Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulat... more Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event S1.
The aim of this survey was to assess metal concentrations in precipitation over the Aegean Sea an... more The aim of this survey was to assess metal concentrations in precipitation over the Aegean Sea and to identify possible source regions that contribute to their long-range transport to the northeastern Mediterranean. Total metal concentrations in 37 rainwater samples collected on the island of Lesvos showed a high variability depending mostly on the origin of the air masses influencing the rain events assessed by 4-day back trajectories. Concentrations of Al, Fe, Mn, Cu, Pb, Zn, Cr and Ni were rather similar to those found at other coastal sites in the Mediterranean basin, but Cd was significantly lower. The calculation of crustal enrichment factors of the metals along with the statistical analysis of the results showed that Saharan dust storms supply significant amounts of natural Al, Fe, Mn, Cr and Ni to the northern Aegean atmosphere, although some amounts of Cr and Ni are also contributed from anthropogenic sources. On the other hand, anthropogenic emissions largely determine Pb, Cu, Cd and Zn loads, although not all four metals follow the same enrichment and transportation pattern.
The occurrence of As was studied in groundwater used for human consumption and irrigation, in str... more The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos–Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range −1 in groundwater, 41.1–90.7 μg L−1 in thermal spring water and 0.4–13.2 μg L−1 in stream water, whereas As concentrations in stream sediments varied between 2.0–21.9 mg kg−1. Four out of 31 groundwater samples exceeded the EC standard of 10 μg L−1. The survey revealed an enrichment in both surface and groundwater hydrological systems in the northern part of the area (average concentrations of As in groundwater, stream water and stream sediment: 8.0 μg L−1, 8.8 μg L−1 and 15.0 mg kg−1 respectively), in association with the volcanic bedrocks, while lower As concentrations were found in the eastern part (average concentrations in groundwater, stream water and stream sediment: 2.9 μg L−1, 1.7 μg L−1 and 5.9 mg kg−1 respectively), which is dominated by ophiolitic ultramafic formations. The variation of As levels between the different parts of the study area suggests that local geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos–Lisvori does not affect the presence of As in groundwater and streams.
The emission of platinum group elements (PGEs) from automobile catalytic converters has led to ra... more 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.
Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulat... more Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event S1.
The aim of this survey was to assess metal concentrations in precipitation over the Aegean Sea an... more The aim of this survey was to assess metal concentrations in precipitation over the Aegean Sea and to identify possible source regions that contribute to their long-range transport to the northeastern Mediterranean. Total metal concentrations in 37 rainwater samples collected on the island of Lesvos showed a high variability depending mostly on the origin of the air masses influencing the rain events assessed by 4-day back trajectories. Concentrations of Al, Fe, Mn, Cu, Pb, Zn, Cr and Ni were rather similar to those found at other coastal sites in the Mediterranean basin, but Cd was significantly lower. The calculation of crustal enrichment factors of the metals along with the statistical analysis of the results showed that Saharan dust storms supply significant amounts of natural Al, Fe, Mn, Cr and Ni to the northern Aegean atmosphere, although some amounts of Cr and Ni are also contributed from anthropogenic sources. On the other hand, anthropogenic emissions largely determine Pb, Cu, Cd and Zn loads, although not all four metals follow the same enrichment and transportation pattern.
The occurrence of As was studied in groundwater used for human consumption and irrigation, in str... more The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos–Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range −1 in groundwater, 41.1–90.7 μg L−1 in thermal spring water and 0.4–13.2 μg L−1 in stream water, whereas As concentrations in stream sediments varied between 2.0–21.9 mg kg−1. Four out of 31 groundwater samples exceeded the EC standard of 10 μg L−1. The survey revealed an enrichment in both surface and groundwater hydrological systems in the northern part of the area (average concentrations of As in groundwater, stream water and stream sediment: 8.0 μg L−1, 8.8 μg L−1 and 15.0 mg kg−1 respectively), in association with the volcanic bedrocks, while lower As concentrations were found in the eastern part (average concentrations in groundwater, stream water and stream sediment: 2.9 μg L−1, 1.7 μg L−1 and 5.9 mg kg−1 respectively), which is dominated by ophiolitic ultramafic formations. The variation of As levels between the different parts of the study area suggests that local geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos–Lisvori does not affect the presence of As in groundwater and streams.
The emission of platinum group elements (PGEs) from automobile catalytic converters has led to ra... more 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.
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