Heavy Metal Migration in Soil-Plant System in Conditions of Urban Environmental Pollution

Abstract

This study is devoted to heavy metal soil migration to coltsfoot in urban pollution of Tyumen city. Soil and plant samples were collected in the summer of 2017 to 2020 at the control site, highway, engine-building, oil refinery, battery manufacturing, and metallurgical plants. Heavy metals (Cu, Zn, Fe, Mn, Pb, Cd, Ni, Co, and Cr) mobile and acid-soluble forms in soils, and metals concentration in plants were analyzed by atomic absorption and atomic emission spectroscopy. Metals concentration in soils of urban area exceeded the control by 1.1 to 20 times. Relative accumulation of metals decreased in the order: Pb > Cu > Zn > Ni > Cr > Fe > Co > Mn > Cd. Heavy metals mobility in soils decreased in the order: Cd > Mn > Pb > Zn > Ni = Cu > Co > Cr > Fe. Coltsfoot metal accumulation changed in the order: Fe > Zn = Mn > Pb > Cu > Cr > Co > Ni > Cd. The highest contamination for most of the metals was at the metallurgical plant, while Ni and Co concentrations were maximum at the oil refinery. Content of Cu, Zn, Fe, Cd, Ni, and Co in coltsfoot correlated with a concentration in soils. Bioconcentration factor showed the following metal bioavailability: Cu > Zn > Cd > Pb > Ni > Mn > Cr > Co > Fe. Heavy metal accumulation in coltsfoot should be taken into account during sanitary control of herb drugs based on this plant.