Lousal mine is a typical “abandoned mine” with all sorts of problems as consequence of the cessation of the mining activity and lack of infrastructure maintenance. The mine is closed at present, but ...the heavy metal enriched tailings remain at the surface in oxidizing conditions. Surface water and stream sediments revealed much higher concentrations than the local geochemical background values, which the “Contaminated Sediment Standing Team” classifies as very toxic. High concentrations of Cu, Pb, Zn, As, Cd and Hg occurred within the stream sediments downstream of the tailings sites (up to: 817
mg
kg
−1 As, 6.7
mg
kg
−1 Cd, 1568
mg
kg
−1 Cu, 1059
mg
kg
−1 Pb, 82.4
mg
kg
−1 Sb, 4373
mg
kg
−1 Zn). The AMD waters showed values of pH ranging from 1.9 to 2.9 and concentrations of 9249 to 20,700
mg
L
−1 SO
4
−2, 959 to 4830
mg
L
−1 Fe and 136 to 624
mg
L
−1 Al. Meanwhile, the acid effluents and mixed stream waters also carried high contents of SO
4
2−, Fe, Al, Cu, Pb, Zn, Cd, and As, generally exceeding the Fresh Water Aquatic Life Acute Criteria. Negative impacts in the diatom communities growing at different sites along a strong metal pollution gradient were shown through Canonical Correspondence Analysis: in the sites influenced by Acid Mine Drainage (AMD), the dominant taxon was
Achnanthidium minutissimum. However,
Pinnularia acoricola was the dominant species when the environmental conditions were extremely adverse: very low pH and high metal concentrations (sites 2 and 3). Teratological forms of
Achnanthidium minutissimum (Kützing) Czarnecki,
Brachysira vitrea (Grunow) Ross in Hartley,
Fragilaria rumpens (Kützing) G. W. F. Carlson and
Nitzschia hantzschiana Rabenhorst were found. A morphometric study of
B. vitrea showed that a decrease in size was evident at the most contaminated sites. These results are evidence of metal and acidic pollution.
► We have performed the geochemical characterization of the Lousal area. ► We evaluate the extent of pollution in sediments and stream waters and related toxicity. ► We investigate the geochemical characteristics of the AMD discharged from the abandoned mine adits and tailing piles. ► We compare the diatom communities along a strong metal pollution gradient. ► We evidence the presence of teratological forms and the decrease in individual cell size due to metal pollution and low pH.
The Neves-Corvo world class Iberian Pyrite Belt volcanogenic massive sulphide (VMS) deposit located in southern Portugal, constitutes an important Cu–Zn–Pb active mine
.
Seven deposits are currently ...known, among which the Lombador deposit alone has estimated 150 Mt of massive sulphides. The life-time of the mine is dependent on the discovery of new exploration targets and it is vital to have accurate 3D geological models, not only to guide drilling campaigns but also to drive a winning/new strategy, which in the past has led to Semblana and Monte Branco discoveries: geophysical inversion and modelling. Furthermore, 3D geological models can contribute to the understanding of the tectonic and stratigraphic evolution of the region. Therefore, the goal of this study is to produce a realistic 3D geological model of the Neves-Corvo region, as only one model is presently publicly available: the PROMINE model, which includes the study area of this work and extends from Aljustrel to the border with Spain. Lundin Mining has also produced two unpublished, confidential models in 2007 and 2017. The latest Lundin model incorporates the same geophysical data used in this work (2D and 3D seismic reflection and time-domain electromagnetic (TEM) ground loop data) and approximately 7500 surface and underground drill-holes. The model presented in this research has much more detail than the 2012 PROMINE model in the Neves-Corvo region and uses an updated and revised drill-hole database with approximately 8000 drill-holes, revised geological cross-sections built from surface geology and drill-hole logs, new geological outcrop data, petrophysical and reprocessed geophysical data, and is therefore more detailed and accurate than any of the previous models, in particular the 2007 and PROMINE models. Land gravimetric and aeromagnetic data are also available in the study area but were not directly used to build the geological model but rather to investigate and check the model produced. Modelling was performed with industry standard software and the 3D curves resulting from the geological/geophysical interpretation were interpolated using different approaches to respect the hard data (interpretation lines and drill-holes). The resulting 3D stratigraphic surfaces required strong manual editing to respect the interpretation, due to the presence of folds, thrusts and tectonic nappes in the study area. The surfaces were afterwards tied to the drill-holes, resulting in a 3D model with great accuracy and detail in the near mining area and covering a larger area than previously available 3D geological models. The model has three major stratigraphic layers: the Mértola Flysch Formation and the Volcano-Sedimentary Complex (VSC), overlying the Phyllite-Quartzite Formation basement, and also the known VMS deposits (underlying the top of the Lower VSC) geometries according to drill-hole data. In the central part of the study area, where more drill-holes are available, the top of the Lower VSC sequence surface was also built. This approach will contribute to a better exploration drill-hole planning and the generation of new targets for exploration.
The flavonoid Galetin 3,6-dimethyl ether (
1) and the fractions obtained from aerial parts of
Piptadenia stipulacea presented antinociceptive and anti-inflammatory actions in pain models. The results ...demonstrated in the present study support, at least in part, the ethnomedicinal uses of this plant.
In this study, we attempted to identify the possible antinociceptive and anti-inflammatory actions of the aqueous phase, the ethyl acetate phase and one unknown flavonoid obtained from aerial parts of
Piptadenia stipulacea, known in Brazil as “jurema-branca”, “carcará” and “rasga-beiço”.
Aerial parts of
Piptadenia stipulacea were used and after fractionation, the flavonoid FGAL was obtained. Experiments were conducted on Swiss mice using the acetic acid-induced writhing test, the hot plate test, the formalin-induced pain test and zymosan A-induced peritonitis test.
The aqueous and ethyl acetate phases (p.o., 100
mg/kg); and the flavonoid FGAL (p.o. and i.p. at 100
μmol/kg), reduced the nociception produced by acetic acid, by 49.92%, 54.62%, 38.97% and 64.79%, respectively.
In vivo inhibition of nociception by the ethyl acetate phase (100
mg/kg, p.o.) in the hot plate test was favorable, indicating that this fraction exhibited central activity. The ethyl acetate phase (100
mg/kg, p.o.) reduced the formalin effects in both phases by 28.51% and 55.72%, respectively. Treatment with the aqueous phase (100
mg/kg, p.o.) and FGAL (100
μmol/kg, i.p.) only protected the second phase by 69.76% and 68.78%, respectively. In addition, it was observed in the zymosan A-induced peritonitis test that the aqueous phase, the ethyl acetate phase and the FGAL exhibited anti-inflammatory activity, reducing significantly the number of recruit cells by 35.84%, 37.70% and FGAL (
1), respectively.
These data demonstrate that the FGAL elicits pronounced antinociceptive activity against several pain models. The actions of this flavonoid probably are due to antioxidative properties. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for this antinociceptive action and also to identify other active substances present in
Piptadenia stipulacea.
Heavy-metal contamination of Pinus pinaster, P. sylvestris, Quercus robur, and Q. rotundifolium was studied in four abandoned historic Cu deposits from Italy (Libiola, Caporciano), Portugal (São ...Domingos), and Slovakia (L'ubietová). The highest Cu and Mn contents in anthropogenic soil were described in Libiola and Caporciano whereas the highest Pb, Zn, As, and Sb contents in São Domingos. The anthropogenic soil in L'ubietová shows the highest Co contents. The area of São Domingos is the most acidified. There are important differences between the bioaccumulation of plants from individual deposits. Bioavailability of the heavy metals is generally independent of the pH values. The high Ca and Mg contents in soil are able to block the transport of heavy metals to the plant tissues. The bioconcentration factor values of all plant taxa, in all deposits, indicate a predominant strategy of excluders. Only Ag shows excellent bioconcentration ability. In L'ubietová, Pinus sylvestris has a strategy as an accumulator of Pb (2.43) and Zn (2.49); Pinus pinaster of Mn (4.97), Cd (1.85), and Co (5.62) and Quercus rotundifolium of Mn (3.54) in São Domingos. The predominantly low translocation factor values indicate that in most cases the heavy metals are accumulated in roots; only in a few rare cases do they migrate to shoots (e.g. Zn in Pinus sp. from all localities, Co in P. pinaster in São Domingos).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
This study investigates the leishmanicidal activity of five species of plants used in folk medicine in endemic areas of the state of Alagoas, Brazil. Data were collected in the cities of Colonia ...Leopoldina, Novo Lino, and União dos Palmares, Alagoas state, from patients with cutaneous leishmaniasis (Leishmania amazonensis) who use medicinal plants to treat this disease. Plants extracts were tested at a concentration of 1–100 μg/mL in all experiments, except in an assay to evaluate activity against amastigotes, when 10 μg/mL was used. All plants extracts did not show deleterious activity to the host cell evidenced by LDH assay at 100, 10, and 1 μg/mL after 48 h of incubation. The plants extracts Hyptis pectinata (L.) Poit, Aloe vera L., Ruta graveolens L., Pfaffia glomerata (Spreng.) Pedersen, and Chenopodium ambrosioides L. exhibited direct activity against extracellular forms at 100 μg/mL; these extracts inhibited growth by 81.9%, 82.9%, 74.4%, 88.7%, and 87.4%, respectively, when compared with promastigotes. The plants extracts H. pectinata, A. vera, and R. graveolens also significantly diminished the number of amastigotes at 10 μg/mL, inhibiting growth by 85.0%, 40.4%, 94.2%, and 97.4%, respectively, when compared with control. Based on these data, we conclude that the five plants exhibited considerable leishmanicidal activity.
To evaluate the accumulation of trace elements (TE) by vegetables produced in the vicinity of abandoned pyrite mines, eighteen different small farms were selected near three mines from the Portuguese ...sector of the Iberian Pyrite Belt (São Domingos, Aljustrel and Lousal). Total and bioavailable As, Cu, Pb, and Zn concentrations were analyzed in the soils, and the same TE were analyzed in three different vegetables, lettuce (Lactuca sativa), coriander (Coriandrum sativum), and cabbage (Brassica oleracea), collected at the same locations. The soils were contaminated with As, Cu, Pb, and Zn, since their total concentrations exceeded the considered soil quality guideline values for plant production in the majority of the sampling sites. The maximum total concentrations for those TE were extremely high in some of the sampling sites (e.g. 1851mgAskg−1 in São Domingos, 1126mgCukg−1 in Aljustrel, 4946mgPbkg−1 in São Domingos, and 1224mgZnkg−1 in Aljustrel). However, the soils were mainly circumneutral, a factor that contributes to their low bioavailable fractions. As a result, generally, the plants contained levels of these elements characteristic of uncontaminated plants, and accumulation factors for all elements <1, typical of excluder plants. Furthermore, the estimated daily intake (EDI) for Cu and Zn, through the consumption of these vegetables, falls below the recommended upper limit for daily intake of these elements. The sampling site that stood out from the others was located at São João de Negrilhos (Aljustrel), where bioavailable Zn levels were higher, a consequence of the slight acidity of the soil. Therefore, the Zn content in vegetables was also higher, characteristic of contaminated plants, emphasizing the risk of Zn entering the human food chain via the consumption of crops produced on those soils.
•Soils in kitchen gardens near pyrite mines are heavily contaminated with As, Cu, Pb, and Zn.•Soil is mainly neutral, due to soil amendment, which contributes to the low bioavailability of TE.•Generally, vegetables contain levels of these elements characteristic of uncontaminated plants.•Risk is considerable where the soil pH is acidic, triggering high Zn bioavailable concentrations.•If the soil pH is not controlled, there is a risk of consuming metal contaminated vegetables.
In the last 20 years in Portugal, water resources have been affected to the point that water storage has decreased by 20% since 2000. Creating strategies to manage water resources requires a ...comprehensive understanding of the factors influencing water storage and their effects over time. This study is focused on the evolution of Groundwater Deep Levels (GDL) by applying a two-phase trend analysis methodology to examine the dynamic changes in GDL within a series of monitoring wells located in the Central and Southern sectors of the Left Bank of the Tagus-Sado Cenozoic age Basin, situated in Portugal In the initial phase of trend analysis, Factorial Analysis of Mixed Data (FAMD) was employed and posteriorly the Hierarchical Classification Analysis (HCA). These techniques enabled us to identify distinct GDL trend profiles and generate interpretative maps illustrating their spatial distribution
.
In the second phase, the non-parametric Mann–Kendall Analysis (MKA) and Innovative Trend Analysis (ITA) were applied, allowing for a quantified confirmation of the different trend profiles previously detected. These techniques allowed the identification of positive and negative hydrodynamic trends in distinct sections of the Basin. In the SE sector they are characterized by a significative increase of GDL associated with overexploitation and in the Central sector with a decrease of GDL. Nevertheless, significant depletion effects can result from natural factors such as prolonged droughts, and in certain regions, changes in geological and hydrothermal dynamics, such as Alpine-age faults, graben, and horst structures, may account for these alterations.
Located in the Iberian pyrite belt, the Neves–Corvo mine is a world-class massive sulfide deposit and the largest operating mine in Portugal with underground mining down to 1000 m depth focused on ...massive and stockwork Cu, Zn, Pb rich ores. Gravimetric data have had a leading role in the discovery of the seven known deposits, together with time-domain electromagnetic (TEM) ground data. In this work, we present the results of a 3D constrained gravity inversion carried out with legacy ground gravity data. The 3D gravity inversions were carried out using an updated density database containing approximately 142,000 measurements. A recently constructed 3D geological model based on reprocessed 2D seismic reflection, 3D seismic, TEM and updated geology from detailed surface mapping and drill-hole data, was used to constrain the inversions. The results show multiple high-density anomalies that may indicate the presence of mineralization at depth. These anomalies were therefore cross-checked with holes previously drilled. Approximately 97% of more than 1000 available surface drill-holes located on or at a distance of less than 200 m from the high-density anomalies intersected mineralization. However, gravity anomalies have been drilled in the past and particularly dense black shales or rhyolitic/gabbroic rocks have been intersected. To increase the success of future drilling, gravimetric anomalies have been correlated spatially with high-conductivity TEM zones and strong-amplitude seismic reflections, because igneous rocks usually present weak-to-moderate conductivity and a massive column of black shales presents a seismic signature quite different from that of mineralization. We concluded that some of these locations represent high-quality targets to consider following up with drilling and further exploration.
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