Chromium and Nickel distribution in sediments of a coastal area impacted from metallurgical activities: the case of the Larymna Bay

In the present study, the distribution of Cr and Ni was investigated in the surface sediments from the Larymna Bay (Northern Evoikos Gulf) and in metallurgical slag samples discharged in the marine environment. The results were compared to concentrations of Cr and Ni in parent rocks that outcrop extensively in the catchment area of N. Evoikos in order to distinguish natural and anthropogenic sources of these two elements. Elevated concentrations of Cr and Ni as well as high values of magnetic susceptibility were determined in all samples. Low leachability was determined for Cr since chromite is the major crystalline phase of Cr in the samples analyzed whereas higher leachability was observed for Ni

Geochemical processes of trace metals in fresh–saline water interfaces. The cases of Louros and Acheloos estuaries

Fresh–saline water interfaces are sites of major transformations on the speciation and the distribution of trace metals, through complex processes. The present chapter considers trace metal geochemical processes at fresh–saline water interfaces of representative Greek riverine systems, namely of those of the perennial medium-sized Louros River and the big and highly fragmented Acheloos River. Dissolved and particulate metals, as well as metal fractions in the sediments, are considered in combination with physicochemical parameters, and mineral magnetic measurements are used for tracing the origin of particle populations (lithogenic, anthropogenic, authigenic), and their compositional alterations during their passage from the rivers, through the interfaces, to sea. The interfaces of the two systems have distinct characteristics both on a spatial and a temporal scale, thus allowing for a diversity of trace metal behaviour patterns to emerge. In the small, perennial Louros system, trace metals are trapped within the thin, yet stable salt wedge. In the heavily fragmented Acheloos system, variations of the water and sediment discharges have moved the active interface landwards, where due to the reduction of dilution effects by inert, detrital particles, the fingerprint of the authigenic and anthropogenic component of trace metals has become more pronounced. The results of the research carried out in the two distinctive fresh–saline water interface systems are important not only in order to enlighten us about the geochemical processes in nature, but also in order to provide the necessary knowledge to properly manage these systems for the benefit of the environment and the sustainable development of the impacted areas. © 2016, Springer International Publishing AG

Polycyclic aromatic hydrocarbons (PAHs) in marine sediments of the Hellenic coastal zone, eastern Mediterranean: Levels, sources and toxicological significance

Purpose: Polycyclic aromatic hydrocarbons (PAHs) are widespread in sediments, particularly near areas of intense human activities. Due to their mutagenic and carcinogenic behaviour, PAHs are classified as priority contaminants to be monitored in environmental quality control schemes. The purpose of this study was to determine the levels of PAHs in major coastal areas of Greece that receive various pressures, investigate their sources and evaluate their potential toxicity by comparison against effects-based Sediment Quality Guidelines (SQG). Materials and methods: Forty-one sediment samples were collected from four areas of the Hellenic coastline. PAH concentrations were determined by GC-MS, after Soxhlet extraction and fractionation by silica column chromatography. Source apportionment was conducted by isomeric ratio diagnostic criteria. The mean quotient Effects Range-Median (m-ERM) was used to evaluate the potential of adverse effects posed to benthic organisms. Results and discussion: The levels of PAHs were found to vary widely from 100 to more than 26,000 ng g-1. The highest levels were found in the close vicinity of an alumina production plant in the Gulf of Corinth. High levels of PAHs were also found at a few sites in each of the areas studied, close to a nickel production plant (North Evoikos Gulf), at the rainwater and wastewater outfalls of the great urban areas of Athens and Thessaloniki and at the industrialized area of Elefsis Bay (Saronikos Gulf). At the most contaminated sites PAH had a pyrolytic origin. Comparison of PAH levels to the SQG indicated that less than 15% of the sites studied have an intermediate probability (24-49%) of being toxic. Conclusions: In general, discrete point sources were identified as the major contributors of PAH contamination in the Hellenic coastal zone. Therefore, source control measures should be considered for protecting, or restoring, sediment quality, particularly in areas that support a diversity of anthropogenic activities (e. g. fishing, tourism, industry). © 2011 Springer-Verlag

Heavy Metals in Soil and Sand from Playgrounds of Çanakkale City (Turkey), and Related Health Risks for Children

Children spend most of their time in playgrounds and, in parallel, constitute the social group most sensitive to contaminants. Here, we present the results of a comparative study of heavymetal contents between soils and sand from sandboxes obtained from playgrounds of Çanakkale city. Average contents of soils followed the order of iron (Fe) (12,901 mg kg−1) > manganese (Mn) (475 mg kg−1) > zinc (Zn) (58 mg kg−1) > copper (Cu) (28 mg kg−1) > nickel (Ni), chromium (Cr) (21 mg kg−1) > lead (Pb) (18 mg kg−1). Sand had lower contents, however, due to the reduction of particles size through prolonged use, and accumulation of Fe/Mn (oxyhydr)oxides on sand grains tended to diminish the differences between soils and sand. Through chemometric analysis, Cr and Ni were found to have a lithogenic origin, while the rest of metals were related to anthropogenic activities. Spatially, heavy-metal contents followed the pattern of the city’s sprawl. Risk estimates on children’s health showed that ingestion was the most important exposure route, followed by dermal contact and inhalation. Exposure of children to sand was of similar importance to that of soils. These findings are significant, as the contamination of sand has not yet received much attention compared to the soil of playgrounds. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Linking environmental magnetism to geochemical studies and management of trace metals. Examples from fluvial, estuarine and marine systems

Among the diverse research fields and wide range of studies encompassed by environmental magnetism, the present work elaborates on critical aspects of the geochemistry of trace metals that emerged through years of original research in a variety of environmental compartments. This review aims at sharing the insights gained on (a) tracing metal pollution sources; and (b) identifying processes and transport pathways from sources to depositional environments. Case studies on the Elefsis Gulf (Greece) and the Gulf of Lions (France) demonstrate the potential of combined magnetic measurements and chemical analysis to trace pollution signals resulting from land-based sources and atmospheric deposition. Case studies on estuarine environments, namely the Louros, Acheloos, and Asopos Estuaries (Greece), address modes of trace metal behavior under the influence of different hydrological regimes and elucidate in situ processes within the transitional estuarine zone, that define their ultimate fate. As sources, transport pathways, and processes of trace metals are fundamental in environmental management assessments, the involvement of magnetic measurements in the policy cycle could facilitate the development and implementation of appropriate regulatory measures for the integrated management of river basins, coastal, and marine areas. © 2014, by the authors; licensee MDPI, Basel, Switzerland

Assessment of heavy metal contamination and mineral magnetic characterization of the Asopos River sediments (Central Greece)

The content and distribution of heavy metals in sediments of the intermittent and contaminated Asopos River, located in Central Greece, was assessed by means of total dissolution, dilute acid and sequential extraction procedures. Mineral magnetic properties were used as proxy parameters of transport mechanisms of land-derived material to the sea. The combination of enrichment factors estimated against local background levels and the levels of labile metals revealed that surface sediments are enriched in Cu, Cd, Ni and Cr. The low flow of the system allows particles and organic matter to accumulate in the estuarine shallow " pools" where they undertake a series of redox reactions, authigenic formation, etc. The most fine of these particles, which are metal rich, are transported to relatively long distances off the Asopos River mouth, even under low energy conditions, converting the system to a secondary source of pollution for the adjacent marine environment. © 2010 Elsevier Ltd

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 (>200 m 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. © 2016 Elsevier Inc

Geochemistry of major and trace elements in surface sediments of the Saronikos Gulf (Greece): Assessment of contamination between 1999 and 2018

The Saronikos Gulf receives pressures from the most urbanized and industrialized areas in Greece, the Athens metropolitan area and Pireaus port, and as such, it is considered as a hot spot of pollution in the Eastern Mediterranean Sea. Decades after policies aiming to achieve clean seas have been introduced and implemented, it is currently relevant to evaluate their impact on the environmental quality. Here we propose a methodology for this topical issue and we assess the distribution of major and trace elements using a 20 year (1999–2018) sedimentary record, and determine the current status, as well as contamination trends. The proposed synthesis of methods is outlined by the following major steps: establishment of background levels from dated cores, calculation of Enrichment Factors (EFs) and the multi-elemental, Modified Pollution Index (MPI), and assessment of temporal trends of MPI in a sub-regional scale. Copper, Zn, and Pb exhibited the highest EFs, mostly observed in the Elefsis Bay, the Inner sector of the Gulf, and the area parallel to the western Attica coast. The MPI classified the latter areas as moderately-heavily to severely polluted. Decreasing trends were detected in the industrialized Elefsis Bay, and were attributed to the decrease of land-based metal loads. No trends were detected in the other sub-regions, highlighting the need for intensifying efforts to abate pollution by designing management plans towards the reduction of metal contamination in the Saronikos Gulf. Finally, the present study illustrates that multi, regionalized background levels are necessary for effectively resolving elemental variations, particularly in the presence of metal-rich lithological complexes within the catchment areas. This finding should be taken into account when the background levels and background assessment levels are established for the Eastern Mediterranean's sub-regional seas within the framework and implementation of the EU's Marine Strategy Framework Directive. © 2020 Elsevier B.V

Dataset on the major and trace elements contents and contamination in the sediments of Saronikos Gulf and Elefsis Bay, Greece

Coastal marine sediments receive intensive stress from urbanization and industrialization, which is manifested by increased contents of heavy metals and organic pollutants. Saronikos Gulf and the small embayment of Elefsis, stretch along the coast of the greater Athens and Pireaus port, the most urbanized and industrialized areas in Greece. Here we present the data of a 20-year geochemical record on grain-size, organic carbon, and major and trace elements contents of the Saronikos Gulf sediments. A total of 216 sediment samples were collected within the period of 1999–2018 from the four sub-sectors of the gulf, namely, the Elefsis Bay, the Inner, Outer, and Western (Megara and Epidavros basin) Saronikos Gulf. Additionally, at least one core was obtained from each sub-sector. Sediments deposited at pre-industrial periods were recognized by 14C and 210Pb dating, and served for establishing regionalized background levels of metals. Factor analysis was conducted to reveal the inter-parametric relationships, thus their common sources, as well as transport and deposition pathways. Then, Enrichment Factors and the multi-elemental Modified Pollution Index (MPI) were calculated to assess the current environmental status of the sediments. Data of sampling sites with at least a five-year record, were assessed for temporal trends, to explore whether sustained, increasing or decreasing trends of the MPI are observed. The dataset and analyses presented here support the research article entitled Geochemistry of major and trace elements in surface sediments of the Saronikos Gulf (Greece): assessment of contamination between 1999 and 2018 [1]. © 2020 The Author

Settled bus dust as a proxy of traffic-related emissions and health implications of exposures to potentially harmful elements

Limited information on potentially harmful elements (PHEs) contents of settled bus dusts and associated health risks for commuters is available in the literature. Here, magnetic measurements were combined with geochemical analysis to provide insight into the origin and occurrence of PHEs (Cr, Cu, Fe, Hg, Ni, Pb, and Zn) in settled bus dust samples from the urban area of Athens, Greece. Microscopic observations showed the abundance of angular and spherical Fe-rich particles, carbonaceous spherules, and a variety of Ba, Cu, Pb, and Zn-containing particles, typically deriving from vehicular emissions. Settled bus dust was magnetically enhanced in relation to the road-verge Athens soil, and exhibited a ten-fold (Hg), eight-fold (Zn, Cu), and four-fold (Pb) enrichment. The oral bioaccessibility of PHEs followed the order Zn > Pb > Cu > Cr > Ni > Fe > Hg. Potential adverse health risk effects through ingestion, inhalation of particles and Hg vapors, and dermal contact were assessed using the U.S. EPA risk assessment model. Potential cancer risk for drivers and children (1–6 years old), commuting four days per week for 120 min per day, were above the regulatory levels of 1 × 10−4. Non-cancer risks may also arise, mainly because of inhalation of Hg vapors. Despite the intrinsic uncertainty related mainly to toxicity data and exposure parameters, the risk assessment helped to prioritize Cr and Hg as the elements of major concern. © 2020 Turkish National Committee for Air Pollution Research and Contro