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Este artigo deriva de uma comunicação apresentada em International workshop “Uranium, Environment and Public Health”, UrEnv 2013.

The distribution patterns of trace elements are very useful for predicting mineral deposits occurrence. Machine learning techniques were used for the computation of adequate models in trace elements’ prediction. The main subject of this research is the definition of an adequate model to predict the amounts of Sn and W in the abandoned mine area of Lardosa (Central Portugal). Stream sediment samples (333) were collected within the study area and their geochemical composition - As, B, Be, Cd, Co, Cr, Cu, Fe, Ni, P, Sn, U, V, W, Y, and Zn - used as input attributes. Different machine learning techniques were tested: Decision Trees (CART), Multilayer Perceptron (MLP) and Support Vector Machines (SVM). For regression and clustering, CART, MLP approaches were tested and for the classification, problem SVM was used. These algorithms used six different inputs – N1 to N6 – aiming to pick out the best-performing model.The results show that CART is the optimized predictor for Sn and W. Concerning the regression approach, correlation coefficients of 0.67 for Sn (with Input N1) and 0.70 for W (with Input N3) were obtained. Regarding the classification problem, an error rate of 0.10 was reached for both Sn (Input N1) and W (Input N2). The classification process is the best methodology to predict Sn and W, using as input the trace element concentrations in the collected stream sediment samples, Lardosa area, Portugal.

Thermal mineral waters are a potential resource in the local and economic development of a region. The thermal area of Termas das Águas is in the inner region of central Portugal and its grant will enable the exploration and exploitation of this water resource for medical and therapeutic purposes through a thermal medical SPA. In Portugal, the classification and legalization of a thermal unit must provide a natural mineral water resource, recognized by Portuguese Energy and Geology General Directorate and integrated in a concession granted by the Portuguese Government. For this purpose, it will be necessary to have available mineral water, with physico-chemical and microbiological, temporal stability, ensuring water’s high quality. The purpose of a certified mineral water includes a detailed geomorphological, geological and hydrogeological characterization of the survey area, as well as the water's compositional temporal stability. Only after the recognition conferred by the national agency as a natural mineral water, it is possible to start a medical-hydrological study, for this resource. This process follows an experimental period of 3 years, during which it is implemented the different and specific balneotherapy techniques associated with the therapeutic features of the mineral water. A final report, to be submitted to Portuguese General Directorate for Health, will gather the main results and conclusions, regarding the benefits of this natural resource on human health, and allow its inclusion as an official medical thermal SPA in the Portuguese Normative Decrees. The main subject of this research is the geological and hydrogeological characterization of Termas das Águas aquifer, as well as the mineral water quality study (AM4 – well). The main topics for the medical hydrological study, mainly related to rheumatic and respiratory diseases, are also presented to the medical SPA of Termas das Águas.

Surface water is exposed to contaminants which change the natural hydrological parameters and consequent contaminant dispersion. Water self-depuration is an ecological process aiming to restore the natural watercourse balance, which depends on the quality and quantity of topical and diffuse contributions. The main goal of this research is the evaluation of surface water quality in the Águeda River (Portugal-Spain transboundary watershed) and its self-depuration ability considering different predicted scenarios. Biochemical oxygen demand (BOD5), dissolved oxygen (DO), dry residue, Ptotal, Ntotal, pH, temperature and microbiological parameters were analyzed, in thirty-six surface water samples. Simulation of different quality scenarios was undertaken using Qual2Kw software and the river's self-depuration ability discussed. The obtained model's calibration achieved a score of 95% confidence interval, for almost analyzed parameters. The calibrated model was used for two prediction scenario construction. The first one, intending to assess the influence of topical contaminated discharge and the second one, aiming to evaluate the influence of minimum flow rates, representing an extremely dry year. The two considered scenarios revealed that self-depuration capacity is more affected by the presence of minimum flow rates than topical discharges, attesting a large potential for self-depuration along the Águeda River.

Pollution from mining activities is a significant problem in various regions of the Republic of Macedonia. A geochemical survey of the surface deposits of Lake Kalimanci in the easterly region of the Republic of Macedonia was carried out before (2001) and later (2007) the dam failure and thus allowing the measurement of the tailings’ material from Sasa Pb-Zn Mine-Osogovo Mountains (Eastern Macedonia). The concentrations of potentially toxic elements (PTE): Ag, Au, Cd, Co, Cu, Pb, Sb, Th, S, U and Zn were obtained by ICP Mass Spectrometry (ACME Laboratories in Vancouver, Canada). Data analysis, through Principal Component Analysis (PCA), was performed in order reduce the space of analyses by the construction of synthesis variables (Principal Factors). Geostatistical modeling was used, throughout conventional variography and the Sequential Gaussian Simulation algorithm (SGS), to model the new factors' spatial distribution. A hundred simulations, differing in their initial random-number seed, were performed and a Mean Image (MI) obtained. Spatial uncertainty evaluation (simulation’s Standard Deviation) allowed the definition of future monitoring and sampling strategies as well as the measurement of remediation possibilities.

The abandoned Alto da Várzea radium mine exploited quartz veins containing ore minerals and U-bearing minerals, such as autunite and torbernite. The area is located on a Variscan two-mica granite that intruded the schist–greywacke complex. The mine was exploited underground from 1911-22 and was closed down in 1946. This mine was not restored and actually a commercial area is deployed.A total of ten surface water and groundwater samples were collected in the study area between 2008/09. Most water samples have pH values ranging from 4.3 to 6.8 and are poorly mineralized (EC=41-186 μ S/cm; TDS=33-172 mg/L). However, the waters are contaminated with NO2-, Mn, Cu, As and U and must not be used for human consumption and some of them in agricultural activities. The water contamination is mainly associated with the old radium mine and human activities developed in the area.

Neste trabalho são propostos os padrões de distribuição espacial para contaminantes em águas subterrâneas – Urânio e Arsénio, na bacia transfronteiriça do rio Águeda. Os mapas obtidos permitem avaliar o risco ambiental associado às atividades antrópicas desenvolvidas na área em estudo, constituindo as atividades mineiras um importante fator de risco ambiental. Pretende-se, ainda, contribuir para uma melhoria na gestão dos sistemas de águas e possibilitar a futura definição de políticas de atuação conjunta, em casos transfronteiriços, tal como é apresentado neste trabalho.

Uranium and thorium are toxic in different environments. The exploitation of uranium mines and associated mine drainage leaching towards streams, sediments, and soils cause relevant pollution. The U-mine areas present high concentrations of potentially toxic elements with several consequences to ecosystems and human health. Physicochemical and potentially toxic elements of mine dumps, stream sediments, and soils from the Canto Lagar uranium mine area (Central Portugal) were analyzed. Stream sediments, soils, and mine dumps show a large range in the concentration values of Fe, U, As, Cu, Zn, Pb, and Th, suggesting geological and mine contributions. Most of the selected potential toxic elements from sediments present a low to moderate contamination degree, except for As, W, and U, which vary between high and very high contamination index. The soils must not be used in agricultural or residential activities due to contamination in As and U. This abandoned mine represents an environmental risk due to the spatial mobility and dispersion of potentially toxic elements from the dumps to the sediments and soils, as well as by surface runoff and wind.

Groundwater vulnerability assessment has become a useful tool for groundwater pollution prevention. Groundwater vulnerability maps provide useful data for protecting groundwater resources. Identification of agricultural patterns is an important issue for optimized land management. The watershed of the Tagus River is the backbone of this study. Naturtejo UNESCO Global Geopark, in the central interior of Portugal, corresponds to a rural area. Intensive agricultural practices showed an increasing trend in the last decades. The method that is most used internationally to assess vulnerability is the DRASTIC index. In this study, the DRASTICAI index is introduced. A new attribute—anthropogenic influence—is added here. Five levels of increasing vulnerability, from low to high, can be recognized here. The municipality of Idanha-a-Nova is most affected by intensive agricultural activities, showing spatial patterns of DRASTICAI with a clear influence of anthropogenic activities, with high needs for groundwater abstraction. A robust assessment of groundwater quality has a key role. Climate change scenarios and water scarcity are important issues in the coming years, and particularly in the studied area. Therefore, optimized groundwater management is essential to consider in policy-making strategies.

Nowadays, groundwater vulnerability assessment has become a useful tool for groundwater contamination prevention. Groundwater vul-nerability maps provide useful data to protect groundwater resources and work as a tool for the improvement of changes in agricultural patterns and land use applications. The study area of this research survey is the Naturtejo UNESCO Global Geopark, located in central inland Portugal and corresponding to a mainly rural territory where intensive agricultural practices showed a rising tendency in the last decades. The most used method of vulnerability evaluation is the DRASTIC index. In this survey, a modified DRASTIC method, DRASTICAI, is introduced. A new attrib-ute designated as Anthropogenic Influence is introduced. Map algebra in a GIS environment allowed the computation of the two maps by overlaying the needed attributes. The Vila-Velha-de Rodão and Idanha-a-Nova mu-nicipalities show moderate to high vulnerability and, therefore, in need of monitoring, since intensive agricultural practices are the main economic activity. The algebraic subtraction of DRASTIC and DRASTICAI maps revealed a considerable increase in the risk of contamination, over the sur-veyed area, namely in Idanha-a-Nova where it is observed risk increase up to 45 points, changing from moderately vulnerable to highly vulnerable and, therefore, stressing the importance of anthropogenic activities.

A biotite granodiorite and seven Sn-bearing two-mica granites crop out in the Gouveia area, central Portugal. A SHRIMP U–Th–Pb zircon age from the granodiorite, and monazite ages from four of the two-mica granites, show that they are of Early Ordovician (~480 Ma) and Permo-Carboniferous, i.e. Variscan (~305 and 290 Ma) age respectively. The Variscan two-mica granites are late- and post-D3. Major and trace element variation in the granitic rocks and their biotite and muscovite indicate mainly individual fractionation trends. The granitic rocks are mostly depleted in HREE relative to LREE. The biotite granodiorite is probably derived from igneous lower crust, as evidenced by low initial 87Sr/86Sr (0.7036), high εNdT (+2.5) and moderate δ18O (8.8‰). The two-mica granites are probably derived by partial melting of heterogeneous mid-crustal metasediments, mainly metapelite and some metagraywacke, as evidenced by their high initial 87Sr/86Sr (0.7076–0.7174), δ18O (10.7–13.4‰) and major element compositions. However, variation diagrams for major and trace elements from two of the muscoviteNbiotite granites and their micas define fractionation trends. Rb–Sr whole-rock analyses from the two granites are perfectly fitted to a single isochron and the rocks have subparallel REE patterns; the younger granite is derived from the older by fractional crystallization of quartz, plagioclase, biotite and ilmenite (tested by modelling major and trace elements). Most of the Sn-bearing granites are derived from distinct magma batches. They result from partial melting of a heterogeneous midcrustal metasediment. They do not represent a crustal anomaly in tin. Fractional crystallization is responsible for the increase in the Sn contents of the granites and their micas. Muscovite has a higher Sn content than coexisting biotite and is the principal host mineral for Sn in these rocks.

Beekeeping offers a great development potential, as a source of food, as a nutritional complement and also as raw material provider to several activities. Moreover, biodiversity improvement conservation, incentive for retention of natural habitats and an ideal activity for forest conservation programmes are important factors associated with this activity. Honey is a natural sweet product that is produced in almost all Portuguese Regions. Honeys from certain areas are preferred mainly because of their sensory characteristics, which are related to their floral origin. The pollen and nectar variability influences the honey flavour and determines its commercial quality. The aims of this work are: geographical identification of existing apiaries in the central region of Portugal; identification and quantification of floral sources; characterization of honey (sensory and physico-chemical); construction of thematic maps supporting the new hives installation, predicting the honey characteristics. This methodology has been applied in a Portuguese studied area (Vila Velha de Ródão). A first identification of the apiaries allowed the establishment of the potential zones to future beekeepers installation (Lidónio et al., 2009) (Figure 1). In order to complete the previous information, it is in progress the identification and quantification of species for apiculture interest as well as the honey physical and chemical characterization. Potential apiculture development characterization has been mapped using the following attributes: surrounding area for 200 vegetation units (Forestry zones, agricultural zones and bush zones); slopes warm temperate (warm and very hot); the surrounding area, about 200m, around the water lines and water points; surrounding feeding apiary area (50m diameter); urban admissible legal boundary (100 m diameter for each apiary). It was also considered, the shading maps because of its importance on hive production and bee behaviour. Shading values considered favourable are between 0 and 127. A methodological procedure was developed, aiming the potential beekeeping map construction. Identification of favourable areas, for future beekeepers apiaries installation, will be possible in result of this study. In many Portuguese regions some beekeepers transport their hives, according to the floral sources development in order to reach regions where the production of some species is higher, allowing the improvement of some crop pollinization, for a specific month. Vila Velha de Rodão area, about 10885ha, presents excellent conditions for proper development of beekeeping. It is well documented that the pollen quality and variability, influences the honey flavour and quality (Anjos et al., 2009). The studied region is limited by the major watercourses and their respective valleys and steep slopes. Predominantly those uncultivated land, presents high biodiversity with high beekeeping potential. Some of the most important species present in this region are, Lavandula pedunculata (Miller) Cav., Cistus ladanifer L., Rosmarinus officinalis L., Erica umbellata L., Erica 13th AGILE International Conference on Geographic Information Science 2010 Page 2 of 3 Guimarães, Portugal australis L., Erica lusitanica, Calluna vulgaris (L.) Hull, Retama sphaerocarpa (L.) Boiss., Echium plantagineum L., Genista triacanthos Brot., Quercus rotundifolia Lam, Quercus pyrenaica Willd., Cytisus multiflorus (L'Hér.) Sweet and Cytisus striatus (Hill) Rothm, Arbutus unedo L., Eucalyptus globulus Labill. and Juniperus oxycedrus L. (Almeida, 2004; Carvalhinho, 2004; Monteiro, 2003). In future works, iso-quality mapping, for beekeeping potential characterization, will be concluded, for central Portugal. This will allow the beekeepers installation optimization and support a honey production sustainable management.

O impacte de descargas de ETAR, na qualidade da água, deve ser monitorizado e controlado. Este trabalho centra-se no rio Ocreza, apresentando um exemplo do impacte devido às descargas de uma ETAR num dos seus afluentes. As amostras foram colhidas entre a descarga da ETAR e a sua confluência com o rio Ocreza. As amostras, aproximadamente equidistantes, foram localizadas e georreferenciadas a jusante de contribuições secundárias. Três campanhas foram realizadas durante o ano hidrológico de 2010: inverno chuvoso (janeiro), condições intermediárias (março) e verão seco (junho). Para todas as campanhas e os pontos amostrados, foi estimado o caudal e analisados os parâmetros químicos seguintes: carência bioquímica de oxigénio aos cinco dias (CBO5), oxigénio dissolvido (OD), resíduo seco, Ptotal, Ntotal, pH, temperatura e parâmetros microbiológicos. Um modelo de dispersão hidrodinâmico foi usado para simular a poluição no rio Ocreza, devido à descarga de efluentes. O software QUAL2kw (Pelletier et al, 2006) foi usado para construir um modelo de qualidade da água. Os resultados das simulações são consistentes com as observações de campo e demonstram que o modelo foi calibrado corretamente, permitindo, deste modo, estudos de viabilidade de diferentes esquemas de tratamento e desenvolvimento de actividades de monitorização específicas.

O estudo de caracterização do impacte ambiental, provocado pelas descargas das ETARs, foi direccionado aos afluentes: Ribeira da Líria, ribeira da Freixada e rio Ramalhoso.

Teledetección e fotointerpretación para el estudio de la evolución de la cuenca del rio Águeda.

Cohesión cartográfica en proyectos transfronterizos. El proyecto Agueda.

Resumen: En este trabajo se presenta el balance hídrico de una masa de agua subterránea de naturaleza kárstica de la cuenca sedimentaria del Duero, centro oeste de España. Los datos obtenidos para la realización del balance han sido introducidos en una herramienta de simulación con el fin de conocer la evolución temporal de los recursos hídricos a lo largo del año hidrológico. Para ello se ha sido necesario recurrir a la utilización de técnicas geostadísticas y el programa Visual Modflow. La masa de agua de los Montes Torozos se trata de un acuífero kárstico libre y colgado de origen sedimentario, y su balance está determinado por las precipitaciones y por el drenaje.

The old Senhora das Fontes uranium mine, in central Portugal, consists of quartz veins which penetrated along fracture shear zones at the contact between graphite schist and orthogneiss. The mine was exploited underground until a depth of 90 m and was closed down in 1971. The ores from this mine and two others were treated in the mine area by the heap-leach process which ended in 1982. Seven dumps containing a total of about 33,800 m3 of material and partially covered by natural vegetation were left in the mine area. A remediation process took place from May 2010 to January 2011. The material deposited in dumps was relocated and covered with erosion resisting covers. Surface water and groundwater were collected in the wet season just before the remediation, in the following season at the beginning of the remediation and also after the remediation in the following dry season. Before, at the beginning and after the remediation, surface water and groundwater have an acid-to-alkaline pH, which decreased with the remediation, whereas Eh increased. In general, before the remediation, uranium concentration was up to 83 μg/L in surface water and up to 116 μg/L in groundwater, whereas at the beginning of the remediation it increases up to 183 μg/L and 272 μg/L in the former and the latter, respectively, due to the remobilization of mine dumps and pyrite and chalcopyrite exposures, responsible for the pH decrease. In general, after the remediation, the U concentration decreased significantly in surface water and groundwater at the north part of the mine area, but increased in both, particularly in the latter up to 774 μg/L in the south and southwest parts of this area, attributed to the remobilization of sulphides that caused mobilization of metals and arsenic which migrated to the groundwater flow. Uranium is adsorbed in clay minerals, but also in goethite as indicated by the geochemical modelling. After the remediation, the saturation indices of oxyhydroxides decrease as pH decreases. The remediation also caused decrease in Cd, Co, Cr, Ni, Pb, Zn, Cu, As, Sr and Mn concentrations of surface water and groundwater, particularly in the north part of the mine area, which is supported by the speciation modelling that shows the decrease of most dissolved bivalent species. However, in general, after the remediation, Th, Cd, Al, Li, Pb, Sr and As concentrations increased in groundwater and surface water at south and southwest of the mine area. Before and after the remediation, surface water and groundwater are contaminated in U, Cd, Cr, Al, Mn, Ni, Pb, Cu and As. Remediation caused only some improvement at north of the mine area, because at south and southwest part, after the remediation, the groundwater is more contaminated than before the remediation.

The Pinhal do Souto mine exploited a quartz vein containing uranium minerals, mainly autunite and torbernite. This vein intersects a two-mica granite containing 10 ppm U and uraninite. The mine was exploited underground and produced 93091 kg U3O8 between 1978 and 1989 and was then closed down. Two dumps were left in the mine area and these are partially covered by natural vegetation. Groundwater and surface water have a similar slightly acid-to-alkaline pH. The 2  2 UO is abundant and complexed with 2  3 CO , under neutral to alkaline pH. Metals and arsenic concentrations in the water increase during the dry season due to the evaporation. Uranium concentration in the water increases (up to 104.42 g/l) in the wet season, because secondary uranium minerals are dissolved and uranium is released into the water. Soils tend to retain a higher concentration of several metals, including U (up to 336.79 mg/kg) than stream sediments (up to 35.68 mg/kg), because vermiculite from the former could adsorb it more easily than could kaolinite from the latter. The Fe-oxides precipitate retains the highest concentrations of several metals, including U and Th (up to 485.20 and 1053.12 mg/kg, respectively) and the metalloid As, because it is richer in oxyhydroxides and organic matter than stream sediments and soils. The median concentrations of Fe, As, Cd, Pb, Sb, Th, U, W and Zn in soils from this area are higher than in European soils of the FOREGS data. Waters from dry and wet seasons, stream sediments and soils are contaminated and must not be used. This area was compared with another Portuguese abandoned uranium mine area. The former mine caused a lower environmental impact attributable to it having lower sulfide concentration and mineral alteration than in the latter.

Este artigo deriva de uma comunicação apresentada em International workshop “Uranium, Environment and Public Health”

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Resumo alargado da comunicação oral apresentada na 6th International Conference on Environmental Science and Development.

Ischnura graellsii (Insecta: Odonata) a water pollution biovulnerability indicator-probability mapping using spatial uncertainty.

Geostatistics tailored to address nitrates spatial uncertainty in groundwater (Douro Watershed, Spain).

The management of water resources is a priority for development of the places and welfare of people that supply, especially in water bodies most affected by anthropic pressures. Moreover, the increasing of sudden and extreme climatic phenomena appearance urges to resource planning in specific situations. In this research, the evolution of the piezometric surface has been simulated as the basis of a flow model draft, in the karstic aquifer of Cuellar Moor, located in the Douro watershed, all along the hydrologic years between 2010 and 2012. The use of geostatistical tools has been the starting point for estimating the piezometric surfaces, based on the median values. From the point of view of planning two scenarios showing extreme situations have been simulated: one of them synthesizes the most favorable conditions, in which piezometric level is at the recorded highest median levels (wet scenario); and the other one synthesizes the toughest conditions with the lowest recorded median piezometric levels (dry scenario). It likewise shows the estimated nitrate concentrations surface.

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Industrial and agricultural activities heavily constrain soil quality. Potentially Toxic Elements (PTEs) are a threat to public health and the environment alike. In this regard, the identification of areas that require remediation is crucial. In the herein research a geochemical dataset (230 samples) comprising 14 elements (Cu, Pb, Zn, Ag, Ni, Mn, Fe, As, Cd, V, Cr, Ti, Al and S) was gathered throughout eight different zones distinguished by their main activity, namely, recreational, agriculture/livestock and heavy industry in the Avilés Estuary (North of Spain). Then a stratified systematic sampling method was used at short, medium, and long distances from each zone to obtain a representative picture of the total variability of the selected attributes. The information was then combined in four risk classes (Low, Moderate, High, Remediation) following reference values from several sediment quality guidelines (SQGs). A Bayesian analysis, inferred for each zone, allowed the characterization of PTEs correlations, the unsupervised learning network technique proving to be the best fit. Based on the Bayesian network structure obtained, Pb, As and Mn were selected as key contamination parameters. For these 3 elements, the conditional probability obtained was allocated to each observed point, and a simple, direct index (Bayesian Risk Index-BRI) was constructed as a linear rating of the pre-defined risk classes weighted by the previously obtained probability. Finally, the BRI underwent geostatistical modeling. One hundred Sequential Gaussian Simulations (SGS) were computed. The Mean Image and the Standard Deviation maps were obtained, allowing the definition of High/Low risk clusters (Local G clustering) and the computation of spatial uncertainty. High-risk clusters are mainly distributed within the area with the highest altitude (agriculture/livestock) showing an associated low spatial uncertainty, clearly indicating the need for remediation. Atmospheric emissions, mainly derived from the metallurgical industry, contribute to soil contamination by PTEs.

Monitoring changes of anthropogenic impacts from a broad scope of species in biodiversity research require practical, easy-to-use and efficient assessment as well as monitoring methods. Odonates (Insecta: Odonata) are a valuable tool for assessing freshwater systems’ quality and have been used as bioindicators of environmental variety. The Águeda watershed, located in the central west of the Iberian Peninsula, shows an exponential increase in the last 60 years of natural resource exploitation coupled with alterations in consumer habits, causing significant environmental changes and deferred direct effects on the natural habitats. Fourteen river sites, selected a priori, were sampled. Adult odonates were collected using standardized methods. Selected environmental variables and water quality parameters were evaluated in situ. Precipitation and altitude were the most important physical, environmental variables in explaining the assemblage structure. Meaningful abiotic–biotic as well as biotic–biotic relationships were set up. Furthermore, situations in the urbanized watershed area showed to be highly impacted and closely related with damselfly Ischnura graellsii, which should be targeted as a possible vulnerability indicator for polluted fresh waters. A probability map for Ischnura graellsii distribution was performed using indicator kriging with external drift and spatial uncertainty obtain through the calculation of two categorical maps (binary), corresponding to the mean (0.485) and the trimmed mean by discharging the 10% lower distribution tail (0.533). The subsequent overlapping of both categorical maps (binary) allowed the definition of the higher spatial uncertainty map for surface water contamination.

In the abandoned Mortórios uranium mine area there are quartz veins containing wolframite and sulphides and basic rock dykes with torbernite and autunite cutting a porphyritic granite. The basic rock dykes were exploited and produced about 27 t of U3O8, from 1982 to 1988. There are an open pit lake and nine dumps. Surface water and groundwater are contaminated in U, As, Cd, Cr, Cu, Fe, Mn, Ni and Pb. Stream sediments are contaminated in U, As, Th and W, which are adsorbed by smectite, kaolinite and iron- and aluminium- oxy-hydroxides. The maximum U concentrations are of 1268 μg/L in the open pit lake, 100 μg/L in surface water, 103 μg/L in groundwater and 81.5 mg/kg in stream sediments all downstream of the open pit lake and dumps. Further downstream the U concentration in water decreases, due to the high mobility of U (VI), but the U concentration in stream sediments increases. Calcium uranyl carbonate dominates in the open pit lake, but uranyl carbonate complexes dominate in surface water and groundwater. The maximum As concentrations are 56.0 μg/L in the open pit lake, 63.4 μg/L in the surface water and 66.7 μg/L in the groundwater, both downstream of the open pit lake and dumps. The arsenic occurs as As (V). The Mortórios area is compared with two other areas exploited from open pits, all located in the uranium-bearing Beira area of central Portugal. Vale de Abrutiga produced 90 t of U3O8 between 1982 and 1989 and Mondego Sul produced 75 t of U3O8 from 1987 to 1991. The two mines consist of quartz veins containing sulphides, saleeite and meta-saleeite at Vale de Abrutiga and with sulphides, autunite, torbernite, meta-uranocircite and meta-saleeite at Mondego Sul cutting the Schist-graywacke Complex. The mine area of Vale de Abrutiga with the highest exploitation of U3O8 has strongly acidic to slight alkaline water, which is the most contaminated. Mortórios with the lowest exploitation presents a higher contamination of slightly acidic to alkaline water than that of acidic to alkaline water from Mondego Sul, but the former has As (V), whereas the latter has As (III), which is toxic. The stream sediments from Mortórios present the lowest contamination, except for Th that has a higher median value than that from Vale de Abrutiga. Stream sediments from Mondego Sul have higher U, Th, Pb and lower Co, Cr, Cu and Zn median values than those of Vale de Abrutiga.

The Picoto mining area is in the village of Vilar Seco (Viseu), central Portugal. Mineralization occurs mainly in quartz veins with meta-torbernite and uranophane and some U-bearing minerals, cutting a Variscan granite. Exploitation took place in two phases, between 1917 and 1953, and since the closure, the area has never been remediated. Water–rock interaction processes, including the mobility of potentially toxic elements through soil and water (surface and groundwater), were identified with the determination in situ of physicochemical parameters and selected anions and cations, by ICP-OES. The soils are contaminated with As (>44 mg/kg), Cu (>23 mg/kg), and U (>40 mg/kg) and cannot be used for agricultural or domestic purposes. The waters are generally weakly mineralized and have pH values ranging from acidic to neutral. However, some of them are contaminated with NO2 (up to 2.3 mg/L), Fe (up to 1849 mg/L), Mn (up to 777 mg/L), Cu (up to 5.4 g/L), As (up to 14.7 g/L), and U (up to 66.2 g/L) and cannot be used for human consumption or agricultural activities. The soil and water contamination are mainly related to the old mine activities and the subsequent human activities that have developed in the area.

This work focuses on the study of water–sediment interaction around abandoned uranium mines with open-pit lakes and mine dumps. Nineteen water and eleven stream sediment samples were collected in the abandoned Barrôco D. Frango mine, central Portugal. The trace element distribution was compared with other abandoned uranium mines in Portugal and worldwide. Generally, U, Th, and As contents in the open-pit water are high and similar to those of downstream water, suggesting its influence on aquatic systems. In abandoned mines with small to medium U exploitation, the stream sediments are moderately to heavily contaminated with U, Th and As, being U and As the most important contaminants, confirmed by their partition coefficients. A moderate to considerable potential ecological risk (34–79) was found around the abandoned Barrôco D. Frango mine area, mainly due to As contents in stream sediments. Water and stream sediments from abandoned U mines worldwide have U levels of up to 436 μg/L and 5024 mg/kg, respectively, while those from Barrôco D. Frango have 37.3 μg/L and 189 mg/kg, respectively. However, the longer the distance from the Barrôco D. Frango open-pit lake and mine dump, the higher U, Th and As contents in stream sediments, which is a warning indicator. Cluster heat maps of the water composition from four abandoned uranium mine areas show that Mondego Sul and Barrôco D. Frango mines are the most geochemically similar. Results show that stream sediments should be included in water quality management and future remediation plans of abandoned uranium mines.

Comunicação oral da qual só está disponível o resumo.

The final publication is available at Springer via http://dx.doi.org/10.1007/s10653-017-9945-2

A obra é constituída pelos resumos das comunicações apresentadas pelos docentes da Escola Superior Agrária do Instituto Politécnico de Castelo Branco e são referentes aos projetos de investigação nos quais estão envolvidos.

“This is a post-peer-review, pre-copyedit version of an article published in Environmental Geochemistry and Health. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10653-019-00347-x”.