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This work is aimed to assess potential risk associated with the presence of metals and metalloids in soil at "Playa Las Petroleras" sector, located in Antofagasta (Chile). The zone under study has been affected by four oil spill events. This sector is located in an urban area by the sea. So, it has a great social and environmental relevance. The concentrations of 15 elements in soil samples were assessed, four of them presenting potential ecological risk: As, Co, Cu, and Pb. Nine pollution indices were applied to data: four single pollution indices and five integrated pollution indices to assess soil pollution. The single pollution indices show that the site bears potential ecological and environmental risk due to the presence of Cu, the site being classified as highly contaminated owing to a severe enrichment of this metal. For Co, all the indices allow classifying the site as little or uncontaminated, while the level of As and Pb pollution could be considered as ranging from uncontaminated to moderately contaminated. The integrated pollution indices show that average concentrations are highly contaminated mainly owing to the presence of Cu.

Circular economy is based on the re-use of wastes. However, it also implies the application of solutions that can help to reduce the environmental and climate change impacts. On the one hand, the preparation of materials for construction from mining activities generates wastes, for instance in marble and stone industry. On the other hand, the use of these materials in construction also generates wastes, construction and demolition wastes (CDW), which account for more than a third of all waste generated in the EU. In the case of the SE of Spain, stone preparation (cutting, polishing, etc…) produces fine and coarse wastes, mainly from carbonate rocks and secondary from granites. The large building activity produces residues in a wide variety of materials (concrete, bricks, wood, glass, metals and plastics). Mining restoration could be an opportunity to reuse those materials, as many mining holes are abandoned and need to be refilled before the preparation of a soil cover and landscape recovery.In this work, it has been studied the restoration of an ancient mining hole (up to 10 meters depth and 21000 m2), situated in the SE of Spain under a BSk climate -Köppen and Geiger classification-, with marble wastes and CDW, and finally the formation of a Technosol (IUSS Working Group WRB) which can support a vegetation cover. Several actions were done as follow: refilling of the mining hole first with marble wastes (calcareous materials mainly of different sizes), the second was the addition of CDW and the third was the mixing of CDW with topsoil (approximately last 50 cm depth of surface restoration) forming the surface and conditioning the topography to reduce soil erosion. This action was accompanied by the construction of a central drainage stone filled canal (50 cm depth). After two years, Pinus halepensis vegetation was introduced (261 pine trees). Two years later, soil samples were taken (0-5 cm to measure bulk density and 0-20 cm depth to measure pH, electrical conductivity and organic matter) in eight selected points distributed equidistant in the restored area. The results showed that the soil had a slightly basic pH, but not homogeneous along the surface (from 8.13 to 8.89). In the case of the electrical conductivity, the variation between samples was greater (0.49 to 2.41 dS/m) and probably controlled by the lithology of the area, in the north close to Triassic formations with soluble gypsum formations and in the middle to the south to calcareous rocks. The organic matter (between 1.13 to 1.59 %) and the bulk density (1.40 to 1.47 g/cm3) were more homogeneous in the restored area. The survival of the pine trees was successful and more than 80%, considering no irrigation applied excepting the first month.The use of this materials could be of interest to reduce the impact, favoured the circular economy and restoration of ancient mining areas, recovering the landscape and the soil functions.

The Central Federal District (CFD) of Russia is a highly populated area with a developed infrastructure where agriculture specializes in the cultivation of cereals, vegetables, sunflowers, and cattle breeding. The territory is also known for a deficiency of Cu, Co and I in the environment and respectively in the main agricultural plants and animals cultivated in the CFD, as well as in the diets of the local rural and urban population living on local products.The cartographic basis used for the creation of preliminary assessment maps of the distribution of trace elements in the soil cover of the region was the Unified State Register of Soil Resources of Russia (scale 1:2 500 000). Levels of Cu, Co and I content in soils were based on our original experimental database and published data of the elements concentration in the cartographic units "topsoil-subsoil". To estimate the ecological and geochemical risk we used threshold concentrations in soils leading to specific diseases in cattle grazing within the particular areas. These concentrations were based on numerous experimental data obtained by different scientific teams (Kovalsky, 1974, 1991; Korobova, 1992; Ermakov, 2015, etc.).The mapping allowed demonstration of zonal and regional peculiarities in Cu, Co and I status of the soil cover in CFD. The obtained cartographic estimates are comparable with the published averaged results at the oblast level. Comparison with the published medical information on the cases of thyroid disease registered for the first time in their life for the period from 2013 to 2017 on the level of administrative unit "oblast" showed a significant (p=0.08) inverse (R=-0.47) correlation with our cartographic estimates of soil iodine status weighted for the corresponding oblast's with due regards to their soil structure (numbering 14 in CFD with exception of Bryansk and Oryol oblast'). The two indicated oblast's were considerably affected by radioiodine shock during the Chernobyl accident which contributed to increase of thyroid damage especially in case of its suffering from iodine deficiency.

Attic dusts provide an indirect measure of airborne pollutants deposited in the urban environment. The objectives of this study are: (1) to determine the concentrations of As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V and Zn in attic dust in the City of Coronel, (2) to evaluate the source apportionment of PHE and (3) to assess the risk of health effects from exposure in adults and children. In the City of Coronel, attic dust samples were collected in 19 houses. The concentrations of As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V and Zn were measured in ICP-OES after Aqua Regia digestion of 75 µm dust sample. The median (and the range) concentration (mg kg

Многолетние исследования Северо-Кавказской геохимической провинции позволили установить местные кларки и кларки концентрации (рассеяния) химических элементов в горных породах, почвах и растениях. Рассматриваемую провинцию характеризует ряд региональных особенностей. Ассоциации элементов, находящихся в повышенных и пониженных концентрациях, часто определяются преобладающим составом горных пород (карбонатно-терригенные, терригенные, магматические). Изучение средних содержаний ряда химических элементов в почвах провинции показало, что в ассоциацию аккумулированных элементов входят металлы с различными миграционными особенностями. Так, несмотря на довольно близкие размеры ионных радиусов, для Pb, Zn, Cu, Li (судя по ионному потенциалу) характерно образование катионов, а Mn, Mo, Zr образуют сложные комплексные ионы. На сероводородных барьерах, в основном, осаждаются Zn, Cu, Pb, а Mo, Co, Mn – на кислородных. Для Cu, Zn, Mo, Co биогенное накопление играет существенную роль, а для Pb, Ni оно практически отсутствует. Величины абсолютного разброса элементов не достигли экологически опасных значений, но свидетельствуют о довольно интенсивной миграции. В древесных растениях наиболее интенсивно накапливаются Ba, Nb, Sc, Sr, Zn. Специфические природные условия, характеризующие Северо-Кавказскую геохимическую провинцию, должны оказывать влияние на развитие техногенеза и его последствия.

The highly rugged mountainous land topography of the Novorossiysk industrial agglomeration (NW Caucasus, Krasnodar Krai, Russia) and arid climate limit the restoration abilities of disturbed mine lands. Abandoned waste-rock dumps of a marl quarry occupy an area of ca. 150,000 m2 next to the cement plant, residential districts, and a commercial seaport. To assess the eco-risk, topsoil horizons of urban and mine-site Technosols and background Rendzinas were sampled and analyzed; measurements of particulate matter fractions PM1, PM2.5, PM4, and PM10 were conducted throughout the agglomeration. Fugitive dust emission from the unreclaimed marl dumps raises the PM2.5 content in the air by a factor of 2.68 on average. The high sorption capacity of the fine eluvium results in the accumulation of urban emissions by the dust and contributes to the subsequent soil pollution; the Cumulative Pollution Index of pedochemical anomalies reaches the high-risk level over the areas of up to 5 km2. Environmental threats caused by the mine dumps can be assessed more reliably by means of land zoning based on accumulated environmental damage indicators and the debris flow and waterspout risk calculation. To abate the technogenic impact caused by the mine spoils, reclamation actions must be taken including soil stabilization on sensitive sites by application of geosynthetic cover, hydroseeding of the mixture of soil improvers and seeds of herbaceous plants on the slopes, and anti-erosion plantation of cades (Juniperus oxycedrus L.) and smoke trees (Cotinus coggygria Scop.) at subhorizontal surfaces.

The study is aimed at identifying patterns in distribution of pollutants in the elementary landscape-geochemical systems (ELGS) of the temperate zone. The study used 137Cs as a tracer, which allows a highly detailed analysis of the nature of the heterogeneity of secondary migration in the toposequence: summit—slope—closing depression, treated as the elementary landscape-geochemical system. The study site was located in the Bryansk region in the Chernobyl abandoned area with an initial level of 137Cs contamination exceeding 1480 kBq/m2 (40 Ci/km2). An original technique of repeated 137Cs measurements along cross-sections accompanied by topographic survey and soil cores sampling has been applied. The obtained results showed a complete absence of constant increase of 137Cs concentration downslope but revealed a steady regular variability of 137Cs activity of a cyclical type. Given uniformity of the initial 137Cs fallout within a small-sized plot, variation of 137Cs due to its secondary distribution in ELGS was 2–2.7-fold according to field gamma-spectrometry data which corresponded to the radionuclide contamination density of the top 20-cm layer of the soil containing 96–99% of the total radionuclide amount (correlation between the parameters equaled to r0.01 = 0.782, n = 20). A specifically regular structure obviously formed under the set of radionuclide water migration processes seems to be inherent in all systems of the studied type. The results obtained are believed to be of both theoretical and practical importance, since they can contribute to making decisions on the precise monitoring of zones of technogenic accumulation, as well as solving fundamental problems of soil formation and its restoration after technogenic pollution.

The precipitation of sparingly soluble calcium phosphate in calcareous soils decreases the bioavailability of macronutrients, which makes their addition by way of fertilisers necessary. Sludge resulting from treating urban wastewater does not only provide significant amounts of phosphorus, but also helps lower the pH, thus increasing its bioavailability. The loss of part of soil nutrients due to irrigation or rain can contaminate groundwater. In order to assess the movement of phosphorus, a experiment was conducted on percolation columns, to which different doses of wastes were applied. The pH decreased by as much as 0.89 units, as well as the assimilable and soluble P, in intervals of 20 cm of depth, obtaining maximum values of 254 mg P kg−1 and 1455 μg P kg−1 respectively, and the P present in the leached water collected, which did not surpass 95 μg PL−1. The intent was to learn which was the majoritarian inorganic formed crystalline phase that immobilised the movement of phosphorus through the percolation column. The results obtained by the diffraction of X-rays are not conclusive, although they point to the formation of octacalcium phosphate. The diffractograms of the studied samples have similar diffraction lines to those of apatites.

Accumulations of potentially toxic metals were investigated in soils and five North Caucasian Alyssum species from metalliferous areas and non-metalliferous areas in Karachay-Cherkessia, Kabardino-Balkaria, Dagestan and the Krasnodar region. Analyses of field samples showed that chemical features of the soils significantly affected the concentrations of Ni, Co, Zn, but had less effect on Cu and Pb concentrations in the shoots of Alyssum. Variations in the degree of accumulating ability were found in the studied species, including hyperaccumulation of Ni in Alyssum murale (up to 12,100 mg kg−1), and significant accumulation of Zn in A. gehamense (up to 1700 mg kg−1). A comparative molecular genetic analysis of two A. murale populations, both Ni-hyperaccumulating population from Karachay-Cherkessia and non-hyperaccumulating population from Dagestan, indicated considerable genetic difference between them. This result supports the hypothesis that the selection of metal hyperaccumulator species with enhanced phytoremediation efficiency should be considered at the population level.

Soils and plants of Saint Petersburg are under the constant technogenic stress caused by human activity in industrial, residential, and recreational landscapes of the city. To assess the transformed landscapes of various functional zones, we studied utility, housing, and park districts with a total area of over 7,000 hectares in the southern part of the city during the summer seasons of 2016-2018. Throughout the fieldwork period, 796 individual pairs of soil and plant samples were collected.A complex of consequent laboratory studies performed in an accredited laboratory allowed the characterization of key biogeochemical patterns of urban regolith specimens and herbage samples of various grasses. Chemical analyses provided information on the concentrations of polluting metals in soils and plants of different land use zones.Data interpretation and calculation of element accumulation factors revealed areas with the most unfavorable environmental conditions. We believe that a high pollution level in southern city districts has led to a significant degree of physical, chemical, and biological degradation of the soil and vegetation cover. As of today, approximately 10 % of the Technosols in the study area have completely lost the ability to biological self-revitalization, which results in ecosystem malfunction and the urgent need for land remediation.

The use of indicators for soil monitoring is a long-established methodology that can be applied in the context of climate change. It makes it possible to establish the state of the variable to be measured and to obtain an objective signal of the changes that occur over time. Obtaining a climate adaptation indicator (CAI) for Mediterranean rainfed soils is a very useful monitoring tool for decision-making and for the incorporation of mitigation measures.Within the LIFE AMDRYC4 project, a framework has been outlined in which a) environmental indicators of the chemical degradation of soils (salinity, alkalinity, fertility, phytotoxicity) and the erosion indicator, b) biodiversity indicators (vegetation indices, Shannon-Weaver indices, Simpson, ...) and c) organic carbon indicator have been used. These primary indicators can be summarized resulting in a higher rank one represented by the soil ecosystem services indicator (SESI) which reflects the soil global condition obtained from the base data for each established monitoring point. By combining the SESI with a transformative indicator such as the one calculated on the basis of the increase of organic C in the soil (mitigation indicator, MI), the indicator of climate adaptation is obtained, using a procedure based on fuzzy methodology.In the calculation of the phytotoxicity indicator, the assimilable values of selected trace elements that can cause phytotoxicity are determined and their variation over time is monitored. The selected trace elements, in this case Pb, Cd and B, may vary from one area to another depending on the geochemical background of the soil. The results obtained for several soil plots that have been subjected to organic matter incorporation treatments (sewage sludge, manure from different animals, composted plant remains) and their untreated counterparts (blank) clearly show an improvement of the soil characteristics after the application of the mentioned soil treatment strategies. The soils are not affected by the polluting processes, both in terms of potentially toxic elements and other emerging pollutants. The experimental data obtained indicate that the remediated soils can be useful to reduce the concentration of greenhouse gases in the atmosphere and represent a good tool for combating climate change.The authors are grateful to LIFE16 CCA/ES/000123-LIFE AMDRYC4 Project for the financial support

The extraction of solid fossil fuels results in the accumulation of overburden and host rocks stored on the Earth's surface. Coal mining sites are among the most disturbed and polluted areas. Soils are affected by these transformations in multiple ways, including structural changes, the loss or suppression of vegetation cover, and the migration and accumulation of chemical elements in soils and water. To assess the global concentrations of chemical elements in the coal mine soils, we discussed and developed a meta-study on pollutants in Technosols and altered natural soils. For this, we collected data from papers published in peer-reviewed journals between 2000 and 2022, covering 25 major coal-producing countries of Eurasia, Africa, Australia, and the Americas. To understand better the patterns of soil pollution driven by coal extraction itself, we gathered the concentrations measured in soils, spoils, and dumps near open-cut and underground coal mines. For the same reason, the data on pollutants in remediated or reclaimed soils, as well as in soils near coal power plants (or other pollution sources) were excluded. Likewise, we did not consider other abiotic (e.g., coal ash, mine water) or biotic media (e.g., grasses, trees, and plants in general) even though they are undoubtedly interlinked. Moreover, the data on soil pollution are far more abundant and thus statistically significant.The typical set of keywords used for searching in databases included “coal mine”, “soil/dumps”, “pollution/contamination”, and “elements/metals”. Obviously, other terms like “colliery”, or “wasterock”, or “geochemical transformation” were applied too but gave fewer search results. To harmonize measurement units, we recalculated all data to mg/kg or ppm. When necessary, concentrations were recalculated from oxides into elemental forms. To confirm the representativeness of the figures, we checked the number of specimens analyzed in each research. The total number of samples used in the meta-study was over 7,000. For the standard statistical processing, the mean concentrations were collected alongside the minimum and maximum contents, and standard deviation values; when not provided in a paper, they were calculated from the raw data. After that, we obtained the average contents of chemical elements that characterize each coalfield separately.The preliminary results reveal that priority pollutants are inherited from the world averages for trace element contents in coals rather than the natural background. In other words, concentrations of priority pollutants are predominantly determined by coal extraction and the release of related pollutants. The research outcomes indicate that the oxidation-reduction and alkaline-acid milieu, water and temperature regimes, sorption capacity, and other landscape-geochemical conditions are being ambiguously transformed in new ecosystems and can be derived from both natural conditions and the man-inflicted damage. The geochemical cycles in biocenoses are altered and the tasks for their restoration may vary significantly. The established global concentrations of chemical elements in coal mine soils can be used for comparative assessments and the management of legacy contamination and soil/landscape rehabilitation in post-mining regions. However, remediation efforts will also need to consider site-specific geological, hydrological, and climatic characteristics as well as socio-economic conditions and other regional development objectives.

Arsenic is a Potentially Toxic Element (PTE), which is present in the soils/sediments of abandoned mining areas, such as the Sierra Minera de Cartagena La-Unión and the mining site of Mazarron (SE Spain) and its areas of influence. In order to assess the risk to human health and the ecosystem, it is necessary to know the nature of the materials that contain this PTE, their alterability and their speciation.On the one hand, there is a geogenic relationship between this element and materials rich in phyllosilicates and Fe minerals. These minerals can constitute primary mineralisation such as sulphide veins (pyrite, arsenopyrite, etc.) or secondary mineralisation such as haematite, goethite, siderite, jarosite, etc., and can even be found as a mineral phase forming various arsenates. Another very important aspect is the climatology of the area, which coincides with a semi-arid Mediterranean climate with infrequent but very heavy rainfall.The As concentration range in the studied areas is very wide (5000 -70 mg.Kg-1), with an average value of 150 mg.Kg-1, being As (V) the predominant species. Only soils located in wetland areas with permanent waterlogging can show significant concentrations of As(III). The As content in surface waters, such as runoff water, is low, only reaching significant values (>2 mg.L-1) when these waters are acid mine drainage and have pH values Particulate As is associated both with Fe oxides and hydroxides, through surface adsorption processes on Fe(OH)3 particles, and with carbonates, through precipitation reactions as calcium arsenate. These reactions are evident in some places such as wadis that transport particulate and dissolved materials from areas affected by mining, and mainly take place both in the riverbed and in flooding areas when rainfall events occur.For an appropriate understanding of the main processes involved, a detailed scheme is given. It should be noted that the dynamics of this PTE is of a particular interest in the zones studied due to the proximity of urban sites.

Wastelands of the mining industry are among the largest of disturbed areas that demand revitalization. To reduce environmental impact and to better manage these geo-resources, the formation of sustainable plant and soil complexes and the restoration of self-recovery soil function are critical points. The successful return of vegetative cover at post-mining sites requires eliminating the deficiency of organic matter. For this, we assessed the usability of non-traditional ameliorants to provide a better understanding of benefits from mutual dependencies of environmental resources. To prevent losses and to close resource cycles, we studied the applicability of wastewater sludge from the pulp and paper (SPP) industry as an amendment to counteract soil degradation and rehabilitate human-disturbed lands. Waste rock limestone, beresite, and phosphogypsum substrates of post-mining sites were used in vitro for the application of sludge and peat mixture and consequent grass seeding. The formed vegetative cover was analyzed to compare the germination and biomass growth on reconstructed soils. We assessed the efficiency of ameliorant combinations by two approaches: (1) the traditional technique of cutting-off plant material to measure the obtained plant biomass, and (2) digital image analysis for RGB-processed photographs of the vegetative cover (r2 = 0.75–0.95). The effect of SPP on plant cover biomass and grass height showed similar results: land rehabilitation with the formation of a 20 cm soil layer on mine waste dumps was environmentally suitable with an SPP:soil ratio of 1:3. However, excessive application (ratio 1:1 of SPP to the soil) negatively affected seed germination and plant vegetation.

Very little information is available about Hg and Cr evolution in greenhouse soils. This paper presents the results of determining Hg and Cr in greenhouse soils in a semi-arid region in the southern Iberian Peninsula (Almeria, Spain), and assessing the enrichment level and the Potential Ecological Risk Index (PERI) according to crop age. Hakanson’s approach was used to evaluate the PERI. To investigate the behaviour of Hg and Cr in greenhouse soils over time, samples were grouped into values in soils for blocks according to crop age: 0 years, 5–10 years, 10–20 years, more than 20 years. The results showed that 74% of GS exceeded the obtained background level (37.1 μg kg−1) for Hg, with 43% (48.9 mg kg−1) for Cr. Temporal patterns indicated that these elements are accumulating in greenhouse soils and this trend was very significant for Hg. After more than 20 intensive crop-farming years, concentrations and the PERI had clearly increased. Although the ecological risk was moderate, our observations suggest that the farming practices performed in the last 35 years have allowed these metals to accumulate. In fact, the 15% of the studied soils presented a considerable potential risk and were the soils that had been used longer.

Urban soils are a key component of urban ecosystems as they support biodiversity, provide foundation for infrastructure and play an important role in maintaining the environmental quality, being both a sink and a source of pollutants that have an effect in human health. The objectives of this study were (1) to determine the concentrations background of As, Co, Cr, Cu, Ni, Pb, V and Zn in the urban soils of Hualpen (Chile); (2) to assess the level of contamination in the urban soil based on different pollution indices; (3) to identify natural or anthropogenic sources in order to determine a spatial pattern of the pollutants and (4) to assess the health risks of trace metals in surface soils of Hualpen. A total of 153 samples were collected from the study area as follows: 51 topsoil samples (TS) (0–10 cm), 51 subsoil samples (SS) (10–20 cm) and 51 deep soil samples (DS) (150 cm). Multivariate statistics combined with spatial analysis were implemented in order to distinguish the sources. Several simple and robust statistical methods were applied to datasets in order to explore their potential in the evaluation of a useful and robust background values. The degree of contamination along with pollution indices were also evaluated. The median soil pseudo total concentrations of the elements were as follows: As 3 mg kg−1, Co 15 mg kg−1, Cr 14 mg kg−1, Cu 25 mg kg−1, Ni 36 mg kg−1, Pb 5 mg kg−1, V 97 mg kg−1 and Zn 51 mg kg−1. Multivariate analysis suggests that Cr, Pb, V and Zn are contributed by external sources. The spatial distribution of these elements displays a spatial pattern extending along industrial environments and emission sources. While the other elements show a spatial pattern with a few anthropogenic hot spots dispersed across Hualpen, they were influenced by both anthropogenic and geogenic inputs. The estimate background values determined with the DS samples with median absolute deviation (MAD) method were for As 5 mg kg−1, Co 20 mg kg−1, Cr 18 mg kg−1, Cu 33 mg kg−1, Ni 45 mg kg−1, Pb 3 mg kg−1, V 108 mg kg−1 and Zn 48 mg kg−1. The ecological indices register a moderate to considerable contamination in some soil samples. It was noted that the soils of Hualpen pose no carcinogenic risk, neither by inhalation nor by ingestion.

Abandoned mining areas are a clear example of the failure of the different administrations to solve the environmental problems they pose, due to the lack of unified legislation and management and the activity of geological processes. It is therefore important to have a clear vision of the environmental problems that occur and the possible actions to solve them.The Sierra Minera (Cartagena, SE Spain) presents situations of risk of soil contamination that coincide with those areas with the highest content of soluble and/or bioavailable PTEs (potentially toxic elements) for the health of people and ecosystems, especially in those sites of concentration of polluting sources (flotation mud pools and heterogeneous dumps), with a very fine texture. These areas present numerous points with an urgent need for risk management due to the possible mobilization in different environmental conditions of arsenic and heavy metals, with a control of both soluble and particulate dispersion. Special interest presents arsenic mobilisation in an acidic environment together with reducing situations and the presence of organic matter (waterlogged marshes).The recovery technologies to be applied in the Sierra Minera require a great diversity of techniques, depending on the uses of the land. In the contamination foci it is necessary to carry out actions with containment, stabilisation and solidification technologies in situ. Phytoremediation techniques, given the high content of PTEs present, may not all be appropriate in the different situations. Phytoextraction should only be applied in areas with low concentrations of PTEs, and by plants that do not transfer to their aerial part, to avoid the risk of ingestion by animals. Phytostabilisation will be important in combined techniques, in order to ensure that contaminants are not transferred to the environment, and by non-accumulating plants in the aerial part. Wetlands can be a complementary solution to the projects developed at the heading of wadis, providing a double purpose, natural attenuation of contamination and lamination of turbulence and floods.A generic overview is given of the most important regeneration approaches from a geochemical point of view, without going into structural solutions, selecting those technologies that are most suitable to the environment in which they are located, trying to imitate natural attenuation processes and using eco-efficient and sustainable materials.

“Rambla”are temporary watercourses, which are characteristic of mediterranean and semi-arid climates, with low rainfall and sporadic torrential rain. A few times a year, when the rainfall exceeds 80 mm in less than an hour, they are capable of evacuating high flows of water mixed with particulate material of different granulometries to the sea.The Sierra Minera of Cartagena (Murcia, Spain) has two marine slopes, one of short distance and steep slope towards the Mediterranean Sea, and another of a greater extent that affects the Mar Menor, a specially protected saltwater lagoon.The processes that can take place in the course of the ramblas that begin in the Sierra Minera, when water is present, are those of transport of particulate and soluble material, processes of dissolution, hydrolysis, redox, complexation, carbonation and precipitation among others. When the rainy season ends and the Surface water disappears, the sediments that have been left in the riverbed are subject to other secondary processes that lead to the formation of very particular mineralogical species, efflorescence of hydrated sulphates, carbonates and oxydroxides. This is due to the pore water which can remain for a long period of time in the sediments of the rambla bed. Depending on the degree of influence of the current mining sediments in the rambla, the water it transports can have an acid pH (3.5-5.5), being qualified as acid mine drainage.The Rambla del Beal is one of the various watercourses that cross the Sierra and flow into the Mar Menor next to a wetland that is an Special Protection Area (SPA), which makes the study more interesting. Like other ramblas in the area, during different periods, it carried the waste from the mineral floatation plants to the sea, as if it were a natural pipe, so along its route there are abundant terraces formed by this waste. This is in addition to the materials dumped and the materials eroded from the ponds and dumps that are in its receiving basin.A selective sampling has been carried out along the riverbed to its mouth, analysing the content of potential toxic elements (PTEs), granulometry, general characteristics and mineralogy.The bioavailability and mobility of the different PTEs (As, Pb, Zn, Cd and Fe) and their relationship with the mineralogy have also been studied.The results show that only in the central part of the rambla can sediments not affected by primary pollution be found (they are secondary pollution), and that the Rambla del Beal itself can be considered a focus or primary source of pollution by PTEs.

The use of phytostabilizing plants in remediation projects of areas affected by mining activities is one of the valid strategies for recovering the ecosystem. It is often used to obtain biodiversity with the aim of restoring the environment, but the possible risk represented by the ingestion of the plants by the fauna and the consequent passage of As to the trophic chain is forgotten.The aim of this study is to evaluate the environmental risk posed by arsenic when revegetation occurs in an area with high levels of this element. To this end, the transfer of arsenic in different plant species that grow spontaneously in an abandoned mining area (Sierra Minera de Cartagena) is analysed, as well as the contribution of these plants to the intake of mammals in the area. In order to make a comparison with the risk analysis applied to human intake, the wild boar is selected since this mammal has a digestive physiology very similar to that of humans. For this purpose, a gastric solution is prepared according to the standard operating procedure (SOP) developed by the Solubility/ Bioavailability Research Consortium (SBRC). Two phases, namely, stomach (AsA) and intestinal (AsN), are considered.In this way, it is possible to discriminate between plant species with high, non-bioaccessible contents in the aerial part and plant species with the opposite.For this study, 21 plant species that grow naturally in the soils of the Sierra Minera and their corresponding rhizospheres were collected.The physical-chemical properties were obtained using the usual procedures. To determine the arsenic content, the soil samples and plant materials were digested in a microwave system and the arsenic concentration was determined using atomic fluorescence spectrometry with an automated continuous flow hydride generation system. Soils are classified into three groups: Low (group 1) (7-35 mg/kg), medium (group 2) (35-327 mg/kg) and high (group 3) (> 327 mg/kg), according to their As content. The descriptive statistical analysis of the population of plants studied shows that the range of As in the roots were from 0.31 to 150 mg/kg, while the concentrations in the leaves were lower (0.21 to 83.4 mg/kg). The possible risk of As entering the food chain through plant species is evaluated. The route of exposure considered is the oral ingestion, calculating the contribution of the plant to the daily dose based on the concentration of arsenic (total and bioaccessible) in the leaves of the analyzed plantsIn general, the bioaccessible fraction by intake is low, although it is higher in the areas most influenced by primary and secondary pollution sources. The availability of bioaccessible As in the leaves of the plants is highly influenced by the mineralogical composition of the soils on which it grows.

The study presents a complex characteristic of zircon from the Verkhneurmiysky intrusive series with Li-F granites. A wide range of morphological and chemical properties of zircon allowed us to obtain new information on the formation and alteration of zircon from biotite and zinnwaldite granitoids and to determine its features, which contribute to the correct definition of Li-F granites formed directly before the tin mineralization. The reviled trends of zircon morphology and composition evolution in the Verkhneurmiysky granites series are: the high-temperature morphotypes are followed by low-temperature ones with more complicated internal structure with secondary alteration zones, mineral inclusions, pores, and cracks, the increasing concentration of volatile (H2O, F), large ion lithophile (Cs, Sr), high field strength (Hf, Nb) and rare-earth elements with decreasing crystallization temperatures and the determining role of the fluid phase (predominantly, F) in the trace element accumulation. The composition of zircon cores in biotite and zinnwaldite granites is very similar. However, the zircon rims from zinnwaldite granites are much more enriched in trace elements compared to those from biotite granites. The first study of zircon from the Verkhneurmiysky granitoids provides new data on the formation and alteration conditions of granitoids, including zinnwaldite ones.

A study was carried out to evaluate the absorption of potentially toxic elements from mining Technosols by three types of vegetable plants (broccoli (Brassica oleracea var. italica), lettuce (Lactuca sativa) and onion (Allium cepa)), the different parts of which are intended for human and farm animal consumption (leaves, roots, edible parts). The preliminary results obtained highlight the importance of the design of the mining Technosols used for agricultural purposes, obtained from soils and sediments of mining origin and amended with residues of high calcium carbonate concentrations (limestone filler and construction and demolition wastes). The experiment was carried out in a greenhouse, and the total metal(loid)s concentration (As, Pb, Cd, Cu, Fe, Mn and Zn) of the soil, rhizosphere, aqueous leachates and plant samples was monitored, the translocation and bioconcentration factors (TF and BCF, respectively) being calculated. The characterization of the soils included a mobilization study in media simulating different environmental conditions that can affect these soils and predicting the differences in behavior of each Technosol. The results obtained showed that the levels of potentially toxic elements present in the cultivated species are within the range of values mentioned in the literature when they were cultivated in soils with calcareous amendments. However, when the plants were grown in contaminated soils, the potentially toxic elements levels varied greatly according to the species, being higher in onions than in lettuce. Experiments with the use of lime filler or construction and demolition wastes for soil remediation result in crops that, in principle, do not present health risks and are similar in development to those grown on non-contaminated soil.

An urban world population of 0.75 billion in 1950 and expected 6 billion in 2050 shows the tremendous potential growth of urban areas. The urban soil fulfills the role of the reactor for the physical, chemical and biological transformations of matter but also covers such functions as reduction of air pollution, regulation of climate elements in cities, source of biodiversity and formation of areas for ornamental and recreation purposes. As a usual part of urban ecosystems, urban soils in general have high concentrations of trace elements derive from human activities. The objectives of this work were (1) to quantify the concentrations and establish background levels of Ba, Co, Cr, Cu, Mn, Pb, Ni, V and Zn in soils of Coronel city; (2) to assess the degree of pollution and identify local sources of pollution and (3) to assess the health risks of TE in soils of Coronel city. From Coronel city were collected 129 samples from 43 sites located in schoolyards and playground areas. At each sampling point were taken three samples: topsoil sample (TS) (0-10 cm), subsoil sample (SS) (10-20 cm) and deep soil sample (DS) (150 cm). Multivariate statistical analysis and depth ratios were used to distinguish the source. Ecological indices were implemented to evaluate the degree of contamination. The median and (range) of the trace elements (TE) in TS were Ba 38 mg kg-1 (12-147 mg kg-1), 38 mg kg-1; Co 4-40 mg kg-1; 15 mg kg-1; Cr 10-35 mg kg-1, 18 mg kg-1; Cu 12-70 mg kg-1, 22 mg kg-1; Mn 167-950 mg kg-1, 536 mg kg-1; Ni 11-115 mg kg-1, 35.5 mg kg-1; Pb 1.5-115 mg kg-1, 6 mg kg-1; V 52-528 mg kg-1, 94 mg kg-1; Zn 42-373 mg kg-1, 65 mg kg-1. Depth ratios and multivariate statistical analysis suggested that Co, Ni and Mn have principal contribution of geogenic sources and Ba, Cr, Cu, Pb, V and Zn anthropogenic sources. The upper limit of background values estimated with median absolute deviation (MAD) method and DS samples were Ba 30 mg kg-1, Co 24 mg kg-1, Cr 22 mg kg-1, Cu 24 mg kg-1, Mn 662 mg kg-1, Ni 66 mg kg-1, Pb 1.5 mg kg-1, V 108 mg kg-1, and Zn 52 mg kg-1. Contamination factor showed that some soil sample were categorized as considerable contamination to very high contamination for Pb, Zn and V. Both Hazard index and cancer risk indicated no adverse health effects.Keywords: Heavy metals, urban soils, ecological indices, health risk assessment

Mediterranean coastal areas have been cultivated for long time. Wetlands areas situated near to the coast have been drainaged by using drainage channels. Heavy metals can be transferred from soils to the channels under agricultural management practices, especially under flood and furrow irrigation (the most important in the area studied). Anthropogenic inputs, including excessive use of agrochemicals and manure, in agricultural soils contribute to an increase of the content of some toxic heavy metals [1].The agricultural area situated in the South of the province of Alicante has an important drainage system (avoiding to be a coastal wetland), which more than a thousand kilometers that allow the cultivation on calcareous soils (mainly Fluvisols). However, land uses have been changing and an important transformation of rural areas to residential areas have been occurred in the recent decades.Under this situation, the presence of Cd, Cr and Ni in drainaged waters derived from infiltration from agricultural soils, and runoff from some urban areas, have been checked in the main drainage system (13 drainage channels) in order to detect possible influences of soil management in metal pollution. Water samples were taking along the channels in three to ten points of each channel, depending on the length, and metals were analyzed following standard methods [2]. At the same time, the land cover has been analyzed by using the last data from National Aerial Orthophotography Plan (available from the National Center of Geographical Information, Spain).The most important result obtained was that the presence of Cd in the waters was under the limit of detection of 0.1 μg/L. This result reflected the absence of pollution sources of this metal from soils to these drainage channels.Moreover, in the case of Cr, the values obtained were even below the reference values ​​for drinking water [3]. However, the major concentrations of this metal were between 6 to μg/L in only 4 channels. Ni, whose concentrations were lower than those for Cr, has values under 7 μg/L. Heavy metal pollution, at least in the elements analyzed, does not seem to be a serious problem in terms of the quality of these waters.Although many land cover changes have occurred, most of the soils are dedicated to agriculture. On the other hand, no clear effects related to the proximity of urban areas to the drainage channels have been observed. KeywordsHeavy metals; irrigation; land cover changes, pollution, wetlands. References[1] Navarro-Pedreño, J.; Almendro-Candel, M.B.; Gómez, I.; Jordan, MM; Bech, J.; Zorpas, A.A. (2018). Trace metal content and availability of essential metals in agricultural soils of Alicante (Spain). Sustainability 10, 4534. [2] APHA, AWWA, WEF (2012). Standard Methods for the examination of water and wastewater. Ed. American Public Health Association, Washington.[3] Real Decreto 314/2016, de 29 de julio, por el que se modifican el Real Decreto 140/2003, de 7 de febrero, por el que se establecen los criterios sanitarios de la calidad del agua de consumo humano.

Urban areas are constantly growing. By 2050, the urban world population, it is predicted to reach 6 billion. Being component of cities environment, urban soils have elevated levels of potentially toxic elements from anthropogenic action. The aims of this study are (1) to establish background levels of potentially toxic element in soils in the city of Coronel and (2) to assess the pollution and identify its origin. Samples (129 in total) were collected in Coronel, from 43 sites in schoolyards. Three samples were taken at each site: 0–10 cm, 10–20 cm and 150 cm depth. Principal component analysis (PCA), cluster analysis (CA) and depth ratios were applied to distinguish the origin of the contamination. The geoaccumulation index, contamination factor and the integrated pollution index were used to estimate the pollution. The median concentration of the chemical elements in 0–10 cm depth was Ba 38 mg kg−1; Co 15 mg kg−1; Cr 18 mg kg−1; Cu 22 mg kg−1; Mn 536 mg kg−1; Ni 35.5 mg kg−1; Pb 6 mg kg−1; V 94 mg kg−1; Zn 65 mg kg−1. Principal component analysis and CA suggested that Co, Ni and Mn were mainly derived from geogenic origin, while Ba, Cr, Cu, Pb, V and Zn from anthropic origin. Contamination factor indicated that some soil samples were classified as considerable contaminated to very highly contaminated by Ba, Pb, Zn and V.

The aim of this study was to estimate the phytoremediation potential of Brassicaceae plant species growing on mineralized and contaminated soils. The concentrations of six potentially toxic metals (Cd, Cu, Co, Ni, Pb and Zn) in the soils and plants collected from four mining areas of the Karachay-Cherkesia and the Dagestan (the North Caucasus, Russia) were determined. Mine soils showed high acid-soluble and extractable concentrations of: Cu, Zn, at Urup copper ore mining area; Ni, in the Beden serpentine quarry; and Zn and Pb around Kurush-Mazin polymetallic ores. Results demonstrated that metal concentrations in soils were in general above the Russian maximum permissible values. In all studied areas, Brassicaceae were pioneer species, and revealed a high tolerance to soils with high concentrations of potentially toxic metals. Different degrees of accumulating capacity were found in the studied Brassicacaeae species: hyperaccumulation of Ni in Alyssum murale, and significant accumulation of several metals in Arabis sagittata. These species can be used in a cost-effective process of phytoextraction. They are promising species for rehabilitation of degraded and/or contaminated soils of the North Caucasus.

The present study summarizes the results of investigations of the trace element distribution in soils and their uptake by plants of natural habitats on the ultramafic and acidic rocks of the Polar Urals and Chukotka in the Arctic Russia. Concentrations of Fe, Mn, Zn, Cu, Ni, Cr, and Co were determined by atomic absorption spectrometry in 194 plant species of 30 families and 157 soil samples. Two leaches were used for the soil – 1 M ammonium acetate (exchangeable) and 1 M HNO3 (acid soluble); a mixture of 1.5 M HNO3 and 3.7 M HCl was used for the plants. The levels of Fe, Cr and especially Ni in the soils on the ultramafic rocks exceeded those of soils on the acidic rocks. The mineral composition of plant species varies depending on the differences in chemical and mineralogical composition of the two soil-forming rock types. Taxon-specific features in the accumulation of potentially toxic elements in plants of these regions have been revealed for the first time. The data on the metal accumulation ability of plant species show that the species Thlaspi cochleariforme DC. and Alyssum obovatum (C.A. Mey) Turcz. (Brassicaceae) could be considered as Ni hyperaccumulators. These species could therefore have potential for Ni phytoextraction from contaminated soils.

The objective of this study is to ascertain the spatial distribution of Cu, Pb and Zn in order to determine the degree of contamination in urban soils from Talcahuano (Chile) and to identify the influence of possible contamination sources. A total of 420 samples were collected from the study area based on the following criteria: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm) and 140 deep soil samples (DS) (150 cm). The soils were characterized for their physical characteristics such as grain size distribution, pH, organic matter content etc. and the concentrations of Cu, Pb and Zn were analyzed by Atomic Absorption Photospectrometry following Aqua Regia digestion. Correlations combined with spatial analysis were implemented in order to distinguish the sources of the trace metals and whether they are geogenic or anthropogenic of origin. Several simple and robust statistical methods were applied to the data sets in order to evaluate useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factors and contamination factors were also evaluated. The median concentrations obtained for the studied trace metals includes: Cu 23.1 mg kg − 1 , Pb 10.2 mg kg − 1 and Zn 56.7 mg kg − 1 . In general, the concentrations of Cu, Pb and Zn decrease with depth however, in certain sites the subsoil samples (SS) levels show higher concentrations than topsoil samples (TS). A possible explanation could be related to the uncontrolled clandestine landfill sites using both construction material debris and/or industrial solid wastes. Correlation analysis suggests that Cu, Pb and Zn are contributed by external sources. The spatial distribution of Cu, Pb and Zn in topsoil samples (TS) displays a spatial pattern extending along major roadway environments and emission sources. Estimated background values determined with the iterative 2σ-technique yields 43.7 mg kg − 1 for Cu, 17.5 mg kg − 1 for Pb and 91.7 mg kg − 1 for Zn respectively. The geochemical index, enrichment factor and the contamination factor all register a moderate to high contamination level in some of the soil samples.

Underground coal mining in Southern European Russia leads to soil cover destruction in areas directly occupied by spoil tips and rock dumps located nearby. Coal producing areas in Rostov Oblast were selected for a detailed consideration. Soil samples were taken from the uppermost horizons: a layer of 0–10 cm of spoil tips and surrounding areas, as well as from 1.5 m depth vertical soil profiles. The soil samples were analysed for mineral composition, particle-size distribution and gross contents of Cu, Zn, Pb, Ag, Sn, Mo, Ba, Co, Ni, Mn, Ti, V, Cr, Ga, P, Li, Sr, Y, Yb, Nb, Sc and Zr, using emission spectral analysis. The plant species of mining influenced areas were described. The process of Technosol formation at the waste sites was considered separately. Soils have not yet formed as a result of a self-restoration on the spoil tips aged more than 50 years and burnt-out decades ago. A vegetation cover, which emerged during this time range, practically does not support the progress of any considerable soil-forming process. The ponds formed by the flooding of burning spoil tips, do not give the possibility for the formation of soils and hardly contribute to plant growth. The surface layers of spoil tips at all stages of their development are different from the surrounding steppe soils in geochemical characteristics and mineralogical composition. The atmospheric and water inflow of material from spoil tips changes (in the cases studied - worsens) a state of steppe soils within a radius of 1 km, and leads to the increase of heavy metal content in these soils.

The objectives of this study were (1) to determine the concentrations and background concentrations of Ba, Co, Cr, Mn, and Ni in the urban soils of Talcahuano (Chile); (2) assess the level of contamination in the urban soils based on different pollution indexes; and (3) to identify natural or anthropogenic sources in order to obtain a spatial distribution of the pollutants. A total of 420 samples were collected from the study area as follows: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm), and 140 deep soil samples (DS) (150 cm). The soils were characterized, and the concentrations of Ba, Co, Cr, Mn, and Ni were analyzed by atomic absorption photospectrometry following aqua regia digestion. Correlations and principal component analysis combined with spatial analysis were implemented in order to distinguish the sources and their classification as geogenic or anthropogenic. Several simple and robust statistical methods were applied to datasets in order to explore their potential in the evaluation of a useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factor, and contamination factor were also evaluated. The median concentrations obtained for various elements includes Ba 461 mg kg−1, Co 82.7 mg kg−1, Cr 134 mg kg−1, Mn 311 mg kg−1, and Ni 56.1 mg kg−1. In general, the concentrations of Ba, Co, Cr, Mn, and Ni decrease with depth. Correlations and principal component analysis suggest that Cr, Mn, and Ni are contributed by external sources. The spatial distribution of Cr, Mn, and Ni in TS displays a spatial pattern extending along industrial environments and emission sources. The estimated background values determined with the iterative 2σ-technique includes 536 mg kg−1 for Ba, 95.9 mg kg−1 for Co, 208 mg kg−1 for Cr, 464 mg kg−1 for Mn, and 90.5 mg kg−1 for Ni. The geochemical index, enrichment factor, and the contamination factor register a moderate to considerable contamination in some soil samples.

This article analyzed the survival of Escherichia coli, total coliforms, and Salmonella spp. in a soil amended with urban sewage sludge due to its potential use in soil rehabilitation and to the risk of microbial pollution. The survival of E. coli, total coliforms, and Salmonella spp. was determined in a soil amended with different doses of four different urban sewage sludge based on equivalent nitrogen fertilization of 0, 85, 170, and 340 kg N/ha. After the topsoil/sludge mixtures were made, they were wet to 18% moisture and analyzed for 2 months to determine the presence of bacteria, and then again after 1 year. The results indicate that the presence of microorganisms was strongly conditioned by the type of biosolid and the dose applied. Soil moisture diminished as the experiment progressed and seemed to play a role in controlling the presence of the bacteria. The initial concentrations of bacteria depend on the sewage sludge treatment. The evolution of E. coli had a similar trend as total coliforms, and Salmonella spp. was absent after 8 weeks although a positive presence was detected in some soils after a year. As a conclusion, long periods of time reduce the risk from the presence of pathogens in soils, and the persistence may be closely related to the treatment of sewage sludge and the initial amount of microorganisms in the sewage sludge.