Elevated heavy metal concentrations in top soils of an Aegean island town (Greece): total and available forms, origin and distribution

Abstract

Elevated heavy metal concentrations in urban top soils are principal indicators of environmental pollution; however, relative data on the heavy metal status in soils of Greek island towns, that are regional administrative centers and popular tourist destinations, are missing. A survey was conducted to examine heavy metal concentrations in the urban soils of Ermoupolis, the capital of Syros island and of the prefecture of Cyclades complex in the Aegean Sea. Total (aqua-regia extracted) and available (DTPA extracted) concentrations of Cu, Pb, Zn, Ni, Cr, Sn and Fe were determined in top soil samples collected from green areas and open spaces of the town and in surface samples from inland reference soils of the island. Mean values for the aqua-regia extracted fraction of Cu, Pb and Zn were 117, 155 and 440 mg kg(-1) respectively, up to four times higher than the respective mean values of the reference soils. Enrichment factors (EFs) for these metals indicated high accumulation in the urban top soils and the available to total concentration ratio of Cu, Pb, Zn and Fe was higher for the urban compared to the reference soils, suggesting differences in metal sequestration, resulting in higher metal availability in the urban soils. GIS analysis was used to visualize the spatial distribution of EFs of the studied heavy metals. Factor Analysis and Cluster Analysis, applied to aqua-regia and DTPA data sets, adequately elucidated the origin of metals grouped under each factor or cluster.

The spatial distribution pattern of heavy metal concentrations in urban soils — a study of anthropogenic effects in Berehove, Ukraine

“…heating systems) are possible risk factors and we have to know the level of pollution. Our results are in strong agreement with other authors [20,[63][64][65] who have studied different sized cities (without dominant industrial production but with a relevant traffic load) and reinforce the idea that generally there are moderate levels of pollution with possible local problems.…”

“…The publications regarding the heavy metal load of soils focus primarily on the large industrial centers and metropolises, and there are fewer papers investigating the situation in smaller cities and rural towns, even though similar problems may often arise in such places [20]. In their study, Chirenje et al [21] investigated the Pb contamination levels of two cities with different traffic rates and population densities (Miami, 370,000 and Gainesville, 95,000 inhabitants).…”

Concentrations of Available Heavy Metals in Mediterranean Agricultural Soils and their Relation with Some Soil Selected Properties: A Case Study in Typical Mediterranean Soils

“…This might be because increased pH's could thus favor the release of these metals by mobilizing the soil components in which they are retained. Although heavy metals are more weakly bound to soil particles in contaminated soils than in purely lithogenic ones, and are hence more readily mobilized [60][61][62]. The Cd, Cr, Pb, and Ni levels were correlated with soil carbonates, suggesting their presence in these soils in a form linked to carbonates [58,63].…”

Evaluating the effect of age and area of residence in the metal and metalloid contents in human hair and urban topsoils

“…indicators" (Massas et al, 2009 and Ti; and zones II and IV presented the smaller levels of those metals that shown a dependency 187 with the area of residence. This result was unexpected as the zone I had a higher density of green 188 areas, and therefore a lower density of traffic and industries than the other zones ( Figure 1).…”