Lead contamination in the roadside soils of Slovenia

The level of lead contamination along the roadway Ljubljana to Zagreb was established in 184 soil samples. The samples were taken from two depths (0-5 cm and 15-20 cm) and at different distances from the roadway. The influence of terrain morphology, prevailing winds, geological parent material and type of vegetation was estimated. Heavy traffic is confirmed as main source of lead contamination (average enrichment factor 17) in soils. The highest lead accumulation is localised in the top soil layer and within 10 m from the roadside. Contamination with lead is more pronounced in soil samples from cuttings and slopes than in soils from plains and mounds. Soils derived from carbonate rocks contain higher lead concentration than those derived from other parent material.