Efstratios Kelepertzis

Urban soil geochemistry in Athens, Greece: The importance of local geology in controlling the distribution of potentially harmful trace elements

Understanding urban soil geochemistry is a challenging task because of the complicated layering of the urban landscape and the profound impact of large cities on the chemical dispersion of harmful trace elements. A systematic geochemical soil survey was performed across Greater Athens and Piraeus, Greece. Surface soil samples (0-10cm) were collected from 238 sampling sites on a regular 1×1km grid and were digested by a HNO3-HCl-HClO4-HF mixture. A combination of multivariate statistics and Geographical Information System approaches was applied for discriminating natural from anthropogenic sources using 4 major elements, 9 trace metals, and 2 metalloids. Based on these analyses the lack of heavy industry in Athens was demonstrated by the influence of geology on the local soil chemistry with this accounting for 49% of the variability in the major elements, as well as Cr, Ni, Co, and possibly As (median values of 102, 141, 16 and 24mg kg(-1) respectively). The contribution to soil chemistry of classical urban contaminants including Pb, Cu, Zn, Sn, Sb, and Cd (medians of 45, 39, 98, 3.6, 1.7 and 0.3mg kg(-1) respectively) was also observed; significant correlations were identified between concentrations and urbanization indicators, including vehicular traffic, urban land use, population density, and timing of urbanization. Analysis of soil heterogeneity and spatial variability of soil composition in the Greater Athens and Piraeus area provided a representation of the extent of anthropogenic modifications on natural element loadings. The concentrations of Ni, Cr, and As were relatively high compared to those in other cities around the world, and further investigation should characterize and evaluate their geochemical reactivity.

Investigating the sources and potential health risks of environmental contaminants in the soils and drinking waters from the rural clusters in Thiva area (Greece).

The present study investigates the possible influence of human activities on metal loadings of topsoil in a typical small rural city in central Greece and the chemical quality of tap water in surrounding villages. Furthermore, the study aimed to examine potential health risks of naturally enriched heavy metals to exposed population taking into account the soil and drinking water as exposure pathways. The mean concentrations of Ni, Cr, Co, Mn, Pb, Cu, Zn and Cd in the soil were 1777, 285, 99, 946, 30, 26, 78 and 0.67 mg/kg respectively. Combination of pollution indexes based on local reference background soils and statistical analyses (correlation analysis, cluster analysis and principal component analysis) revealed that anthropogenic activities have not modified the natural soil chemistry at least in a large scale. High Hazard Quotient (HQ) values for children were estimated for Ni, Cr and Co based on total metal concentrations for the soil ingestion route (9.26E-01, 9.75E-01 and 3.45E+00 respectively). However, evaluation of HQs based on published bioaccessible concentrations suggested that the population groups would not likely experience potential health risks as a result of exposure to contaminated soils. Concentrations of Cr(VI) in tap waters were within the allowable limits. However, the risk assessment model revealed that local residents (adults) of Eleonas and Neochori villages are at some carcinogenic risks considering lifetime ingestion of water (potential cancer risks 2.05E-04 and 1.29E-04 respectively). Despite the uncertainties accompanying these procedures and the great deal of debate regarding the human carcinogenicity of Cr(VI) by the oral route, results of this study drive attention to remediation measures that should include epidemiological studies for the local population.

Heavy Metals in Agricultural Soils of the Mouriki-Thiva Area (Central Greece) and Environmental Impact Implications

The heavy metal content of 51 surface soil samples from the agricultural region of Mouriki-Thiva (central Greece) was investigated by a combination of mineralogical (X-ray diffraction and scanning electron microscopy) and geochemical (aqua regia and 0.5 M HCl extractions) methods in order to determine the levels of contamination, as well as the origin, distribution and mobility of selected metals. The geology of the area includes ultrabasic rocks, and consequently the soils have anomalous values in Ni (621-2639 mg/kg) and Cr (134-856 mg/kg). Whereas Cr is mainly hosted in the crystal structure of chromite, Ni is primarily mobilized from olivine and serpentine. Nickel, and to a lesser extent Cr, were also found to be absorbed in Fe oxides. The results of a single 0.5 HCl leach revealed significant differences in the mobility and potential bioavailability of Ni and Cr in representative soil samples; Nickel is substantially more labile, and as a result a potential amount of this metal is readily available to the plants. The whole area is heavily contaminated by Ni and Cr and consequently the monitoring of the agricultural products of the region for their heavy metal content is strongly recommended.

Evaluation of the sources of contamination in the suburban area of Koropi-Markopoulo, Athens, Greece.

Heavy metal concentrations were monitored in agricultural soils and irrigation groundwaters of Koropi–Markopoulo area, a representative agricultural suburb in Athens, Greece, aiming at the identification of the sources of contaminants. Multivariate analyses of geochemical data demonstrated that agricultural practices and industrial activities considerably affected the quality of both environmental compartments. The levels of Ni, Cr, Co, Mn and Fe in agricultural soils were associated with geological parent materials whereas Pb, Zn and Cu mainly originated from anthropic activities. Referring to groundwaters, individual major anions and cations (K+, Na+, Ca2+, Mg2+, NO3−, SO42−, Cl−) were influenced by various natural and anthropogenic factors whereas Ni, Cr, Cu and Zn were controlled by industrial and agronomic activities. The identification of the sources of contaminants in soil and groundwater environments is a valuable basis for encouraging mitigation strategies preventing further quality degradation.

Availability of geogenic heavy metals in soils of Thiva town (central Greece).

Potentially toxic metals in the urban chemical environment impose risks to both ecosystem and human health. Here, we evaluate the labile pools and availabilities of non-anthropogenic Ni, Cr, Co and Mn in soil samples from Thiva town (central Greece) and investigate their associations with common soil properties and geochemical data obtained by the aqua regia and single selective dissolutions. Experimental work included the initial application of the sequential extraction protocol proposed by the European Community Bureau of Reference and chemical extractions with ethylenediamine tetraacetic acid solution and a modified physiologically based extraction test with the aim to obtain the operationally defined fractions of plant availability and human bioaccessibility, respectively. The leachate results demonstrated that despite the significant contribution of residual metal species especially for Ni and Cr, the studied serpentine soils provide chemically labile pools for all the considered elements. Nickel was found to be the most available metal with the order being Ni > Cr ∼ Co ∼ Mn for plant uptake and Ni > Cr > Co ∼ Mn for human bioaccessibility. The aqua regia extractable concentrations are not predictors of elemental availabilities except for Ni bioaccessible data interpreting however only a moderate percentage of the total variance. The incorporation of basic soil properties (mostly total organic carbon), geochemical data for the major elements Ca, Mg and Fe and ammonium oxalate extractable Cr significantly improved the estimations for individual elements entailing the strong influence of the chemistry and mineralogy of soil materials to the release of focus metals from the soil matrix. This study provides for the first time bioaccessible data for serpentine-derived soils that are more realistic for evaluating potential adverse effects on the human health.

Insights into the chemical partitioning of trace metals in roadside and off-road agricultural soils along two major highways in Attica’s region, Greece

We report in this study the magnetic properties and partitioning patterns of selected trace metals (Pb, Zn, Cu, Cd, Ni) in roadside and off-road (>200m distance from the road edge) agricultural soils collected along two major highways in Greece. Sequential extractions revealed that the examined trace metals for the entire data set were predominantly found in the residual fraction, averaging 37% for Cd up to 80% for Cu. Due to the strong influence of lithogenic factors, trace metal pseudototal contents of the roadside soils did not differ significantly to those of the off-road soils. Magnetic susceptibility and frequency dependent magnetic susceptibility determinations showed a magnetic enhancement of soils; however, it was primarily related to geogenic factors and not to traffic-derived magnetic particles. These results highlight that in areas characterized by strong geogenic backgrounds, neither pseudototal trace metal contents nor magnetic properties determinations effectively capture traffic-related contamination of topsoils. The vehicular emission signal was traced by the increased acid-soluble and reducible trace metal contents of the roadside soils compared to their off-road counterparts. In the case of Cu and Zn, changes in the partitioning patterns were also observed between the roadside and off-road soils. Environmental risks associated with agricultural lands extending at the margins of the studied highways may arise from the elevated Ni contents (both pseudototal and potentially mobile), and future studies should investigate Ni levels in the edible parts of plants grown on these agricultural soils.

Heavy Metals Baseline Concentrations in Soft Tissues of Patella Sp. From the Stratoni Coastal Environment, Ne Greece / Bazowy Poziom Zanieczyszczeń Metalami Ciężkimi W Tkankach Miękkich Patella Sp. Występujących W Przybrzeżnych Obszarach Stratoni, Grecja

Abstract Species of the limpet Patella sp. were collected from a typical control coastal site (Artemida) and a metal contaminated marine environment (Stratoni), situated in Greece. The soft tissues were analyzed for their heavy metal (Pb, Zn, Mn, Cu, Ni, Cr) content by flame atomic absorption spectroscopy. High Pb, Zn and Cu concentrations were determined in limpet samples from Stratoni, which can be attributed to geological-mineralogical factors due to the natural heavy metal elevated substrate of the broader mineralized area. In contrast, concentrations of Mn, Ni and Cr in both areas are comparable to those reported for other non-polluted geographical regions of the Mediterranean area. Considering the refurbishment of the Stratoni port that will accompany the new large scale mining operations, these results provide a preliminary baseline metal level in these organisms, by which future local changes could be assessed. It is suggested that the species of Pattella sp. are appropriate to be used for biomonitoring research and should be included in routine monitoring programs regarding the Stratoni marine ecosystem. Further studies of metal levels in limpets of Patella sp. from the Stratoni area including the investigation of the possible effects of seasonal changes on metal concentrations and distribution are required. Abstrakt W celu oceny zanieczyszczenia metalami ciężkimi przybrzeżnych wód morskich Grecji mięczaki z gatunku skałoczepów Patella sp. zostały zebrane na zanieczyszczonym obszarze (Stratoni) oraz w pobliżu typowego miejsca kontrolnego (Artemida). Metodą płomieniowej atomowej spektroskopii absorpcyjnej zbadano stężenia metali ciężkich (Pb, Zn, Mn, Cu, Ni i Cr) w tkankach miękkich. Wysokie stężenia Pb, Zn i Cu oznaczono w próbkach skałoczepów ze Stratoni, co może wynikać ze składu geologiczno-mineralogicznego podłoża. W przeciwieństwie do tego, stężenie Mn, Ni i Cr w próbkach zebranych na obu obszarach są porównywalne ze stężeniami opisanymi dla niezanieczyszczonych regionów śródziemnomorskich. Zważywszy na remont portu Stratoni, któremu będą towarzyszyły prace górnicze, wyniki te stanowią wstępną ocenę poziomu zanieczyszczenia metalami tych organizmów, co umożliwia ocenę przyszłych, lokalnych zmian. Przypuszczalnie, gatunki Pattella sp. są odpowiednie do wykorzystania w badaniach biomonitoringowych i powinny zostać uwzględnione w badaniach biomonitoringowych morskiego ekosystemu Stratoni. Wymagane jest prowadzenie dalszych badań zawartości metali w skałoczepach Pattella sp. z obszaru Stratoni oraz ocena sezonowych zmian stężeń i ich rozkładów.

Factors controlling major ion and trace element content in surface water at Asprolakkas hydrological basin, NE Chalkidiki: Implications for elemental transport mechanisms

Chemical characteristics of stream water at Asprolakkas hydrological basin were determined in February 2009 in order to examine the main factors controlling the hydrogeochemistry of the drainage system. A total of 20 surface water samples were collected and analyzed for the major ions K, Na, Ca, Mg, HCO3, SO4 and the trace elements Fe, Pb, Zn, Mn, Cu, Ni, As, Sb, Mo and Ba. The application of R-mode factor analysis revealed that the polymetallic carbonate replacement type sulfide deposits, together with the porphyritic intrusions and the associated porphyry copper style mineralization, occurring in the studied area, impose fundamental control on the water chemistry. A third influencing factor includes the parameters As and HCO3 and is attributed to the competitive behavior of As and bicarbonate ions, for filling in available absorption space on Fe(III) oxides. SEM-EDS methods, performed on retained filters from the filtration of representative water samples, showed that Pb is mainly transported by fine particulate matter. The chemical elements Mn, Zn, Mo and Sb are predominantly present as dissolved free ions, and correlate strongly with the electrical conductivity of the water samples.