Influence of a Municipal Solid Waste Landfill on the Soil Levels of Heavy Metals at Adjacent Territories

The levels of heavy metals (Cr, Cu, Zn, Ni, Pb) in the soils of the areas adjacent to the Sharra municipal solid waste landfill located about 7 km south-west of the center of Tirana (Republic of Albania), were determined. The studied soils are classed with subtropical brown. Fourteen sections of land were selected for sampling, each having three spots 100x100 m in size: 12 section in the area of the landfill, as well as 1 section, "conditionally background," at a distance of 0.8 km and 1 section, background, at a distance of 1.5 km from the landfill. The conditionally background section is located at a territory with similar terrain, geological structure, and soil cover. The background section is characterized by soil and geological conditions maximally close to the landfill territory. It was found that the levels of Ni and Cr in all samples were 2.2-4 and 2-4.3 times higher than the maximum allowable concentrations (MACs), while the levels of Cu, Zn, and Pb not. At a distance of 800 m from the landfill, the Ni and Cr levels almost halved, but at the same time remained above the MAC values. The Cu and Zn concentrations in all samples were higher than those in the samples from the background" and conditionally background spots; the Pb concentrations in this case fluctuated around the background level. In addition, The levels of all the metals in the upper soil horizon demonstrated high variability, which is not typical for natural brown soils and points to pollution of the soil cover. Thus, convincing evidence was obtained to show that the Sharra landfill of solid municipal waste is a source of soil pollution, largely with Ni and Cr and to a lesser extent with Cu and Zn.