Lead and Cadmium Changes in Soil and Canola at Saveh-Hamedan Roadside

Vehicles are of the sources of heavy metals such as lead and cadmium in the roadsides. The present study was carried out in order to investigate، changes of lead and cadmium levels in the soil and Canola caused by vehicle traffic at Saveh-Hamadan road on the basis of factorial design with complete randomized blocks. Soil and plant samples were collected at the distances of 5، 10، 20، 40، 80 and 160 meters from the road edge. The amounts of cadmium and lead were measured in root، shoot and seed of the plant and soil. The results showed that the amount of the lead decreased with increasing the distance from the road in both of the soil and plant. So that، the highest amounts of the total and absorbable lead belonged to the soil samples with the closest distance (5m) from the road، that were 38. 86 and 3. 79 mg kg-1، which showed an increase of 3. 68% and 8. 59% compared to those at the distance of 160 meters respectively. The maximum amount of soil total cadmium was 3. 62 mg/ kg-1 observed at a distance of 40 meters. Also the levels of accumulation of lead and cadmium in the shoot were more than those in the root and seed sections. While the roadside soil was contaminated with cadmium، the plants were contaminated with both lead and cadmium. Therefore، livestock feeding from these plants threatens their animals and finally human health. The results of this study may be used in planning land use along the road، transportation management and urban traffic control.