Soil control of trace metals concentrations in landfills: A case study of the largest landfill in Europe, Malagrotta, Rome

• We analysed trace metals in soils sampled in landfill.
• We used the metal EF, Igeo and the statistical analysis to characterised the soil.
• The Malagrotta area is moderately polluted for some of the studied metals.
• The results show that soil controls the elements enrichment.

Thirteen soil samples were collected in April 2009 in Malagrotta's landfill, near Rome, to evaluate the geochemical factors that control the distribution pattern of trace elements and to define their natural and/or anthropogenic sources. Although the As and Pb mean values are lower than the natural background values for the sampled soil and the mean values of the other trace metal contents were lower than the natural abundance in the lithosphere and in the soil values, the geoaccumulation index (Igeo) suggests that the Malagrotta area is polluted by some of the studied metals. Moreover, a statistical analysis suggests that Cu, Zn, Cd, Sb, Pb, Cr, Ni and As constitute anthropogenic components, whereas the remaining elements (Tl, Rb and V) appear to be associated with parent rocks. It is demonstrated that the background may change from an area within a region and between regions. It's important that regulators recognise that the background depends on location and scale.