In southern European cities, accumulation and resuspension of road dust are favored by the scarce rainfall as compared to central and northern countries. Indeed, a comparison of several European studies shows that PM in Mediterranean countries is considerably enriched in mineral dust: soil fraction accounts for 22% in Amsterdam whilst 65% in Athens (Sillanpa¨a¨ et al., 2006), mineral dust achieves 10 mg m3 in Spain while 2–5 in central Europe and 7–9 in Sweden (Querol et al., 2004). Viana et al. (2007) registered 23–33% of mineral matter in PM10 in Barcelona (Spain),