Hydrogenic heavy metal pollution of alluvial soils in the city of Perm

The differences in the sources and compositions of the pollutants among the alluvial soils within the city of Perm were revealed. Heavy metal pollution of hydrogenic origin is caused by unpurified sewage water. The main source of pollution of the urbanozems and replantozems of the city is the aerial input of heavy metals. The lead content in the alluvial soils of the city was twice lower and the mean Zn and Ni contents were 1.5 and 4.0 times higher than in the urbanozems and replantozems, respectively. The concentrations of Sr, Zn, Ni, Cu, and Cr did not correlate positively with the content of clay particles in the fine earth of the alluvial soils. The higher pollution of the light-textured soils showed that, nowadays, its main source was sewage water but not sludge. In the alluvial soils, small Fe-rohrensteins are formed. They serve as microgeochemical barriers for some part of the microelements. The Pb and Zn contents in the rohrensteins of the soils of the Las’va river basin reached 440 and 890 mg/kg, respectively. In the upper horizon of this soil, the contents of Pb and Zn in the rohrensteins were 42 and 17% of their concentration in the fine earth, respectively.