There are few well-established risk factors for childhood leukemias. While the frequency of childhood leukemias might be partially attributable to some diseases (accounting for a small fraction of cases) or ionizing radiation, the role of heavy metals has not been assessed. The objective of our study was to assess the potential association between levels of cadmium (Cd) and lead (PB) in soil and childhood leukemias incidence. We conducted a population-based case–control study of childhood leukaemia in Spain, covering 2897 incident cases gathered from the Spanish Registry of Childhood Tumours and including 14 Spanish Regions with a total population of 5,307,433 children (period 1996–2015). Cd and Pb bioavailable levels at every children’s home address were estimated using data from the Geochemical Atlas of Spain. We used logistic regression to estimate odds ratios (ORs) and their 95% confidence intervals (95%CIs); we included as covariates: sex, rurality, employment rate and socioeconomic status. Metal levels were analysed according to two definitions: as continuous variable assuming linearity and as categorical variables to explore a potentially nonlinear association (quantiles). Increases in both Cd and Pb topsoil levels were associated with increased probability of childhood leukemias incidence. The results for the models with the continuous variables showed that a unit increase on the topsoil level was associated with an OR of 1.11 for Cd (95%CI 1.00–1.24) and an OR of 1.10 for Pb (95%CI 0.99–1.21). Our study may point towards a possible link between residential Cd and Pb topsoil levels and the probability of childhood leukemias incidence. Residing in a location with the highest concentrations of these heavy metals compared to those locations with the lowest could increase the risk around a 20%, for both Cd and Pb.
The objectives of this research are: (1) to study the process of formation of efflorescence salt crusts (ESC) on the surface of tailings dams, (2) to evaluate the possibility of recovering critical metals and raw materials, and (3) to study its effectiveness as a tailings (MT) decontaminant. To achieve these objectives, the evaporation process of 3 columns containing a mixture of MT and distilled water was monitored under laboratory conditions. Two MT of the flotation process from the extraction of Pb-Zn were used, one from the Mazarrón mining district (MDM) and the other from the Cartagena-La Unión mining district (CLUDM). MT and ESC were analysed by particle size analysis, mineralogical and chemical composition, thermal analysis, pH, electrical conductivity, potential redox, gravimetric water content and suction. It is important to note that some critical metals according to the EU 2020 CRWs, list are present in the MT sample. A significant growth in Zn ESC concentration was observed during the experiment. The concentration in MDM ESC is 8% higher than in the MT and in the CLUDM ESC it is 10% higher than in the MT. These results, together with the fact that ESC is water soluble, indicate the great potential of ESC treatment for metal recovery and MT decontamination.
Previous studies have addressed the occurrence of Acid Rock Drainage (ARD) affecting La Silva stream due to the generation of large dumps of Middle Ordovician black shales during the construction of a highway close to El Bierzo (León, Spain). This ARD was characterized by sulphated acid waters with high concentration of heavy metals and anomalies in dissolved thorium (Th) and uranium (U). In the present study, we analyse in depth black shales and water, streambed sediments and precipitates of La Silva stream and its tributaries using different petrographic, mineralogical and geochemical approaches. Black shales, with average Th and U contents of 20 and 3 μg/g respectively contain disseminated detritic micro-grains of high weathering-resistant minerals, such as monazite and xenotime, that present smaller amounts of yttrium and rare earth elements (REY) and other elements as Ca, U, Th, Si and F. Results of the affected waters by ARD show an enrichment in dissolved Th, U and REY of several orders of magnitude with respect to natural waters. Sampled precipitates were mainly schwertmannite (Fe8O8(OH)8-2x (SO4)xO16•nH2O) and goethite (α–Fe³⁺O(OH)) that showed an enrichment of Th (up to 798 μg/g) and REY, due to the presence of dissolved anionic species (e.g. Th(SO4)3²⁻, REY(SO4)2⁻) that enables their adsorption. Furthermore, these black shales show a clear enrichment in REE (Rare Earth Elements) with respect to NASC (North American Shales Composite) normalized REE patterns. Likewise, normalized REE patterns of stream waters and precipitates clearly show convex curvatures in middle-REE (MREE) with respect to light- and something less than heavy-REE, indicating the trend towards MREE enrichment. These findings are essential to evaluate the impact of ARD of Mid Ordovician shales in the surrounding environment, and to start considering these site as potential source of REE and critical raw materials, activating a Circular Economy.
A new echinoid belonging to the genus Habanaster is described from the Western Pyrenees (Pamplona basin, Spain). Definition of Habanaster itzae nov. sp. is based on 16 well-preserved specimens that were collected from Lutetian levels (middle Eocene) of the Anotz Formation. These levels have been interpreted as deposited in low energy, hemipelagic conditions. Habanaster itzae nov. sp. is older than the single formerly known Caribbean species H. sanchezi that occurs in Priabonian (late Eocene) levels from the Consuelo and Jabaco formations. A phylogenetic analysis places Habanaster among the Ovulasteridae. The family is part of a clade, including also the Aeropsidae, that gathers micrasterid spatangoids adapted to offshore or bathyal muddy environments.
In the Esteros del Iberá Wetland Area (EIWA, NE Argentina), the southern sector of the transboundary Guarani Aquifer System (SAG) is overlain by the Ramsar listed Iberá Wetlands and several rivers, that combined extend across 37,930 km² and represent one of the largest freshwater systems on the South American continent. Previous hydrogeological studies encompassing the entire SAG proposed preferential discharge of groundwater of various origins and ages to the EIWA. In this study, a multi-tracer study using major ionic species, δ¹⁸O, δ²H and ²²²Rn was conducted in lagoons, rivers, wells, and boreholes in the EIWA to confirm if discharge from the transboundary SAG is contributing to the surface water system. End-member Mixing Analysis (EMMA) determined the existence of four main end-members: groundwater from the SAG, more saline groundwater from the deeper Pre-SAG, and two poorly mineralised end-members from shallow, Post-SAG. EMMA calculations clearly illustrated complex binary and ternary mixing patterns involving the four end-members and highlighted the role of geological structures, specifically regional steep faults, in controlling the mixing patterns. ²²²Rn activities allowed in-situ identification of preferential deep groundwater discharge into both surface waters and shallow groundwaters. These findings provide strong evidence for the widespread existence of upward flows along major faults in this sector of the SAG, inducing complex mixing flow patterns and explaining the presence of old groundwater in shallow aquifers. Mapping the sources of water and the hydrological interactions are relevant for improving water balance estimates and develop management policies towards the preservation of these wetlands.
It was with much interest that we read the comment made by Meco et al. (2022), regarding our work on "Range expansion of tropical shallow-water marine molluscs in the NE Atlantic during the last interglacial (MIS 5e): Causes, consequences and utility of ecostratigraphic indicators for the Macaronesian archipelagos". We welcome the discussion generated by our paper and appreciate the recognition of its complexity and broad scope. In our opinion, the arguments offered by Meco et al. (2022) do not contradict our conclusions. Nevertheless, we take this opportunity to address their critiques regarding our list of "ecostratigraphic indicators" and parts of our hypothesized range expansions. Meco et al. (2022) question some of the molluscs
Cueva de la Mora is a permanently stratified acidic pit lake with extremely high concentrations of heavy metals at depth. In order to evaluate the potential for in situ sulfide production, we characterized the microbial community in the deep layer using metagenomics and metatranscriptomics. We retrieved 18 high quality metagenome-assembled genomes (MAGs) representing the most abundant populations. None of the MAGs were closely related to either cultured or non-cultured organisms from the Genome Taxonomy or NCBI databases (none with ANI >95% and none with AAI > 46%). Despite oxygen concentrations that are consistently below detection in the deep layer, some archaeal and bacterial MAGs mapped transcripts of genes for sulfide oxidation coupled with oxygen reduction. Among these microaerophilic sulfide oxidizers, mixotrophic Thermoplasmatales archaea were the most numerous and represented 24% of the total community. Populations associated with the highest predicted in situ activity for sulfate reduction were affiliated with Actinobacteria, Chloroflexi, and Nitrospirae phyla, and together represented about 9% of the total community. These MAGs, in addition to a less abundant Proteobacteria MAG in the genus Desulfomonile, contained transcripts of genes in the Wood-Ljungdahl pathway. All MAGs had significant genetic potential for organic carbon oxidation. Our results indicate that novel acidophiles are contributing to biosulfidogenesis in the deep layer of Cueva de la Mora, and that in situ sulfide production is limited by organic carbon availability and sulfur oxidation.
Geodiversity is the variety of earth materials, forms and processes that constitute and shape the Earth planet. Therefore, geodiversity includes essential for developing nature-based solutions and must be adequately characterised. This research aims to evaluate the geodiversity of Mainland Ecuador by estimating a Geodiversity Index, which is the sum of five partial indexes (Lithological, Geomorphological, Paleontological, Pedological, and Mineral occurrences), in a 25 × 25 km grid. In addition, the study shows and analyses the geodiversity index map obtained as a basis for the development of policies for the use and conservation of geodiversity. The cartography developed generally illustrates the distribution of the geological diversity existing in Ecuador. Specifically, the ranges of the indices reached in the geodiversity map, including the medium, high, and very high categories, corresponding to 47.52% of the extension of Ecuador using the Pereira method and to 52.91% using the procedure proposed in this study. These special categories are located mainly along the Andes Mountain range and in the newly formed mountain ranges in the coastal zone. In addition, these categories defined in the geodiversity map coincide, spatially, with the main initiatives of geoparks and geo-routes catalogued in the country. The maps generated and the estimated indices represent relevant tools in territorial planning and calculated future geoconservation strategies. Furthermore, a series of initiatives are proposed to develop a policyfavouring the characterisation, use and protection of geodiversity.
Two new species of the genus Plecia (Diptera: Bibionidae) are described. The only occurrence of the genus Plecia in the Miocene amber of Dominican Republic was formerly identified as P. pristina, a species having previously been described in the Mexican Miocene fauna. The Dominican specimen is hereby studied again and attributed to a new species, Plecia jorgecaridadi n. sp., alongside another new species, Plecia surieli n. sp.
This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles (Goldman et al., 2021, https://doi.org/10.1002/essoar.10508554.1) in the Geomagnetism, Paleomagnetism, and Electromagnetism (GPE) section and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: Global collaboration, reproducibility, data sharing and infrastructure; Inclusive equitable, and accessible science: Involvement, challenges, and support of early career, BIPOC, women, LGBTQIA+, and/or disabled researchers; Community engagement, citizen science, education, and stakeholder involvement. Data sharing practices and open repository use still varies strongly between GPE communities. Some have a long tradition of data sharing; others are only starting it. Globally, GPE leadership is strongly dominated by white males and diversity may increase through the creation of Science Equality Commissions. Improved global stakeholder involvement can increase research impacts and help fight inequalities. In all investigated topics we see promising beginnings but also recognize obstacles that include a lack of funding, a lack of understanding of diversity, and prioritizing short‐term gain over long‐term benefit. Nonetheless, we are hopeful that our community will embrace ICON science.
Human activity has been fundamental in shaping the natural landscapes of Sierra NevadaSierra Nevada. This chapter offers an overview of the evolution of the occupation of this mountain range and of the changes in the ways of managing and exploiting its resources. The study spans the still poorly known Metal Ages and Roman period to medieval times, a period characterized by a great transformation that marked Sierra NevadaSierra Nevadacultural landscapeCultural landscape due in large part to the introduction of irrigation systemsIrrigation Systems and a complex socio-ecosystem that conditioned most economic activities. The current analysis also delves into the changes provoked by the Castilian conquest, the arrival of the new settlers, and the later Industrial Revolution and application of liberal policies. The irrigation systemsIrrigation Systems reveal a great resilienceResilience, surviving even today and playing a key role in Sierra NevadaSierra Nevada ecosystems and landscapes.
The early Miocene La Rinconada mine from eastern Iberian Peninsula contains a rich megafloral assemblage with abundant leaf fossils from a single stratigraphic level of the sedimentary succession. This has provided a good opportunity to undertake detailed comparative quantitative palaeoclimate reconstruction using different approaches, namely the Coexistence Approach (CA), Climate Leaf Analysis Multivariate Programme (CLAMP) and Leaf Margin Analysis (LMA). Considering the results of all techniques used, the palaeoclimate estimates are the following: mean annual temperature (MAT) CA = 10–16.5 °C/CLAMP = 11.48 °C, warmest month mean temperature (WMMT) CA = 25–26.4 °C/CLAMP = 23.31 °C, coldest month mean temperature (CMMT) CA = 4.3–4.8 °C/CLAMP = 0.84 °C, mean annual precipitation (MAP) CA = 1217–1297 mm, mean precipitation of the wettest month (MPWet) CA = 116–164 mm and mean precipitation of the warmest month (MPWarm) CA = 118–131 mm. Temperature and precipitation values obtained through CLAMP, LMA and CA indicate the occurrence of a wet and warm climate the whole year around with marked seasonality for rainfall and temperature but without a summer-dry regime. The climatic values obtained in the La Rinconada mine are in well accordance with other Burdigalian and late Burdigalian–early Langhian sites from the Iberian Peninsula (e.g. S 141 Borehole) and Central-Southern Europe (e.g. Holedeč, Čermníky, Přívlaky, Bílina Delta, Manisa-Soma, Spanokhorion and the Evia Island), suggesting the absence of a clear latitudinal gradient in temperature and precipitation for this period in Europe. This climate is consistent with the plant communities described in the area from taxonomic studies and IPR analysis.
The Gulf of Cadiz and the Alboran Sea are characterized by tectonic activity due to oblique convergence at the boundary between the Eurasian and Nubian plates. This activity has favored a variety of tsunamigenic sources: basically, seismogenic faults and submarine landslides. The main tsunamigenic faults in the Gulf of Cadiz would comprise the thrust systems of Gorringe Ridge, Marquês de Pombal, São Vicente Canyon, and Horseshoe faults with a high susceptibility; meanwhile in the Alboran Sea would be the thrust system of the northern Alboran Ridge with high susceptibility, and the thrust systems of north Xauen and Adra margin, the transpressive segment of Al Idrissi fault, and the Yusuf-Habibas and Averroes faults, with moderate to high susceptibility. The areas with the greatest potential to generate tsunamigenic submarine landslides are in the Gulf of Cadiz, the São Vicente Canyon, Hirondelle Seamount, and Gorringe Ridge; and in the Alboran Sea are the southern and northern flanks of Alboran Ridge. Both sources are likely to generate destructive tsunamis in the Gulf of Cadiz, given its history of bigger earthquakes (>7 Mw) and larger landslides. To fully assess tsunamigenic sources, further work needs to be performed. In the case of seismogenic faults, research focus on geometry, offsets, timing, paleoearthquakes, and recurrence, and in landslides on early post-failure evolution, age, events, and recurrence. In situ measurements, paleotsunami records, and long-term monitoring, in addition to major modeling developments, will be also necessary.
Geologic gas storage is a sustainable strategy to store energy in underground reservoirs in order to be used under demand. Injection and withdrawal gas operations could trigger induced seismicity according to the tectonic constrains of the reservoir. The study of the active stress/strain fields shows the properties of the fault patterns that can be involved in induced seismicity. In our work, we have determined the strain/stress field in the Yela underground gas storage, an Upper Cretaceous carbonate reservoir located in central Spain. Slickensides on fault planes were measured from Cretaceous, Miocene and Quaternary rocks. Results show a strain field with ey (maximum horizontal shortening) oriented NW-SE. This field was compressional during the early Miocene, switching off to extensional from late Miocene to present-day. Our results suggest that NNW-SSE and NW-SE oriented faults could act as an effective pathway for gas leakage and prone to trigger induced seismicity. Moreover, 141 small earthquakes (Mmax 2.3) were recorded during underground operations in Yela. Peaks of earthquakes appear seasonally from November to February, in coincidence with the injection operations prior to the winter withdrawal. Working at its maximum gas storage volume, earthquake peaks decreased in intensity and magnitude from 2017 to 2021, and show a time lag of 3 months from the month of maximum volume injection to the earthquake occurrence.
Braconid parasitoid wasps are a widely diversified group today, while their fossil record from the Mesozoic is currently poorly known. Here, we describe Utrillabracon electropteron Álvarez-Parra & Engel, gen. et sp. nov. , from the upper Albian (Lower Cretaceous) amber of San Just in the eastern Iberian Peninsula. The holotype specimen is incomplete, although the forewing and hind wing venation are well preserved. The new taxon is assigned to the subfamily †Protorhyssalinae (Braconidae) and, based on characteristics of the wing venation, seems to be closely related to Protorhyssalus goldmani Basibuyuk & Quicke, 1999 and Diorhyssalus allani (Brues, 1937), both from Upper Cretaceous ambers of North America. We discuss the taxonomy of the Cretaceous braconids, considering †Seneciobraconinae as a valid subfamily. We also comment on possible relationships within †Protorhyssalinae, although a phylogenetic analysis is necessary. Additionally, a checklist is included of braconids known from Cretaceous ambers.
Recent studies highlight the fragility of the Mediterranean basin against climate stresses and the difficulties of managing the sustainable development of groundwater resources. In this work, the main issues related to groundwater management have been identified from the stakeholder’s perspective in the following four representative water-stressed Mediterranean areas: the coastal aquifer of Comacchio (Italy), the Alto Guadalentín aquifer (Spain), the alluvial aquifer of the Gediz River basin (Turkey), and the Azraq aquifer (Azraq Wetland Reserve, Jordan). This has been achieved by designing a methodology to involve and engage a representative set of stakeholders, including a questionnaire to learn their point of view concerning the current management of aquifer systems and their experience with the already available tools for groundwater resource management, such as monitoring networks and numerical models. The outcome of the survey has allowed us to identify both particular and common challenges among the four study sites and among the various groups of stakeholders. This information provides valuable insights to improve the transfer of scientific knowledge from the research centers to the authorities managing the groundwater resources and it will help to plan more effective research activities on aquifer management. The proposed methodology could be applied in other aquifers facing similar problems.
The Gulf of Cadiz Contourite Depositional System (GCCS) developed due to the interaction of the Mediterranean Outflow Water (MOW) with the middle continental slope of the SW Iberian continental margin. The GCCS evolved in a complex tectonic setting within the foreland of the Betic Orogeny and near the Nubia-Eurasia plate boundary. This study used tectonostratigraphic analysis of an extensive 2D multichannel seismic reflection dataset to investigate how inherited basin configuration and tectonic activity controlled sedimentary stacking pattern and evolution of the GCCS. The GCCS includes three regional tectonostratigraphic units (U1-U3). The younger seismic unit U3 corresponds to the Miocene-Quaternary foreland basin system where the contourite system is generated. Seismic analysis also detected the dextral strike-slip Gil Eanes Fault Zone (described herein for the first time), the Cadiz Fault, the Albufeira-Guadalquivir-Doñana Basement High and several diapiric structures. Integrated analysis of seismic profiles showing these tectonic structures with thickness and earthquake distribution maps suggest four tectono-sedimentary domains. The distinct characteristics shown by contourite features in the different domains, depends at broad-scale on the tectonic-control of the accommodation space (i.e., subsidence or uplift) and at local-scale on the presence of structural highs and fault-related depressions. Both influence bottom-current circulation and thus the evolution of the contourite deposits through the late Miocene and Quaternary. Three main stages have been recognised in the Gulf of Cadiz evolution: 1) the region was the western continuation of the Betic Corridor until the final re-opening of the Strait of Gibraltar (8–5.3 Ma). In this stage there is a predominance of turbidites or hemipelagic deposits, dependant on tectonic activity; 2) with the final re-opening of the Mediterranean-Atlantic connection there is the onset of the Pliocene- Quaternary contourite depositional system (5.3–2.0 Ma). Short-term changes in sedimentation during this stage, from contourite to turbidite deposits, indicate periods of increased tectonic activity; and 3) after the onset of the transpressive tectonic regime in the area (from 2.0 Ma), sedimentation became more homogeneous suggesting stable conditions (decrease of tectonic activity) with dominant contourite deposition. This work highlights the remarkable influence of structural features and tectonic events in controlling the seafloor relief and in turn in influenced the local oceanic circulation processes that controlling the morphology and sedimentary evolution of contourite systems.
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