Concentrations of pt, pd and rh in soil and vegetation: A review

Abstract

Hot exhaust gases that pass through the automotive catalyst cause emissions of platinum group of elements (PGE): platinum (Pt), palladium (Pd) and rhodium (Rh) into the environment. This review will give state of the art of PGE worldwide in soil and vegetation, and in the analytical methods by which their concentration is determined. Previous research in the world related to the levels of PGE in the environment shows that these elements can be found in all components of the environment (air, water, soil, plants, road dust, ash, sewage sludge and shellfish). The results of research in other countries indicate that Pt, Pd and Rh occur in elevated concentrations in soil and plants in urban areas (along roads) compared to rural areas. PGE concentrations in soil and plants are higher in the vicinity of the roads and at higher traffic intensity. There was also noted a trend of decreasing concentrations with soil depth. In addition, variations of PGE concentration in soils is also influenced by the season (spring, autumn), length of exposure to PGE emission (longer exposed soil having more PGE concentrations) and driving speed.