Journal article Open Access
The city of Torino (45°N, 7°E NW Italy) has a long history of heavy industry. Additional sources of potential pollutants originate from transport such as car emissions. We selected an area potentially at high risk of contamination: it is sandwiched between roads, the circular Turin highway and the motorway which connects to France, and a landfill where special and hazardous solid wastes from industry are disposed of. Our main aim was i) to discriminate between these sources of heavy metals (HM) and ii) to assess a simplified HM transfer scenario. We started with air diffusion models (inputs were meteo and chemistry of the particulate), then we described topsoils (12 samples km-2) and we sampled, reallocated undisturbed, and cultivated an Ap soil horizon, being the soil ceteris paribus. The topsoils description discriminated Factor I, related to the vehicular load and soil parent material (mainly Cd, Co, Cr, Ni, V, and Zn), and Factor II, HM univocally dispersible from the landfill (Sb and As). The ecosystem response is resilience: soil tends to buffer loadings of most HM. In the case of mercury, lead, and arsenic our findings indicate that their transfer to the food chain may be massive.