Heavy metals in coastal soils and sediments of the ponds in Samara

Abstract

The total contents of Mn, Cr, Ni, Cu, Zn, Pb and Cd in foreshore soils and bottom sediments of 20 ponds have been investigated for the first time in Samara by the method of spectrometry with inductively coupled plasma. It is shown that polymetallic pollution of coastal soils and bottom sediments of 16 ponds out of 20 considered is acceptable; 3 ponds, located in the 13th microdistrict (small pond) and on the Solnechnaya street (large and small ponds), are characterized by moderately hazardous pollution with heavy metals; 1 pond, located in the area of the former Hippodrome, has a high level of pollution of coastal soils. Cu, Zn and Pb should be considered to be the main elements that significantly affected the ecological state of coastal soils and bottom sediments of the studied ponds. Their content in selected samples ranged: from 0,3 to 20,3 for Cu, from 0,2 to 14,9 units for Zn, from 0,2 to 25,2 units of background concentrations to Pb. The analysis of heavy metals average levels in coastal soils and bottom sediments of Samara ponds showed, that bottom sediments were enriched with all analyzed metals except Mn in comparison with coastal soils, whereas Mn was accumulated to upper levels in coastal soils. The location of water bodies in various parts of the urban area relief caused differences between the levels of heavy metals accumulation. For instance, the coastal soils of the ponds located on the watershed between the Saratov reservoir and the Samara River accumulated heavy metals more actively than the coastal soils of the ponds on the Volga slope. The accumulation of heavy metals in bottom sediments on the watershed was more active for Mn, Cr, Zn and Cd whereas in the ponds on the Volga slope it was shown for Ni, Cu and Pb.