Time-dependent increase of traffic-emitted platinum-group elements (PGE) in different environmental compartments

During the past decade, the traffic-related emission of Pt, Ph, and Pd has strongly increased resulting in growing concentrations in specific environmental areas. To distinguish different aspects of time-dependent development, PGE (platinum-group elements) concentrations and element ratios in urban dust; road-dusts, soil, and sewage sludge samples collected over the past decade were determined. The short-term variation of PGE concentrations and element ratios in road dust is due to wind and rain, whereas the long-term trend reflects the changing proportions of PGE used for converter production. At a typical urban site the daily deposition rate of Pt in airborne dust is up to 23 ng m(-2). In soil, the total input of PGE has been accumulated since the introduction of converter technology. Because of very low background values, this contamination results in rapidly increasing PGE concentrations, showing multiplied values over a period of 2 years at a typical highway site. The integration of these data permits an estimate of the total accumulation of PGE and mean emission rates that are significantly higher than experimental results from stationary motor experiments. Runoff contributes to the composition of sewage but seems to be less important, compared to other sources, in total PGE input into urban sewage sludge.