Potentially toxic elements distribution in urban, agricultural and pinewood soils

Potentially toxic elements (PTEs) abundances in top soil and along the soil profiles from areas affected by different anthropogenic inputs were investigated. The study area is located within the Ravenna Municipality, a complex territorial system highly affected by industrial (a large petrolchemical complex) and agricultural activities. Three zones with distinct environmental features were identified: the San Vitale Pinewood affected by atmospheric deposition pollutants from the industrial complex (PIN 1, PIN 4, PIN 6 and PIN 8 soil profiles); a public garden within the Ravenna city centre, mainly affected by traffic pollution (GP 1 soil profile); the "Luigi Perdisa" farm located immediately northwards Ravenna was selected due to the use of fertilizers as well as atmospheric deposition (PER 2 soil profile). The total concentration of PTEs (Ba, Cr, Cu, Ni, Pb, and Zn) was determined by X ray fluorescence spectrometry (XRF), and the pseudo-total concentration with Aqua regia digestion (AR) and ICP-OES quantification in order to evaluate the extractability of the elements. Results showed a significant increase of some PTEs (Cu, Pb, and Zn) in the topsoil compared to the pedological substrate. In the Ravenna urban park (GP1 station), Pb and Zn concentrations exceeded the threshold values established by current Italian laws for soils from "public, residential and private areas" (D. Lgs 152/2006). The correlation between topsoil and the subsoil highlighted that some PTEs, such as Cu, Pb and Zn, are anthropogenic and they are mainly associated to the deposition of airborne pollutants, whereas other elements (Cr and Ni) are lithogenic