Assessment of Peat Pollution by Heavy Metals Depending on the Depth of Occurrence

Peat was studied in order to assess the concentrations of heavy metals in it depending on the depth of occurrence. Genetically homogeneous peat layers with occurrence depths of 0-5, 5-35, 35-85, 85-140, 140-220, and 220-375 cm were analyzed for the concentrations of Ag, Hg, Pb, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Tl, and As. The metal concentrations were determined on an ICP-MS Aurora Elite inductively coupled plasma mass spectrometer (Bruker, Germany) using an internal standard containing the elements Bi, In, Li, Sc, Tb, and Y. The determination conditions were selected using a certified soil standard. The highest concentrations of the test metals were observed in the upper layer of peat, and the concentration of metals decreased with depth of peat occurrence. A regularity was observed only for the elements Mn, Tl, Co, Ni, and Pb, and the other metals were uniformly distributed in peat layers and exhibited no regularity.