lands. The values of integrated indices of pollution (Nemerow pollution index, Pollution load index, Degree of contaminated, Modified degree of contamination) indicated that the initial soils of post-mining landscapes can be evaluated as no polluted – and extremely heavy polluted.