Survey of the Distribution and Time-Dependent Increase of Platinum-Group Element Accumulation Along Urban Roads in Ioannina (NW Greece) George Z. Tsogas & Dimosthenis L. Giokas & Athanasios G. Vlessidis & Maria Aloupi & Michael O. Angelidis Received: 4 September 2008 / Accepted: 24 November 2008 / Published online: 16 December 2008 # Springer Science + Business Media B.V. 2008 Abstract The emission of platinum group elements (PGEs) from automobile catalytic converters has led to rapid increases in Pt, Pd, and Rh concentrations in roadside media. This article represents the first systematic study in Greece to assess PGE levels in road dust and roadside soil and their temporal variation on a seasonal basis over a 12-month period. Road dust and roadside soil samples were analyzed by graphite furnace atomic absorption spectrometry following microwave digestion. Concentrations of PGE in all samples were above the average upper crust values and local background levels, with maxi- mum values of 306.4 ng/g Pt, 18.2 ng/g Pd, and 64.6 ng/g Rh in road dust and 225 ng/g Pt, 14.0 ng/g Pd, and 49.5 ng/g Rh in roadside soil. PGE ratios were not consistent with known catalytic converter com- position throughout the sampling period reflecting the high emission of Rh from new catalytic converters. Spatial variations were influenced by various factors like driving style, matrix composition, diurnal change in traffic volume, and climatic conditions. With regard to seasonal variations, systematic changes in the temporal distribution of PGE levels were observed and followed a similar pattern between the two matrices. Except PGEs, Pb levels were determined, since it has been a typical indicator of vehicle-derived environmental lead pollution. The data indicate that despite the use of unleaded gasoline, traffic-related sources of Pb that induce levels above the local background have not been eliminated. Keywords Urban environmental pollution . Platinum group elements . Road dust . Roadside soil . Multidimensional scaling . Discriminant analysis 1 Introduction Catalysts for automotive traction implemented in all new cars registered in the EU since 1993 contain Pt, Pd, and Rh (platinum-group elements, PGEs) for conversion of gaseous pollutants into more innocuous substances. However, it is now well established that attrition of platinum group elements (PGEs) from the catalyst may cause its subsequent release into the environment (Palacios et al. 2000). For this reason, there is increasing concern about the release of these elements especially in large cities with heavy vehicle traffic (Petrucci et al. 2000; Jarvis et al. 2001) and their potential negative impacts on humans and other living organisms (Bocca et al. 2004). Up to date, a number of studies have been devoted to the investigation of PGEs in roadside samples. Two Water Air Soil Pollut (2009) 201:265–281 DOI 10.1007/s11270-008-9943-1 G. Z. Tsogas : D. L. Giokas (*) : A. G. Vlessidis Department of Chemistry, University of Ioannina, 45100 Ioannina, Greece e-mail: dgiokas@cc.uoi.gr M. Aloupi : M. O. Angelidis Department of Environment, University of the Aegean, 81100 Mytilene, Greece