Search

In this study, site-specific natural background levels (NBLs) were determined for 18 elements (Al, As, Be, Cd, Co, Cu, Cr, Fe, Hg, K, Mn, Mo, Ni, Pb, Tl, U, V, and Zn) in two sediment cores collected offshore the Bagnoli-Coroglio brownfield site (Gulf of Pozzuoli, southern Italy) to accurately assess the degree of contamination and the historical trends in Heavy Metals (HMs) enrichment. This objective was pursued taking in account the high temporal and spatial variability of the geochemical properties of the area due to the local geothermal activity. Moreover, the temporal variation of Polycyclic Aromatic Hydrocarbons (PAHs) was investigated.226Ra was used as an extraordinary marker to confirm 210Pb dating. It especially allowed defining the geochronological framework of the sediment core closer the brownfield up to around 1500, providing compelling support to correlate the investigated elements’ occurrences with natural geogenic dynamic. Sediment samples were accurately dated and analyzed for chemical and particle size composition. The contamination factor (Cf) and the pollution load index (PLI) showed very high enrichment of Cd, Cu, Hg, Pb, and Zn. The contamination profiles of HMs and PAHs follow the same pattern in both sediment cores, increasing from deep to upper layers. The highest contamination levels for HMs and PAHs were observed between 10 and 30 cm, corresponding to the periods of most intense industrial activity. Decreasing trends of pollutants were observed in the surface layers (0–10 cm), probably affected by a natural attenuation process due to the cessation of industrial activities.

In this study we propose, a multi-step strategy of selection and characterization of long-term dataset of contaminant concentrations in different environmental matrices (i.e., water and sediment). Starting from a high quality and homogeneous dataset of chemical parameters, a selection of a usable refined dataset followed by statistical characterization and hazard assessment was performed. The database of chemical contamination data from monitoring activities in the coastal marine water area of the Campania Region (Italy) produced by the Regional Agency for Environmental Protection of Campania (ARPAC) between 2013 and 2019 was utilized. Descriptive and multivariate statistics were applied to the extracted data subset to describe spatial variability and to investigate the relationships between matrices and contaminants. In addition, the impact on the sediment matrix was considered using the contamination factor (Cf), the sediment quality guidelines (SQG), and the probability of exceedance (PoE) of given thresholds for metals and organic compounds. The results highlighted the main anthropogenic pressures between the Gulf of Pozzuoli and the Gulf of Napoli, and the potential hazard posed in particular by metals (i.e., Pb, C, and Hg), TBT, and PAHs. A wide range of As concentration along the Campania coastline and Ni occurrence in the southern part of the region, mainly attributable to geogenic origin, was also evidenced. This approach allows extracting new knowledge from large dataset systematically collected by ARPAC monitoring activity, to support possible actions of contamination control and mitigation.

Coastal lagoons are important but sensitive environments, being transitional zones between land and sea. The Khnifiss lagoon is the most important desert wetland in Morocco, but little data have been produced concerning heavy metal geochemistry and enrichments in the sediments. Therefore, 26 surface sediments (15 intertidal and 11 subtidal) and 2 sediment cores were collected in 2016 and analyzed for a selection of heavy metals. The data were processed to assess the degree of contamination and the corresponding potential ecological risk, using several accumulation/enrichment indices, and the singular and multi-metal risk indices. Mean concentrations in the bottom layers of the two cores, dating from a pre-industrial age according to geochronological analysis, were used as the local geochemical background. The resulting values were on the whole lower than those reported for other areas of the northeastern coast of Morocco. Multivariate statistics were also applied to better understand relationships among variables (metals and other geochemical parameters) and to reveal similarities among sample groups. The results showed that, although the lagoon is not yet affected by significant anthropogenic influences, small enrichments can be recognized, especially for Ni and Cd. The cause may be related to the proximity to the main national highway, the vehicles and machinery used in the saltworks located in the area, and the small harbors used principally for fishing. In addition, industrial emissions from the Atlantic coast of Morocco and adjacent countries can be reasonably attributed as additional contributors to the enrichments. In terms of potential ecological risk, Cd shows the greatest impact compared to the other metals investigated.

The area of Bagnoli (Gulf of Naples, central Tyrrhenian Sea) has been heavily exposed to pollution for over a century due to the presence of industrial sites along its coastline. The aim of this study is to analyze contaminant concentrations (i.e., heavy metals and hydrocarbons) in seabed sediments through a statistical multivariate approach. Multivariate methods permit us to describe the pollution dynamics affecting the area and distinguish between anthropogenic and natural pollution sources. Additionally, the association between contamination patterns and the wave climate characteristics of the gulf (i.e., wave period, direction, height, power, and energy) is investigated. The study confirms that the main contamination source in the Bagnoli bay is anthropogenic activities (i.e., former steel plant and sewage discharges) for the majority of investigated pollutants. It also provides evidence, however, for the potential co-existence of multiple anthropogenic and geogenic sources of arsenic and other metals that may be originating also from the water-rock interaction and submarine volcanic emissions in the Phlegraean area.

The purpose of this study is to investigate the current status of contamination due to the heavy metal and organic substances (PAHs, HC >12, organotin compounds, PCB, DDD, DDE, DDT) pollution of the sediments from the coastal area of the Bagnoli brownfield (Naples, Italy) and draw some hypotheses on the origin and trends of industrial and also geogenic contamination. Surface sediments and cores were collected and analysed. The results showed remarkable concentrations of heavy metals, PAHs, and other substances that are significantly higher than the national guideline values of sea sediment quality. Correlation analyses and spatial distribution analyses showed that generally the inorganic and organic pollutants have similar patterns, confirming the common origin from the industrial activity, but also that some of the studied metals have some natural contribution originated from the geologic setting of the area. The distribution of most of the heavy metals (especially Cd, Hg, Pb, Cu, Zn, partially Cr and Ni) and PAHs are similar, and the highest concentrations were recognised between and just off the piers, but a diffuse contamination is widespread up to the external areas of the site perimeter, rising concern on the diffusion of contaminants to the whole Gulf of Pozzuoli.

Chemical contamination of marine ecosystems represents a major concern for the detrimental consequences at different levels of biological organization. However, the impact of chronic contamination on the diversity and assemblage composition of benthic prokaryotes is still largely unknown, and this limits our understanding of the potential implications on ecosystem functioning. The Bagnoli-Coroglio bay (Gulf of Naples, Tyrrhenian Sea) is a typical example of coastal area heavily contaminated by metals and hydrocarbons, released for decades by industrial activities, which ceased at the beginning of nineties. In the present study we analyzed the abundance, diversity and assemblage composition of benthic prokaryotic assemblages at increasing distance from the historical source of contamination in relation to the heavy hydrocarbons (C > 12), polycyclic aromatic hydrocarbons (PAHs) and heavy metal concentrations in the sediments. Prokaryotic abundance in the sediments differed among sites, and was mostly driven by environmental factors rather than by contamination levels. Conversely, the richness of prokaryotic taxa was relatively high in all samples, was driven by contamination levels and decreased significantly with increasing contamination (15–38%). Moreover, our results indicate large variations in the composition of the benthic prokaryotic assemblages among sites, mostly explained by the different levels and types of chemical contaminants found in the sediments. Overall, our findings suggest that chemical contaminants, even after decades from the end of their release, can profoundly influence the richness and turnover diversity of the benthic prokaryotic assemblages, in turn promoting a high diversification of the benthic bacterial and archaeal assemblages by selecting those lineages more adapted to specific mixtures of different contaminants. Our results open new perspectives for understanding of the long-term effects of chemical contamination on the benthic prokaryotic assemblages and the ecological processes they mediate.

The effects of contaminants on marine organisms have been documented since decades, but the long-term responses and recovery rates of benthic communities to mixtures of contaminants, several years after the cessation of industrial activities, need to be further investigated. Bagnoli-Coroglio Bay (Gulf of Naples, Tyrrhenian Sea) is a typical example of historically contaminated coastal area due to industrial activities stopped at the beginning of nineties. In the present study we carried out a fine spatial scale analysis of the distribution of meiofaunal (and nematodes) assemblages along five bathymetric transects located at increasing distance from the historical source of contamination in relation with the polycyclic aromatic hydrocarbon and heavy metal concentrations present in the sediment. Meiofaunal abundance and biomass changed widely along transects but independent from the distance from the source of contamination. Even when the contamination levels were expected to induce significant detrimental biological consequences, meiofaunal abundance and biomass were similar to those reported in unpolluted benthic coastal areas worldwide. Conversely, biodiversity in terms of meiofaunal taxa richness was generally low (range: 5–8 taxa in 12 of the overall 15 stations investigated). This was explained by the lack of sensitive groups such as ostracods, gastrotrichs and tardigrades commonly encountered in benthic coastal ecosystems, thus reflecting an overall poor/moderate environmental quality of the investigated area. Nematode (structural and functional) diversity was also low, particularly at stations characterized by higher contamination levels. At the same time, nematode species composition did not change significantly among stations suggesting a widespread effect of contaminants able to reduce the variability (i.e., turnover diversity) within the assemblages of the whole study area. Overall, our results indicate that even decades after the cessation of contaminant emissions, benthic biodiversity was affected in terms of both meiofaunal taxa and nematode species. These findings strongly reinforce the call for reducing sources of chronic pollution in marine ecosystems and provide new insights for a better understanding of the ecological recovery of historically contaminated marine environments.

Microalgae are considered good bioindicators of marine environmental quality. Frequently, they are used to investigate the toxicity of sediment elutriates, but their sensitivity is disputed. This paper compared the sensitivity of Phaeodactylum tricornutum (diatom), Skeletonema costatum (diatom), and Dunaliella tertiolecta (green alga), analyzing 257 samples of elutriates (1:4 sediment: water ratio), considering growth inhibition (72 h) as the reference endpoint and sediment chemical (metals, metalloids and polyaromatic hydrocarbons) and grain size. Results of the toxicity tests showed that the microalgae sensitivity was not correlated. The integration of chemical data did not allow to discriminate toxicity effects but contributed to highlight that D. tertiolecta was the most sensitive microalgae (no cell wall) followed by P. tricornutum and S. costatum. Further analysis, including lines of evidence and weight of evidence approaches to calculate risk quotients of elutriate samples, confirmed these results.

The aim of the present work is to demonstrate the practical importance of a multidisciplinary approach and weighted criteria to synthesize and integrate different typologies of data (or lines of evidence, LOEs), including chemical levels in marine sediments, their bioavailability to specific indicator species, ecotoxicological effects measured through subcellular biomarkers and batteries of bioassays, and potential impacts of pollution on local benthic communities. The area of Bagnoli (Gulf of Naples, Southern Italy) was selected as a model case-study, as it is a coastal area chronically impacted by massive industrial contamination (trace metals and hydrocarbons), and dismissed decades ago without any subsequent remediation or habitat restoration. The results of each LOE were elaborated to provide specific hazard indices before their overall integration in a weight of evidence (WOE) evaluation. Levels of some trace metals and PAHs revealed a severe contamination in the entire study area. Bioavailability of hydrocarbons was evident particularly for high molecular weight PAHs, which also caused significant variations of cellular biomarkers, such as cytochrome P450 metabolization in fish, lysosomal membrane destabilization in mussels, genotoxic effects both in fish and molluscs. The results of a battery of bioassays indicated less marked responses compared to those obtained from chemical and biomarkers analyses, with acute toxicity still present in sediments close to the source of contamination. The analysis of benthic assemblages showed limited evidence of impact in the whole area, indicating a good functioning of local ecosystems at chronic contamination. Overall, the results of this study confirm the need of combining chemical and biological data, the quantitative characterization of various typologies of hazard and the importance of assessing an integrated environmental WOE risk, to orientate specific and scientifically-supported management options in industrialized areas.

Fine airborne particulate matter (PM2.5) has been repeatedly associated with adverse health effects in humans. The PM2.5 soluble fraction, and soluble metals in particular, are thought to cause lung damage. Literature data, however, are not consistent and the role of leachable metals is still under debate. In this study, Winter and Summer urban PM2.5 aqueous extracts, obtained by using a bio-compatible solution and different contact times at 37 °C, were used to investigate cytotoxic effects of PM2.5 in cultured lung epithelial cells (A549) and the role played by the leachable metals Cu, Fe, Zn, Ni, Pb and Cd. Cell viability and migration, as well as intracellular glutathione, extracellular cysteine, cysteinylglycine and homocysteine concentrations, were evaluated in cells challenged with both PM2.5 extracts before and after ultrafiltration and artificial metal ion solutions mimicking the metal composition of the genuine extracts. The thiol oxidative potential was also evaluated by an abiotic test. Results demonstrate that PM2.5 bioactive components were released within minutes of PM2.5 interaction with the leaching solution. Among these are i) low MW (

Origin, yield and quality of the groundwater flows at high elevation in the Cimino volcano (central Italy) were examined. In this area, groundwater is geogenically contaminated by arsenic and fluoride, yet supplies drinking water for approximately 170,000 inhabitants. The origin of the high-elevation groundwater flows is strictly related to vertical and horizontal variability of the rock types (lava flows, lava domes and ignimbrite) in an area of limited size. In some cases, groundwater circuits are related to perched aquifers above noncontinuous aquitards; in other cases, they are due to flows in the highly fractured dome carapace, limited at the bottom by a low-permeability dome core. The high-elevation groundwater outflow represents about 30% of the total recharge of Cimino’s hydrogeological system, which has been estimated at 9.8 L/s/km2. Bicarbonate alkaline-earth, cold, neutral waters with low salinity, and notably with low arsenic and fluoride content, distinguish the high-elevation groundwaters from those of the basal aquifer. Given the quantity and quality of these resources, approaches in the capture and management of groundwater in this hydrogeological environment should be reconsidered. Appropriate tapping methods such as horizontal drains, could more efficiently capture the high-elevation groundwater resources, as opposed to the waters currently pumped from the basal aquifer which often require dearsenification treatments.

Nine cross-cutting issues which could foster or impede food and nutrition security are discussed. These are the concept of the right to food; gendering food security; land tenure; population growth pressure on land and water resources; empowerment and resilience through access to factors of production; food security governance; government capacity to formulate, implement, and institutionalize change and reform; food sovereignty; and climate change.

A devastating rainfall in Tuscany in November 2012 provided the opportunity to study the diffusion of As and Sb along the Tafone mining area, under extreme conditions, by comparing their concentrations in water, soil, and river sediments in drought (equilibrium) periods against those observed immediately after a flooding event and after a period of 6 weeks rebalancing of the watercourse. The data obtained at equilibrium show a significant “natural” As and Sb contamination with the highest levels along the valley in the mine surroundings. Very high Sb and As concentrations in the sediment of the Tafone Lake cause a potential continuous supply of toxic elements to the river downstream. In surface waters (river water and lake), As concentrations exceed slightly, and only occasionally, the Italian regulatory limits, while, those for Sb are always widely exceeded. In addition, the soils collected along the Tafone valley show high Sb and As total content, and were studied by a novel nine-step sequential extraction protocol, proposed for assessing the bioavailability of As and Sb in sulphide ore mining-impacted soils. Experimental data show that As and Sb mobility is strongly affected by even small variations of the pH and redox conditions, thus controlling their release into the environment. The results obtained after the flood demonstrated that extreme weather events can induce two main problems: (1) the temporary increase of As and Sb amount transported by the river water to the sea, principally as particulate and colloidal material, and (2) the sediment transport out the mining area, reaching soils eventually used for agriculture, and the potential diffusion through the food chain.

Stream networks are highly complex systems, in which spatially complicated and temporally varying water quality patterns develop. River eutrophication is underlain by nutrient inputs across the entire stream network and is controlled by many interacting factors in an ever moving and renewing medium. These complex features must be perceived as a whole entity to control river eutrophication. The Szamos River is one of the largest tributaries of the Tisza River in Eastern Europe. It delivers high loads of nutrients and algal biomass and fundamentally influences the hydro-morphological, chemical and ecological status of the Tisza River. To improve the ecological status of the recipient river, nutrient and phytoplankton inputs from the tributary should be controlled, yet the two rivers belong to different countries, which are reluctant to harmonize management plans. This study aims at modeling trophic status of the tributary with the PhosFate nutrient emission model to outline a set of management measures that would satisfy both countries. Four management alternatives are analysed with altered landuse patterns, and management options. Each of these alternatives is evaluated against the present conditions.

This study concerns the occurrence of arsenic in the groundwater system of the Cimino-Vico volcanic area (central Italy), different parts of which are currently widely used for local drinking water supply and for irrigation. The system shows a complex groundwater circulation, including a continuous basal aquifer, discontinuous perched aquifers, groundwater flows at high altitude, and local interactions with rising thermal fluids. Data on arsenic contents in 250 water samples from springs and wells and in 68 samples from rock outcrops were measured and combined with already existing information. Results highlight that arsenic concentrations of groundwater are influenced by type of aquifer, groundwater flow path, arsenic content of the aquifer rocks, and interaction with fluids rising from depth. Waters circulating in the Vico volcanics, one of the prominent rock units of the area, have high concentrations of arsenic, both for the basal and the perched aquifers. A large fraction of the waters associated with this rock unit have arsenic contents higher than 10 μg/L (82 percent for basal, 40 percent for perched). In contrast, waters circulating in the Cimino volcanics have lower arsenic contents: 30 percent of the basal and 10 percent of the perched aquifers have arsenic concentrations greater than 10 μg/L. Through an integrated approach, including leaching tests to investigate the arsenic behavior concerning the water-rock interaction and a geostatistical modeling of data, it has been possible to identify and tentatively quantify suitable water resources that have arsenic content not exceeding the quality standards for human consumption.

Fine airborne particulate matter (PM

The increasing demand for environmental pollution control results in the development and use of new procedures for the determination of dangerous chemicals. Simple screening methods, which can be used directly in the field for a preliminary assessment of soil contamination, seem to be extremely advantageous. In our laboratory, we developed and optimized a rapid test for a preliminary evaluation of both the concentration and the mobility of some potentially toxic metals in soils. This screening test consists of a single extraction of the soil sample with a buffer solution, followed by the titration of the extracted solution with dithizone to determine the contents of bi-valent heavy metals (such as Pb, Cu, Zn, and Cd). This screening method was then directly applied in the field during the sampling campaign in the framework of an Italian–Serbian collaborative project, finalized in the study of metal availability in soils. The results obtained in the field with the rapid test were compared with those obtained in the laboratory following the conventional procedure commonly used to evaluate metal bioavailability (diethylenetriaminepentaacetic extraction). Moreover, selected samples were analyzed sequentially in the laboratory using the standardized BCR three-step sequential extraction procedure. The screening test gave results conceptually in good agreement with those obtained via the BCR procedure. These preliminary data show that the proposed screening test is a reliable method for the preliminary rapid evaluation of metal total concentrations and of potential metal mobility in soils, supporting sampling activities directly in the field. © 2017, Springer International Publishing AG.

To clarify the relationship between airborne particulate exposure and negative impacts on human health, focusing on the heavy metal content alone might not be sufficient. To address this issue, in the present work, mineral allocation and leaching behavior of heavy metals in the PM2.5 were investigated. This work, therefore, provides a novel perspective in the field of urban airborne particle investigation that is not currently found in the literature. Four sampling campaigns were performed in the urban area of Rome (Central Italy) during the winter and summer seasons (February and July 2013 and 2014, respectively). The measured concentrations of the regulated elements of As, Cd, Ni and Pb were consistent with those reported by the local Environmental Agency (ARPA Lazio), but non-regulated heavy metals, including Fe, Cu, Cr and Zn, were also found in PM2.5 and analyzed in detail. As a novelty, heavy metals were associated with the host-identified mineral phases, primarily oxides and alloys, and to a lesser extent, other minerals, such as sulfates, carbonates and silicates. Leaching tests of the collected samples were conducted in a buffered solution mimicking the bodily physiological environment. Despite the highest concentration of heavy metals found during the winter sampling period, all of the elements showed a leaching trend leading to major mobility during the summer period. To explain this result, an interesting comparative analysis between the leaching test behavior and innovative mineral allocation was conducted. Both the heavy metal content and mineral allocation in PM2.5 might contribute to the bioavailability of toxic elements in the pulmonary environment. Hence, for regulatory purposes, the non-linear dependency of heavy metal bioavailability on the total metal content should be taken into account. © 2017 Elsevier Ltd

Based on both chemical leaching and adsorption tests and a simple modelling using PHREEQC, geochemical behaviours of uranium during the ignimbrite–water interaction were evaluated mainly as a function of temperature, pH, and solution chemistry (esp., alkalinity). The main results of this work are: (1) uranium is more easily mobilized by slightly basic solution (pH 7.5) than by acidified water (pH 4.5) when relative concentrations of the main uranyl ion–calcium–carbonate species, Ca2UO2(CO3)3, increase from 0.6 to 90%; (2) the greatest leaching of uranium occurs at 50 °C (not at higher temperature) because the first dissociation constant of H2CO3 is directly correlated with temperature up to about 50 °C, but decreases from 50 to 80 °C. This directly influences the concentration of HCO3 − which is mirrored by dissolved CO2 variations; (3) the presence of alkalinity, total C-species and calcium controls the saturation index of sorbate solution with respect to calcite, influencing also speciation, solubility, and sorption of dissolved U; and (4) higher adsorption of uranium is obtained in tests with deionized water (90.0 ± 0.7 mg/kg, at equilibrium) compared to those performed with the natural water (26.0 ± 1.5 mg/kg, at equilibrium), strengthening the role of complexes between uranyl, HCO3 −, and Ca2+ ions in solution to explain the corresponding decrease in uranium adsorption.

A brief review on the occurrence of high natural concentrations of potentially toxic elements (PHEs) in soils and water is presented, analysing also various approaches and strategies applied in different Countries to address the problem of “natural” contamination. Starting from the well known case of arsenic, the situation for other elements such as beryllium, uranium and nickel, among the most interesting, is analysed. The analysis is based on already evidenced geochemical anomalies and on the possible evolution both in the estimate of their toxicological effects and the redefinition (lowering) of the limits at the moment imposed by legislation or suggested by guidelines. New data obtained in the ENEA laboratory in the last years on arsenic and beryllium are presented. The growing need of “geochemical maps” at regional, national and European level and of a continuous monitoring activity is highlighted. At the same time the importance of considering concentration and speciation of elements and how an element is bound and under what circumstances it may be bioavailable and able to damage the ecosystem, is recalled. Finally it is suggested to concentrate efforts on the development of screening methodologies that could play a key role in the characterisation of contamination and on standardising fast procedures that enable a guided real-time survey. The clear definition of a “geochemical risk” requires a complex and multidisciplinary approach, so the emerging role of Medical Geology is underlined. © 2015, Accademia Nazionale dei Lincei.

In view of the establishment of quality standards for uranium in drinking water by the European and Italian authorities, we report a comprehensive overview of the Italian situation regarding uranium concentrations in natural waters. More than 3100 data on waters all over Italy are reviewed in addition to new data for Latium Region (Central Italy) where relatively high concentrations in rocks are long been known. Our study evidences that uranium in bedrock is not the main factor ruling uranium presence in fresh and groundwater, indicating that redox conditions as well as bicarbonates and silicates control solution equilibria and accordingly the uranium content in waters. At present, and considering the provisional guideline value of 30 μg/L established by [WHO (2012) Guidelines for Drinking-Water Quality. World Health Organization, Geneva], no critical situation is envisaged in Italy, but this can be overruled if lower limits will be actually imposed. There is also a need of further studies on uranium speciation in water and of wider epidemiological studies to assess its real toxicity to overcome the uncertainties that have so far hampered the definition of reliable water quality standards. © 2015, Accademia Nazionale dei Lincei.

Soil loss evaluation by means of radioisotopic content measurements represents a promising technique, half-way between field surveys and theoretical models, which still suffers from its practical limits when applied at basin scale. A main limit is represented by the costs of field investigations and laboratory investigations on the high number of soil samples required by a traditional sampling scheme, such as regular grid or transects. A non-conventional soil sampling scheme was tested with the aim to consider a relative scanty number of soil samples and to verify the feasibility of this technique on large areas. This scheme was based on the hypothesis that land analysis and classification could point out areas characterised by homogeneous behaviour with respect to the 137Cs deposition and transmission model. A Geographic Information System (GIS)-aided procedure allowed to classify the selected basin area in pedo-morphological units, representative of the different pedologic, morphologic and land-use conditions, to locate few sampling points for each unit. Outcomes pointed out a low correlation between 137Cs contents and soil physical and compositional characteristics. Nevertheless, the isotopic methodology allowed to estimate a total soil loss value at basin scale almost consistent with both observed data, given by reservoir sedimentation measurements and estimates from the application of the RUSLE model. Thus, the results can be considered encouraging and they allow to deem that the isotopic methodology can be refined in order to account for erosion and deposition processes even at river basin scale and with a limited number of soil samples.

Geochemical background concentrations of potentially harmful elements and species (PHES) may have a high spatial variability and their natural levels can be higher than those caused by anthropogenic sources of pollution. Therefore, the use of a threshold value for assessing contamination can be inadequate and local variability should be considered. In Europe, soil quality standards are widely variable. In Italy concentration levels exceeding threshold values (TVs) are allowed only if the natural concentrations for a given area are higher than those specified by law. For sediments, in Italian law TVs have not been yet established but TVs with local validity are used for contamination assessment in areas with different geochemistry. A short outline of the worldwide regulatory frameworks is presented with the intent of singling out suitable approaches and priority actions needed to tackle the weak points in law, following the indications of the scientific community and stressing the importance of assessing the real hazard using tools for the evaluation of site-specific mobility and toxicity of PHES. Cases of areas with high PHES background concentration are presented as evidence of this widespread phenomenon and of the need to find effective approaches and solutions.

Purpose: The assessment of risk related to the presence of potentially toxic elements in soils is strictly related to the knowledge of their form and mobility. These relevant properties depend on the complex interactions of the elements of concern with the soil particles that generally cannot be addressed by a single technique. This study presents an integrated approach implementing geochemical and mineralogical investigation techniques on samples from a former mining area (Tolfa Mountains district, northern Latium, Italy), where exploiting activities occurred until the recent past. In particular, the As total concentration and the As distribution in solid phases is studied with the aim to evaluate the possibility of environmental pollution and consequent risks for the health of people living in the area and possibly affected in case of significant mobilization of this toxic element. Materials and methods: Chemical (ICP-MS, ICP-OES) and mineralogical (Xray diffraction (XRD), scanning electron microscopy–energy dispersive X-ray (SEM-EDX), X-ray absorption near-edge structure (XANES)) analyses and the evaluation of the heavy metal mobility (by means of a sequential extraction procedure) were performed. Results and discussion: Chemical analyses show a high As content in the soils collected immediately downstream the marcasite mine waste deposit, that is the starting point of As pollution over the whole area. XANES analyses show that As occurs in two oxidation states (AsIII and AsV) simultaneously in the tailing samples and nearby, while it has been mainly or totally transformed into AsV at increasing distance from the mine. XRD data show that sheet silicates don’t affect As behavior, whereas sequential extractions and SEM-EDX analyses reveal the evident association of As and Fe oxyhydroxides content. Conclusions: The use of an integrated geochemical-mineralogical approach allows to single out the contaminant forms and the relative potential threat. Arsenic in the surface level of such soils could be mobilized in the case of extreme meteorological or of a not well planned human event, even though there is no evidence yet of any serious contamination of either underground or flowing waters.

Beryllium is widely distributed in soils at low levels, but it can also occur naturally in higher concentrations in a variety of materials exploited for many industrial applications. Beryllium is also one of the most toxic natural elements and is known to be a human carcinogen. A concise account of the literature data on baseline concentrations of Be in soils illustrates the possibility of worldwide presence of areas with a high natural background concentration of Be (up to 300 mg/kg), the crustal abundance of which is generally estimated to be in the range 2-6 mg/kg. Nethertheless the number of available data is rather limited in comparison with those about other toxic elements such as Pb, Cd, Cr…This could have probabibly caused the choice of low values of concentration level as the reference ones for the definition of soil as contaminated: these values are not always realistic and applicable to large areas.As a case study we report and analyse a diffuse, unusually high (up to 80 mg/kg, average approximately 20 mg/kg), natural occurrence of beryllium in loose and poorly consolidated pyroclastic layers related to the Pleistocene activity of the Vico volcano. Additionally, the analysis of Be leachability has been carried out, providing evidence of a not negligible mobility in contrast with the scarce data presented in the literature that usually indicate beryllium as an element with low mobility in slighty acidic and oxidising surface environmental conditions. This research is proposed as a starting point for a possible possible reappraisal of beryllium geochemical behaviour and background levels, providing more realistic and flexible reference values for risk assessment and land management.

Nanomaterials are revolutionizing the field of medicine to improve the quality of life due to the myriad of applications stemming from their unique properties,including the antimicrobial activity against pathogens. In this study,the antimicrobial and antibiofilm properties of a novel nanomaterial composed by zinc oxide nanorods-decorated graphene nanoplatelets (ZNGs) are investigated. ZNGs were produced by hydrothermal method and characterized through field-emission scanning electron microscopy (FE-SEM),energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) techniques. The antimicrobial activity of ZNGs was evaluated against Streptococcus mutans,the main bacteriological agent in the etiology of dental caries. Cell viability assay demonstrated that ZNGs exerted a strikingly high killing effect on S. mutans cells in a dose-dependent manner. Moreover,FE-SEM analysis revealed relevant mechanical damages exerted by ZNGs at the cell surface of this dental pathogen rather than reactive oxygen species (ROS) generation. In addition,inductively coupled plasma mass spectrometry (ICP-MS) measurements showed negligible zinc dissolution,demonstrating that zinc ion release in the suspension is not associated with the high cellmortality rate. Finally,our data indicated that also S. mutans biofilm formation was affected by thepresence of graphene-zinc oxide (ZnO) based material,as witnessed by the safranin staining andgrowth curve analysis. Therefore,ZNGs can be a remarkable nanobactericide against one of the maindental pathogens. The potential applications in dental care and therapy are very promising. © 2016 by the authors; licensee MDPI,Basel,Switzerland.

Mineralogical and geochemical studies were undertaken in the volcanic area of Biancavilla (Catania, Italy) with the aim of explaining the nature of the high As and F contents of the area’s rocks. As and F contents in soils and groundwater were also investigated. The metasomatised benmoreite lavas show fluorine and arsenic concentrations up to about 3,000 and 1,000 mg/kg, respectively. Mineralogical analyses show that fluorine occurs mostly in fluoro-edenite and apatite-(CaF) crystals, both abundantly present in the altered rocks, while As is exclusively attributed to the apatite-(CaF) crystals. Specifically, arsenic was observed only at the borders of these apatite crystals. Leaching tests and sequential extraction procedures were carried out to evaluate the potential remobilisation of As and F by the mineral phases and the eventual risks induced by their spreading. The results of the leaching tests suggest that As is almost totally associated with the ‘easily reducible’ fraction and that it is released by the preferential dissolution of the arsenic enriched rims of apatite-(CaF) crystals. In soils, As concentration is relatively low (about 15 mg/kg, on average), while F ranges from 236 to 683 mg/kg. The underground waters supplying the town of Biancavilla show As and F contents lower than the allowed limits for drinking water, (As:10 μg/L, F:1–1.5 mg/L). The limited distribution of these rocks and the relatively limited mobilisation by the minerals both contribute to maintain low As and F values, in soils and groundwaters, despite the high values in metasomatised lava samples.