Lead (Pb) and Zinc (Zn) Levels as Pollution Indicators

The aim of this study was to determine and evaluate the concentrations of the heavy metals Lead (Pb) and Zinc (Zn) in soil and plants and the potential contamination of soil by these metals, resulting from the deposition of vehicle emissions, in areas on the fringes of the Presidente Dutra motorway, in the Paraíba do Sul river valley in the south-eastern region of Brazil. The results found for the soil samples were evaluated according to the methodologies that suggest the guideline values for soils in the state of São Paulo and the reference values and tolerance limits for Brazilian soils. The results showed that in the areas under study there was a decrease in the concentration of Lead and Zinc with distance and depth and a greater enrichment of these metals, especially at a distance of 0 to 10 m from the edge of the motorway, presumably due to the deposition of emissions from motor vehicles. Considering the reference values and tolerance limits for Brazilian soils, the soil on the banks of this motorway is contaminated with the metal Zn.