Sources and factors influencing distribution of Pb in soils in the vicinity of crossroads in the city of Bratislava

With an abrupt rise of numbers of vehicles there is a certain risk of polluting not only the city environment but also distant natural locations. This work documents the distribution of Pb in soils in the vicinity of crossroads in Bratislava. We found that mean and median concentrations of Pb are 54.17 mg kg^-1 and 38.84 mg kg^-1. The influence of traffic intensity and age of crossroads were evaluated and found that both of these factors have significant impact on higher content of Pb in roadside soils, although the factor of age has been proved to be more statistically significant. It was also found that Pb content positively correlates with total organic carbon measured in the same soil samples (Sp. r=0,335; p<0,001). Stable isotope composition revealed Pb originating from leaded gasoline makes up to 60 % of soil lead. It was also found that coal combustion and other non exhaust sources can be a significant source of Pb in soils. (authors)