Survey of the Distribution and Time-Dependent Increase of Platinum-Group Element Accumulation Along Urban Roads in Ioannina (NW Greece)

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 maximum 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 composition 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.

     

The Significance of Coarse Sediments in Metal Pollution Studies in the Coastal Zone

The role of coarse material (sand fraction) in the distributionof metals in polluted marine sediments was investigated in theharbors and the coastal zone of Mytilene, island of Lesvos,Aegean Sea. It was found that sand fraction contains a relatively significant proportion of the anthropogenic metalsand therefore it cannot be neglected in metal pollution studiesof coastal sediments. Also the distribution of the anthropogenicmetals (Cd, Cu, Pb and Zn) in both silt+clay and sand fractionsfollow the same pattern indicating similar pollution sources. In the bulk sediment (clay + silt + sand fraction) all anthropogenic metals had a significant amount (> 50%) in theacid-extractable (and potentially bio-available) fraction.     

Total Metal Concentrations in Atmospheric Precipitation from the Northern Aegean Sea

Water, Air, & Soil Pollution - This paper presents the development of a filtered stepwise clustering (FSC) method for facilitating the pump-and-treat (PAT) designs in groundwater remediation...