UPTAKE OF TRAFFIC-RELATED HEAVY-METALS AND PLATINUM-GROUP ELEMENTS (PGE) BY PLANTS

The distribution of the platinum group elements (PGE) caused by traffi c emissions from autoexhaust catalysts has been determined in soils an d different types of plants. The plants (spinach, cress, phacelia, sti nging nettle) were cultivated on different soils collected from areas adjacent to a German highway and on uncontaminated sandy and clayey so ils. The main result of the experiments was a measurable transfer of P GE from contaminated soil to plants. Following the definition of Sauer beck (1989), Pt, Rh and Pd transfer coefficients are within the range of immobile to moderately mobile elements, such as Cu. The transfer co efficient decreases from Pd > Pt greater than or equal to Rh, palladiu m therefore is the most biologically available of this element group. (C) 1998 Elsevier Science B.V.