Keywords: 
• road dust /
• PGEs /
• enrichment features

Abstract: Platinum group elements(PGEs)levels in road dust from Shanghai were measured,and their spatial variation and sources were discussed as well.Road dust samples were analysed by ICP-MS following aqua regia digestion.PGEs levels in all samples were above the average upper crust values,with concentrations of 27.68(61.05—4.50)ng·g-1 Rh,107.72(12.98—241.40)ng·g-1 Pd and 34.89(0.36—108.60)ng·g-1 Pt,respectively,Pd and Rh concentrations were in the middle level and Pt concentrations were lower,in comparison with international cities.Highest pollution occurred between inner ring and middle ring,while lowest values were presented from outer ring to suburb.The rank of PGEs levels in different type of roads was:Elevated Road(Including Ring Line)﹥Trunk Road﹥Secondary road﹥Expressway﹥Suburban road.Levels of the three elements showed strongly positive correlation.Preliminary results for the anthropogenic Rh,Pd and Pt emissions in Shanghai,based on dust samples,indicated a common traffic-related source of these metals.The average Pd concentration was higher than Pt and Rh,which differed from most previous studies.Meanwhile,the average PGEs ratios of road dust samples from Shanghai were inconsistent with Ely's result.These differences were contributed by the change of vehicle exhaust catalyst type.PGEs in these samples were not correlated with Pb and only Pt were correlated with Zn,though positive correlations with Cr and Cu were evident.This lack of statistically significant relationships can be explained by the fact that Pb and Zn are known as poisoning agents for autocatalysts.