Magnetite contamination of urban soils in European Russia

Urban soils are enriched in magnetite (Fe3O4), thanks to aerial emissions of industry, energy and cars emission. Magnetite contamination of urban soils in Russia has both common features of the world and its specificity. The magnetite content through the magnetic susceptibility is used as an indirect indicator of the contamination degree of urban soils with some heavy metals. In the cities of Russia: Moscow, Cherepovets, Perm and Chusovoy, magnetite soil pollution is in agreement with some of the heavy metals pollution. The correlation coefficients between magnetic susceptibility and mobile forms contents are higher than coefficients with a total contents of heavy metals. The volume magnetic susceptibility, measured in the field conditions, is less correlated with the pollution of urban soils with heavy metals than an express specific magnetic susceptibility, which is determined in the laboratory. In Moscow and Chusovoy, magnetic susceptibility of soils is high in the territory of the old town and it is the lowest in the field of new buildings. Soil magnetic susceptibility is indicator of Cu, Zn and Pb in Moscow. Soil magnetic susceptibility is indicator of Pb, Zn and Cr in Cherepovets. In Chusovoy, the oxidation degree of the magnetite is low, and a stoichiometric index of magnetite is high; soil magnetic susceptibility is indicator of Mn, Zn and Cr. In Perm, the magnetic susceptibility of magnetite in the soils is low, but it is highly variable; soil magnetic susceptibility is indicator of Ni, Zn and Cr.