Relationships between metal contents in soil and grass contaminated by different anthropogenic sources

Superficial soil and grass (Lolium sp.) from seventeen locations affected by different human activities (mining, metal factory and traffic emissions) were taken in Gipuzkoa (North Spain) in 1998. Total metal contents in soil and grass and diethylenetriaminepentaacetic acid (DTPA)‐extractable metal from soil were determined by atomic absorption spectroscopy. In these soils different available metal levels, evaluated by chelating agent DTPA, were found and the following potential lability sequence was obtained: Cd > Pb > Cu > Zn > Mn > Ni > Fe > Cr. In order to check the associations between metal contents in soil (total or DTPA extractable) and total metal in grass, factor analysis was applied. The results suggested that DTPA could be used as a reliable chemical extractant for evaluating Cd, Zn, Ni and Cr availability from polluted soils to grass plants.