30 research outputs found
Cement encapsulation processes to mitigate the risks posed by different types of antimony-bearing mine waste
[EN]n this study cement encapsulation processes of different types of mine waste generated from the exploitation of Sb ore deposits were evaluated as a way to manage them and avoid further environmental pollution and the negative impact on surrounding ecosystems. For this purpose, Sb-bearing mine waste rocks, mine tailings, and smelting waste were subjected to cementation processes using Portland cement/calcium hydroxide as binder and different binder:mine waste ratios (10:90–80:20 wt%). The encapsulated materials were characterized for their mechanical behavior (compressive strength test), leaching properties (batch shaking and tank leaching tests), and mineralogical and chemical composition by X-ray powder diffraction, scanning electron microscopy, and electron microprobe analysis. A binder:mine waste ratio of 40:60 wt% was found appropriate to decrease the leachable Sb concentrations at levels below the limit for acceptance at non-hazardous waste landfills. Diffusion was the main mechanism controlling Sb leaching. The obtained effective diffusion coefficients and developed compressive strengths indicate that the encapsulated materials were suitable for disposal. Therefore, according to their leaching and strength characteristics, the encapsulated mine wastes derived using the indicated conditions could be deposited at landfills for non-hazardous waste, thus minimizing the environmental hazards caused by their accumulation in the mine surrounding areas. Additionally, according to the Dutch legislation on the use of waste materials in the built sector, some formulations of encapsulated mine tailings already met the Sb leaching requirement for open (un-insulated) construction applications. Therefore, Sb-bearing mine wastes, especially mine tailings, also present a great potential to be recycled as substitutes for natural aggregates in concrete in construction applications. Antimony was mostly preserved in the original Sb-bearing phases [Fe and Sb (oxyhydr)oxides and tripuhyite] after the encapsulation processes. Of compounds resulting from the hydration of Portland cement, C-(A)-S-H phases predominated, having an important role in attenuating the Sb release from the different types of mine waste; average Sb2O5 contents of 0.12–0.31 wt% were found in C-(A)-S-H phases
Arsenic distribution in a pasture area impacted by past mining activities
[EN]Former mine exploitations entail a serious threat to surrounding ecosystems as after closure of mining activities their unmanaged wastes can be a continuous source of toxic trace elements. Quite often these mine sites are found within agricultural farming areas, involving serious hazards as regards product (feed/food) quality. In this work a grazing land impacted by the abandoned mine exploitation of an arsenical deposit was studied so as to evaluate the fate of arsenic (As) and other trace elements and the potential risks involved. With this aim, profile soil samples (0–50 cm) and pasture plant species (Agrostis truncatula, Holcus annus and Leontodon longirostris) were collected at different distances (0–100 m) from the mine waste dump and analyzed for their trace element content and distribution. Likewise, plant trace element accumulation from impacted grazing soils and plant trace element translocation were assessed. The exposure of livestock grazing animals to As was also evaluated, establishing its acceptability regarding food safety and animal health. International soil guideline values for As in grazing land soils (50 mg kg−1) resulted greatly exceeded (up to about 20-fold) in the studied mining-affected soils. Moreover, As showed a high mobilization potential under circumstances such as phosphate application or establishment of reducing conditions. Arsenic exhibited relatively high translocation factor (TF) values (up to 0.32–0.89) in pasture plant species, reaching unsafe concentrations in their above-ground tissues (up to 32.9, 16.9 and 9.0 mg kg−1 in Agrostis truncatula, Leontodon longirostris and Holcus annus, respectively). Such concentrations represent an elevated risk of As transfer to the high trophic-chain levels as established by international legislation. The limited fraction of arsenite found in plant roots should play an important role in the relatively high As root-to-shoot translocation shown by these plant species. Both soil ingestion and pasture intake resulted important entrance pathways of As into livestock animals, showing quite close contribution levels. The cow acceptable daily intake (ADI) of As regarding food safety was surpassed in some locations of the study area when the species Agrostis truncatula was considered as the only pasture feed. Restrictions in the grazing use of lands with considerable As contents where this plant was the predominant pasture species should be established in order to preserve food quality. Therefore, the exposure of livestock animals to As via both soil ingestion and pasture consumption should be taken into account to establish the suitability of mining-impacted areas for gazing
Antimony distribution and mobility in different types of waste derived from the exploitation of stibnite ore deposits
[EN]Wastes derived from the exploitation of stibnite ore deposits were studied to determine their mineralogical, chemical, and environmental characteristics and establish the Sb distribution and the current and long-term risks of Sb mobilization. Representative samples of mine waste rocks, mine tailings, and smelting waste were studied by X-ray powder diffraction, polarized light microscopy, electron microprobe analysis, and digestion, leaching, and extraction procedures. The main Sb-bearing minerals and phases identified in the smelting waste were natrojarosite, iron (oxyhydr)oxides, mixtures of iron and antimony (oxyhydr)oxides, and tripuhyite; those in the mine tailings and mine waste rocks were iron (oxyhydr)oxides and/or mixtures of iron and antimony (oxyhydr)oxides. Iron (oxyhydr)oxides and natrojarosite had high Sb contents, with maximum values of 16.51 and 9.63 wt% Sb2O5, respectively. All three types of waste were characterized as toxic; the mine waste rocks and mine tailings would require pretreatment to decrease their leachable Sb content before they would be acceptable at hazardous waste landfills. Relatively little of the Sb was in desorbable forms, which accounted for <0.01 and <0.8% of the total Sb content in the smelting waste and mine waste rocks/mine tailings, respectively. Under reducing conditions, further Sb mobilization from mine waste rocks and mine tailings could occur (up to 4.6 and 3.3% of the total content, respectively), considerably increasing the risk that Sb will be introduced into the surroundings. Although the smelting waste had the highest total Sb content, it showed the lowest risk of Sb release under different environmental conditions. The significant Fe levels in the smelting waste facilitated the formation of various Fe compounds that greatly decreased the Sb mobilization from these wastes
Whole-exome sequencing reveals ZNF408 as a new gene associated with autosomal recessive retinitis pigmentosa with vitreal alterations
Retinitis pigmentosa (RP) is a group of progressive inherited retinal dystrophies that cause visual impairment as a result of photoreceptor cell death. RP is heterogeneous, both clinically and genetically making difficult to establish precise genotype–phenotype correlations. In a Spanish family with autosomal recessive RP (arRP), homozygosity mapping and whole-exome sequencing led to the identification of a homozygous mutation (c.358_359delGT; p.Ala122Leufs*2) in the ZNF408 gene. A screening performed in 217 additional unrelated families revealed another homozygous mutation (c.1621C>T; p.Arg541Cys) in an isolated RP case. ZNF408 encodes a transcription factor that harbors 10 predicted C2H2-type fingers thought to be implicated in DNA binding. To elucidate the ZNF408 role in the retina and the pathogenesis of these mutations we have performed different functional studies. By immunohistochemical analysis in healthy human retina, we identified that ZNF408 is expressed in both cone and rod photoreceptors, in a specific type of amacrine and ganglion cells, and in retinal blood vessels. ZNF408 revealed a cytoplasmic localization and a nuclear distribution in areas corresponding with the euchromatin fraction. Immunolocalization studies showed a partial mislocalization of the p.Arg541Cys mutant protein retaining part of the WT protein in the cytoplasm. Our study demonstrates that ZNF408, previously associated with Familial Exudative Vitreoretinopathy (FEVR), is a new gene causing arRP with vitreous condensations supporting the evidence that this protein plays additional functions into the human retina.This work is supported by CIBERER (06/07/0036), FIS (PI013/00226), Ministry of Economy and Competitiveness-FEDER (BFU2012-36845), RETICS (RD12/0034/0010), Fundación ONCE, Fundaluce and grants BIO2011-27069 from the Spanish Ministry of Economy and Competitiveness, and PROMETEOII/2014/025 from the Conselleria de Educacio of the Valencia Community. PC is supported by Fundación Conchita Rábago (FCR), MC by Miguel Servet ISCIII (CP/03256) and dS by CAPES Foundation, Ministry of Education of Brazil
Genetic landscape of 6089 inherited retinal dystrophies affected cases in Spain and their therapeutic and extended epidemiological implications
Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations.This work was supported by the Instituto de Salud Carlos III (ISCIII) of the Spanish Ministry of Health (FIS; PI16/00425 and PI19/00321), Centro de Investigación Biomédica en Red Enfermedades Raras (CIBERER, 06/07/0036), IIS-FJD BioBank (PT13/0010/0012), Comunidad de Madrid (CAM, RAREGenomics Project, B2017/BMD-3721), European Regional Development Fund (FEDER), the Organización Nacional de Ciegos Españoles (ONCE), Fundación Ramón Areces, Fundación Conchita Rábago and the University Chair UAM-IIS-FJD of Genomic Medicine. Irene Perea-Romero is supported by a PhD fellowship from the predoctoral Program from ISCIII (FI17/00192). Ionut F. Iancu is supported by a grant from the Comunidad de Madrid (CAM, PEJ-2017-AI/BMD7256). Marta del Pozo-Valero is supported by a PhD grant from the Fundación Conchita Rábago. Berta Almoguera is supported by a Juan Rodes program from ISCIII (JR17/00020). Pablo Minguez is supported by a Miguel Servet program from ISCIII (CP16/00116). Marta Corton is supported by a Miguel Servet program from ISCIII (CPII17/00006). The funders played no role in study design, data collection, data analysis, manuscript preparation and/or publication decisions
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
Soil Remediation in Mining Polluted Areas
Número 10 (2008): Comunicaciones del Workshop: “Problemática Postminera derivada de la explotación de Sulfuros Polimetálicos", Sevilla 17-19 de Noviembre de 2008. Conferencias Invitadas{ENG}The sorbent behaviour of palygorskite with respect to lead, copper, zinc and cadmium and that of sepiolite with respect to zinc and cadmium
was studied in order to consider their application to remediate soils polluted with these metals. The soluble metal concentrations
as well as the readily-extractable metal concentrations were substantially decreased at any concentration of minerals applied to soil (1,
2, 4%), although the highest decrease is obtained at the 4% dose. The column studies also showed a high reduction in the metal leaching
(50% for lead, 59% for copper, 52% for zinc and 66% for cadmium) when a palygorskite dose of 4% was applied. Sepiolite also
showed a high reduction in the leaching of cadmium and zinc (69 and 52%, respectively).The use of zeolitic material synthesized from
coal fly ash for the immobilization of metals in contaminated soils in the Guadiamar valley (El Vicario farm) was also studied. The results
showed that the zeolitic material considerably decreased the leaching of Cd, Co, Cu, Ni, and Zn. This immobilization could be a consequence
of the rise in pH from 3.3 to 7.6 due to the alkalinity of the zeolitic material added (caused by traces of free lime in the fly ash,
or residual NaOH from zeolite synthesis). The adsorption of As(V) by some natural Fe oxyhydroxides and clay minerals and synthetic
Al(OH)3 and FeOOH was also studied. The results showed a very high As(V) adsorption capacity on both synthetic Al hydroxide (122
mg/g at pH: 5) and Fe oxyhydroxide (76 mg/g at pH 5). The application of these adsorbents to arsenic immobilization in the remediation
process of two polluted mining soils with some differences in their physicochemical characteristics was also studied. The best
results were obtained when synthetic Al(OH)3 and FeOOH were used; these materials decreased the water-extractable fraction of As by
55-79% for one soil and by nearly 100% for the other soil, the latter with higher pH and Eh values.{ESP}En este trabajo se ha estudiado el comportamiento como sorbente de la paligorskita en relación con el plomo, cobre, zinc y cadmio
y de la sepiolita respecto del zinc y el cadmio. Ambos substratos minerales han sido considerados en la remediación de suelos
contaminados por esos metales. Los experimentos muestran que las concentraciones de metal soluble así como las de metales
lábiles disminuyen significativamente considerando cualquier concentración de los substratos estudiados (1, 2, 4%), aunque la
máxima reducción se obtenía para dosis del orden del 4%. Los experimentos en columna también pusieron en evidencia una elevada
reducción en la lixiviación de metales (50% para el plomo, 59% para el cobre, 52% para el zinc y 66% para el cadmio) cuando
se aplicó una dosis del 4 % de paligorskita. La sepiolite también mostró una elevada reducción en la lixiviación de cadmio y zinc
(69 y 52%, respectivamente). También se ha estudiado la capacidad de inmovilización de metales en suelos contaminados (del
valle del Guadiamar, granja de El Vicario). Los resultados muestran que los materiales zeolíticos disminuyeron notablemente la lixiviación
de Cd, Co, Cu, Ni y Zn. Esta inmovilización puede ser el resultado de la subida del pH desde 3.3 a 7.6 resultante de la alcalinidad
de los materiales zeolíticos (trazas de cal libre en las cenizas o NaOH residual de la síntesis de las zeolitas). También se
ha estudiado la adsorción de As(V) por parte de algunos oxihidróxidos de Fe naturales, por minerales de la arcilla y por Al(OH)3 y
FeOOH sintéticos. Los experimentos muestran una muy elevada capacidad de adsorción del As(V) tanto en el hidróxido de aluminio
sintético (122 mg/g a pH 5) como en el oxihidróxido de Fe (76 mg/g a pH 5). Ambos adsorbentes fueron aplicados in situ para
la remediación de dos emplazamientos con suelos contaminados por arsénico. Los mejores resultados se obtuvieron cuando se
utilizaron el Al(OH)3 y FeOOH sintéticos; Entre ambos redujeron entre un 55 y un 79 % de la fracción lixiviable (por agua) de uno de
los suelos, y cerca del 100% en el otro, aunque en éste último el pH y el Eh eran más elevados.Peer reviewe
Caracterización ambiental de la zona de explotación minera de Salava mediante bioindicadores
25 páginas, 3 figuras, 16 tablasLos objetivos del estudio son: Realizar la caracterización ambiental de suelos en zonas del área de Salave, y valorar el uso de productos de colmena (miel y polen) como indicadores de la calidad ambiental de dichas zonasN
Stabilization and encapsulation of arsenic-/antimony-bearing mine waste: Overview and outlook of existing techniques
34 páginas, 5 figuras, 1 tablaArsenic and antimony are metalloids that exhibit similar geochemical behavior and are often found in the same mineral associations, co-occurring in mine waste derived from ore exploitation. Due to their adverse effects on ecosystems and human health, techniques to limit their release into the environment from mine wastes and the consequent pollution of surrounding areas are of great interest. This review addresses the geochemical behavior of these two metalloids in mining environments and presents an overview of the main strategies used to stabilize or encapsulate As- or Sb-bearing mine waste, highlighting and comparing their shortcomings and advantages. Several approaches have been investigated, including the 1) establishment of surface covers, 2) application of amendments, 3) solidification using cementing or geopolymer, and 4) application of protecting coatings. Several of these methods have exhibited potential for treating As mine waste. However, the weathering state, composition, and final fate of wastes are determining factors affecting treatment effectiveness. Regarding Sb mine waste, only cementation processes have shown some good performance. Further research effort is required to develop effective passivating coatings or stabilization methods to treat these mine wastes.The present work was carried out under the framework of the project TERMET (Grant number: RTI2018-095433-B-I00) funded by Ministerio de Ciencia, Innovación y Universidades (MCIU), Spain/Agencia Estatal de Investigación (AEI), Spain/Fondo Europeo de Desarrollo Regional (FEDER), UE.Peer reviewe