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The existence of enormous volumes of mine tailings (MTs) deposits around the World, and specially in Chile, has generated a growing interest about the potential economic and socio-environmental benefits of reprocessing them. The present study assesses this possibility in the world class example of Mineral Valle Central (MVC), one of the few MTs reprocessing plants that has been under operation since 1992. To do so, 20 sampling points along the mineral processing plant were selected and monitored every two months from April 2018 to January 2019, generating a total of 120 samples. The multivariate statistical analysis of detailed chemical and mineralogical information confirmed the existence of two main groups, a first one corresponding to the elements (As, Ag, Fe, Cd, Co, Ni, Pb, Sb and Zn) linked to sulphides and a second one including elements mainly hosted by silicates. As expected, the first group of elements showed a general increasing tendency in their concentration along the processing plant while the second group tended to decrease their concentrations. It was observed that during the generation of the current Cu-concentrate in MVC, Co concentrations are increased as high as ten times (~0.25 g/kg) from the original concentration in the MTs entering the reprocessing plant (~0.025 g/kg). Therefore, the design and theoretical addition of new operational units to generate pyrite concentrates was evaluated. Such a de-pyritization process unit could link economic and environmental potential benefits thanks to the recovery of the Co hosted in pyrite and to the reduction of the acid generation potential of the final MTs sent to Caren MTs deposit. This exploratory study shows important environmental benefits as well as some economic potential thanks to the recovery of Co hosted in pyrite. Notwithstanding, future comprehensive Co deportment studies and a detailed technical – economical evaluation are needed to determine the economic feasibility for the construction of

Introduction Social vulnerability is a known determinant of health in respiratory diseases. Our aim was to identify whether there are socio-demographic factors among COVID-19 patients hospitalized in Spain and their potential impact on health outcomes during the hospitalization. Methods A multicentric retrospective case series study based on administrative databases that included all COVID-19 cases admitted in 19 Spanish hospitals from 1 March to 15 April 2020. Socio-demographic data were collected. Outcomes were critical care admission and in-hospital mortality. Results We included 10,110 COVID-19 patients admitted to 18 Spanish hospitals (median age 68 (IQR 54–80) years old; 44.5% female; 14.8% were not born in Spain). Among these, 779 (7.7%) cases were admitted to critical care units and 1678 (16.6%) patients died during the hospitalization. Age, male gender, being immigrant, and low hospital saturation were independently associated with being admitted to an intensive care unit. Age, male gender, being immigrant, percentile of average per capita income, and hospital experience were independently associated with in-hospital mortality. Conclusions Social determinants such as residence in low-income areas and being born in Latin American countries were associated with increased odds of being admitted to an intensive care unit and of in-hospital mortality. There was considerable variation in outcomes between different Spanish centers.

The aim of this work was to make an estimate of the remaining metal resources of the Haveri tailings (SW Finland) that were deposited for 60 years ago. We used existing databases (Cu, Zn, Ni, Co, As, Pb, Ag, Au, Fe, S) of previous valorization performed in the 1980's with high sample density; a total of 1201 tailings samples from 165 drill cores. Cobalt, Cu, and Au were chosen for further statistical evaluation, 3D block modelling, and feasibility analysis. We performed also a volume estimate of the tailings based on the depth of drill cores, which was used for the calculation of the total resources. The grade and total tonnage of remaining Au resources present economic potential in comparison to current Au production, whereas the remaining resources for Co and Cu are less promising for reprocessing. However, further feasibility studies are required. This work may serve as an example to make use of existing databases by means of geostatistical modelling techniques in combination with more profound understanding of the mineralogical associations of the metals.

We have studied the metal air pollution trends in a medium-sized Spanish city suffering from traffic emission using in-situ lichen Xanthoria parietina as a bioindicator. The large scale sampling included 97 samples from urban, metropolitan and remote control areas of Granada that were analyzed by Inductively Coupled Plasma-Mass Spectrometry. Enrichment factor of Sb exhibited severe anthropogenic enrichment, whereas Cu and Sb showed significantly higher median values in the urban areas with respect to metropolitan areas. Additionally, bioaccumulation ratios of V, Cr, Ni, Cu, Zn, Cd, Sb, and Pb —associated to exhaust and non-exhaust traffic emissions— enabled us to delineate hot spots of metal(loid) accumulation in the main accesses to the city, characterized by dense traffic and copious traffic jams. To distinguish non-exhaust emissions, we studied the spatial distribution of the Cu:Sb ratio —a tracer of brake wear— highlighting the surroundings of the highway and the main traffic accesses to the city likely due to sudden hard braking and acceleration during frequent traffic jams. Our study shows that the metal(loid) contents in lichens are excellent proxies for non-exhaust traffic emissions and that their contribution to the metal(loid) air pollution in Granada is more significant than previously thought. A large scale sampling of X. parietina in a polluted city unveils previously unrecognized non-exhaust emission hotspots with Sb as an outstanding proxy for monitoring in urban areas.

Salt marshes are natural deposits of heavy metals in estuarine systems, where sulphide precipitation associated with redox changes often results in a natural attenuation of contamination. In the present study, we focus on the effects of variable redox conditions imposed to a highly-polluted phosphogypsum stack that is directly piled over the salt marsh soil in the Tinto River estuary (Huelva, Spain). The behaviour of contaminants is evaluated in the phosphogypsum waste and in the marsh basement, separately, in controlled, experimentally-induced oscillating redox conditions. The results revealed that Fe, and to a lesser extent S, control most precipitation/dissolution processes. Ferric iron precipitates in the form of phosphates and oxyhydroxides, while metal sulphide precipitation is insignificant and appears to be prevented by the abundant formation of Fe phosphates. An antagonistic evolution with changing redox conditions was observed for the remaining contaminants such as Zn, As, Cd and U, which remained mobile in solution during most of experimental run. Therefore, these findings revealed that high concentrations of phosphates inhibit the typical processes of immobilisation of pollutants in salt-marshes which highlights the elevated contaminant potential of phosphogypsum wastes on coastal environments.

Here, we validated a protocol for the elemental analysis of plant and food materials using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and pressed pellets in compliance with the Green Chemistry principles, i.e. avoiding the use of hazardous reagents. The protocol included sample pre-treatment, preparation of pellets, and LA-ICP-MS optimisation for the food sample matrix using leaf certified reference materials. Sample homogenisation and particle size reduction (∼10 µm) for samples with larger initial particle sizes proved crucial in improving signal stability and analytical results, whereas the raster mode was preferred over spot mode for greater accuracy. The validation of the technique was successful for determination of Mn, Ni, Cu, Zn, As, Se, Cd and Pb (z-score values ≤2). We propose LA-ICP-MS using pressed pellets as an alternative to ICP-MS in food analysis.

Extreme concentrations of potentially toxic elements in lichens in urban areas surrounding industrial estates imply severe air pollution and a potential health risk to residents.Huelva is a highly industrialized city in SW Spain hosting, among others, a Cu smelter, a phosphate fertilizer plant, a power plant, and oil refineries. This study aims to evaluate metal concentrations in lichens as bioindicators of atmospheric pollution in the impacted urban areas. Xanthoria parietina species from Huelva and nearby villages, as well as reference samples from remote, non-contaminated urban areas, were analyzed for trace elements (V, Cr, Mn, Co, Ni, Cu, Zn, Sr, As, Cd, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Er, Tm, Yb, Lu, Pb, Th, U) using Inductively Coupled Plasma-Mass Spectrometry; and for major elements (Ca, K, Mg, P, and S) by Inductively Coupled Plasma-Optical Emission Spectrometry after acid digestion. The metal composition of X. parietina exhibits spatial distribution patterns with extremely elevated concentrations (Co, Ni, Cu, Zn, As, Cd, Sb, Ba, Pb, U, and S) in the surroundings of the industrial estates to <1 km distance. Mean concentrations were significantly lower in the urban areas >1 km from the pollution sources. However, air pollution persists in the urban areas up to 4 km away, as the mean concentrations of Cu, Zn, As, Cd, Sb and S remained considerably elevated in comparison to the reference samples. Though rigorous source apportionment analysis was not the aim of this study, a good positive correlation of our results with metal abundances in ambient particulate matter and in pollution sources points to the Cu smelter as the main source of pollution. Hence, the severe air pollution affecting Huelva and nearby urban areas may be considered a serious health risk to local residents.

Black shales are sedimentary rocks containing >0.5% of organic carbon. They host polymetallic deposits which have been mined for Cu, Ni, Zn, Mn, P, Mo, V, U, Au and PGE (platinum group elements). Even sub-economic occurrences provide potential risk of acid rock drainage when exposed to oxic surface environment. The natural acid neutralisation potential varies depending on the adjacent rock units, especially on the presence of calcareous rocks. The chemical and mineralogical composition of black shale is reflected in the quality of the surface waters and groundwater. Cu, Ni, Pb, U and Zn are recognised as major pollutants though the environmental impact is characteristically polymetallic just like the black shale occurrences. Hence, the environmental impacts have to be evaluated in each occurrence. The Proterozoic Ni–Zn–Cu–Co deposit at Talvivaara, Finland, is reviewed in more detail as an example of a large, low-grade deposit that is currently exploited with open pit mining and a bioleaching process, together with the Proterozoic Central African Copperbelt, the Cambrian U-Mo deposits in Sweden, the Cambrian Ni–Mo–PGE deposits in China and the Cambrian-Ordovician U deposits in South-Korea, the Devonian Ni–Zn–PGE occurrences in Yukon, Canada, and Kentucky, USA, and the Permian Cu-Ag deposits in Poland and Germany. The mineralised horizons may be merely few centimetres thick like in Yukon or hundreds of metres thick like at Talvivaara. Both natural and anthropogenic environmental impacts of black shales are reviewed world-wide, and based on the overview of the state-of-the-art an integrated research approach is suggested for the comprehensive assessment of the risk. Black shales are natural sources of soil and water contamination. At Talvivaara, the geochemical background includes higher than average concentrations of Ni, Cu, Zn and Mn in glacial till, peat, surface waters and groundwater as well as in stream and lake sediments. Bioaccumulation by plants has been repor

The Atrevida vein is located at the south-western edge of the Catalonian Coastal Ranges, Spain. This vein extends for more than 3 km and is hosted by Silurian and Carboniferous metasediments, late Hercynian granites and continental conglomerates of Lower Triassic age. The Silurian metasediments contain massive sulphide layers with disseminations of platinum-group element (PGE)-bearing, Fe-Ni arsenides. Vein filling largely consists of banded and brecciated baryte rimmed by a complex polymetallic assemblage of Co-Ni-As-Bi-Ag(-U) ores. The Ni arsenide and sulpharsenide assemblage occurs only where the vein cuts the sulphide-bearing Silurian metasediments, and consists of nickeline, maucherite, rammelsbergite, gersdorffite and Ni-skutterudite. These Ni arsenides and sulpharsenides display rosettes, spherules, colloform and botryoidal textures, as well as subhedral crystals. The chemical compositions of these arsenide-sulpharsenide minerals exhibit limited cation substitution but substantial anion substitution of As by S and Sb, exceeding the expected theoretical values at low temperatures. This suggests that most of them formed under disequilibrium conditions. Ni arsenides and sulpharsenides also contain trace PGE. Palladium (up to 157 ppm) is the most abundant PGE, and occurs in solid-solution in all the phases studied, but shows the highest values in rammelsbergite and Niskutterudite. Pt only occurs in massive nickeline (54-1338 ppm Pt) and in zoned gersdorffite (29-360 ppm Pt) formed at the end of the depositional sequence of arsenides. The Ni arsenide and sulpharsenide ores at the Atrevida mine formed by reduction of PGE-bearing, oxidizing fluids at temperatures close to, or slightly above 100°C. These oxidizing fluids most probably collected their PGE budget from the nearby mineralized black shales. During the crystallization of the veined, Ni arsenide and sulpharsenide ores, Pd partly concentrated in the early nickeline and maucherite, but mainly fractionated to