Platinum group elements contamination in soils: Review of the current state.

Platinum group elements (PGE: Ru, Rh, Pd, Os Ir, Pt) are rare metals with low abundance in the continental crust. The elements of the palladium subgroup of PGE (PPGE: Pt, Pd, Rh) have been exploited more and more over the last thirty years for their physicochemical properties such as high melting point, high resistance to corrosion, mechanical strength and ductility. This led to emerging environmental contamination in different media such as air, road dust, soil, sediment, vegetation, and snow. The aim of this review is to summarize the available data on soil contamination by PPGE and its potential environmental impact. In this paper, the environmental issue of PPGE is discussed with regard to their anthropogenic emission and fate, which includes speciation, possible transformations into bioavailable forms and toxicity. Soil contamination by PPGE is described taking into account urban and non-urban areas. The analytical determination process is also discussed.