Heavy metal contamination analysis of roadsoils and grasses from Gipuzkoa (Spain)

Superficial soil samples and grasses from different locations close to roads varying traffic flow and distance were analysed. The heavy elements: Cd, Cr, Cu, Fe, Mn, Ni, Fb and Zn were determined by atomic absorption spectrometry. The most notorious point was located near to A-8 highway; in that location Zn, Pb and Cu showed higher levels than critical soil concentrations. For Cd, Cu, Pb and Zn highly significant correlations between total contents in soils and DTPA extractable levels were found. Also, for these metals, significant correlations between metal levels in soils and contents in grass were obtained. Factor analysis was applied to heavy metal data and the association among Cd, Pb and Zn seem to have the same origin pollution source, motorized traffic.