Seasonal impact of acid mine drainage on water quality and potential ecological risk in an old sulfide exploitation.

Sulfides are usually associated with deposits of metals and coal. The reactive wastes from their exploitation, typically stored in piles and tailings dams, are often the mining sector's primary source of environmental problems. The surrounding river waters can present signs of acid mine drainage, responsible for aquatic ecosystem degradation. So, the main target of the present study is to investigate the impact of this process on the water's environmental quality and potential ecological risk. The study area is located at the Iberian Pyrite Belt, in an old sulfide exploitation, closed without environmental rehabilitation measures. The results exhibit high sulfate concentrations (410,601 mg/L) and potentially toxic elements, with prominence of Fe (134,000 mg/L), overcoming many other extreme cases of AMD pollution. The Ficklin diagram exposes that most samples are classified as "high-acid, high-metal." Two of them have extreme classifications (high-acid, extreme-metal). The pH value is well below the acceptable range for the environmental quality of superficial waters (5-7), measuring at a minimum of 0.84. Regarding seasonal variability, the study showed a higher degree of contamination in dry conditions (e.g., 4,420 mg/L of Cu), while the rainy month had lower concentrations of PTE (186.8 mg/L of Cu for the same sampling point). In addition, the water does not accomplish the environmental objectives established by the EU Water Framework Directive. According to the new approach developed based on a scale adjustment, the potential ecological risk index studied indicates that most sampled sites present strong, very strong, and even extremely potential ecological risk. With a typical Mediterranean climate, the region suffers from water scarcity, predicting increasingly in the future more degrading scenarios for water environmental quality. Consequently, urgent mitigation and remediation measures are necessary to improve and preserve water quality and fulfill the objectives of the United Nations Sustainability Development Goals.

Geochemistry and mineralogy of auriferous tailings deposits and their potential for reuse in Nova Lima Region, Brazil.

Since the mid-nineteenth century, gold ores, mainly hosted in sulfides, have been processed at metallurgical plants located in Nova Lima, Brazil. The generated wastes have been accumulated over the years in tailings dams or in piles. These materials represent wasted from old circuits, as well as from plants still in production. In this study, geochemical, mineralogical, 3D modelling, and metallurgical analyses wastes were carried out to evaluate potential reuse of these wastes. The performed characterization detected residues of very fine grain size containing sulfides and oxides. The wastes show high grades of Au hosted in different minerals. In addition to Au, samples contain S, Fe, Zn, Pb, Sc, Si, and As. The 3D modelling for spatial definition of Au was performed using ordinary kriging with dimensional variograms. The results indicated the occurrence of Au enrichment zones and allowed to reveal the most attractive tailing deposits in terms of Au content. Metallurgical tests showed recovery of 70% of Au and suggested other potential reuse of the wastes, such as aggregates for the civil construction sector and recovery of other metals. The present work highlights the importance of an integrative characterization within the scope of the circular economy and the value of tailings in the production chain of the mineral sector.

Rare earth elements - Source and evolution in an aquatic system dominated by mine-Influenced waters.

Acid mine drainage (AMD), formed by the instability of sulfides, typically generates acidity and releases potentially toxic elements and sulfate to the environment, among other pollutants. An example is the group of rare earth elements (REE) that may have high toxic behavior. This toxicity leads to degradation of soils, water reservoirs and rivers, promoting serious risks for the ecosystems. So, the main goal of the present work is to study the hydrochemical properties of a system with mine-influenced waters during the rainy season, focusing on the origin, evolution/behavior, and concentration of REE. The study area is the São Domingos mining complex, located in one of the largest metallogenetic provinces in the world (Iberian Pyrite Belt), known by the evidences of AMD contamination. The obtained results reveal extraordinarily low pH (0.4), high electrical conductivity, reaching 26,200 µS/cm, and high values of sulfate and acidity. Regarding the REE, the determined concentration exceeded that observed in normal pH of neutral freshwaters by 2-3 times the order of magnitude. The results revealed that Y and Ce are distinguished in practically all sampled sites, due to its higher concentrations, with maximum values of 221.8 and 166.9 µg/L. In general, the concentrations increase as the water pH decreases. The statistical analysis indicates that REE elements may have a common origin, mutual dependence, and similar behavior during transport with typical AMD elements and composition of host rocks. Most samples show enrichment in middle REE (MREE) (Gdn/Lun), like the classic signature of AMD. In turn, colloids and AMD-precipitates may be participating in the incorporation of these elements. Therefore, due to potential risk of impacts on ecosystems, REE are a topic of relevant interest for future studies in order to assist monitoring processes and help government decisions related to water quality management.

The impact of remote work on worker's health.

Remote work was brought to the forefront with the arrival of the COVID-19 public health emergency. Although there is no evidence of a direct cause-and-effect relationship between venous disease and work, the current medical consensus is that work can severely intensify its progression. Here, we report the case of a worker at a financial institution, who had been working remotely for around one year and had stopped exercising regularly for the same period. In January 2021, he presented intense pain and marked edema in the soleus area of the right lower limb, which prompted a visit to the emergency department. Laboratory analyses showed slight increases in d-dimer (720 ng/mL) and C-reactive protein (5 mg/dL) levels. A venous Doppler ultrasound of the lower limbs revealed the presence of an occlusive thrombus in the right soleus veins, reaching the right popliteal vein with associated venous dilation. The diagnosis of right, popliteal-distal acute deep vein thrombosis was thus reached. It is clearly impossible to change some of the risk factors of chronic venous insufficiency; however, other aspects such as obesity and working conditions can be the object of preventive actions that generate changes. We thus highlight the importance and possibility of a multidisciplinary approach to this theme, which could evolve into the establishment of a protocol for the prevention and treatment of venous diseases according to each job position.

O home office ganhou um papel de destaque com a chegada da emergência de saúde pública relativa à COVID-19. Embora não haja evidência da relação direta de causa e efeito de doença venosa com o trabalho, existe consenso atual, na opinião médica, de que o trabalho pode agravar seriamente o seu desenvolvimento. É relatado o caso de um profissional de instituição bancária, em teletrabalho há cerca de 1 ano, momento em que suspendeu também a prática de exercício físico. Em janeiro de 2021, iniciou quadro de dor intensa e edema acentuado na região solear do membro inferior direito, motivo pelo qual recorreu ao Serviço de Urgência. No estudo analítico, foram destacadas ligeiras elevações dos D-dímeros (720 ng/mL) e proteína C-reativa (5 mg/dL). A ecografia com estudo de Doppler venoso dos membros inferiores revelou presença de trombo oclusivo nas veias soleares direitas com extensão à veia poplítea direita com dilatação venosa associada. Admitiu-se, então, o diagnóstico de trombose venosa profunda poplíteo-distal direita de características agudas. É evidente que é impossível modificar alguns dos fatores de risco para a insuficiência venosa crônica; porém, outros fatores como obesidade e condições de trabalho podem ser alvo de ações preventivas que gerem modificações. Assim, ressaltam-se a importância e a possibilidade da abordagem multidisciplinar ao tema, o que poderia evoluir para o estabelecimento de um protocolo de prevenção e tratamento de doenças venosas em função do posto de trabalho executado.

Tuberculosis, an unusual source - a case report.

Tuberculosis is an infectious disease caused by bacteria in the Mycobacterium tuberculosis complex. It can affect any organ, but the pulmonary form is the most common manifestation. Not only humans can be affected by tuberculosis, and animals are also commonly infected. This disease can be transmitted to humans usually by inhalation of aerosols or by ingestion of unpasteurized milk or dairy products. We report the case of a zoo worker. He reported an epidemiological context of contact with sea lions and dolphins, of which he takes care, with tuberculosis in the last 4 months. He sought permanent medical care for a 3-week history of cough, fever, sweating, and weight loss. Bronchial lavage was positive for acid-alcohol resistant bacilli. Lavage cultures were positive for the M. tuberculosis complex. The patient was referred for treatment with antituberculosis drugs. Tuberculosis is a major public health problem worldwide. In the occupational setting, tuberculosis remains a matter of great concern and attention, most often in the hospital environment or among health care professionals. However, the case reported here shows another, less usual occupational setting in which this type of contact can also occur. It is expected that the warning of this case can be used by occupational health teams, namely those who are responsible for periodic surveillance of workers' health in the animal sector.

A tuberculose é uma doença infecciosa causada por bactérias do Mycobacterium tuberculosis complex. Pode atingir qualquer órgão, sendo a forma pulmonar a mais frequente. Não só os humanos podem ser atingidos pela tuberculose, sendo também muito comum a existência de infecção de animais. Essa patologia pode espalhar-se para os humanos, normalmente pela inalação de aerossóis ou pela ingestão de leite ou derivados não pasteurizados. Trata-se do caso de um trabalhador de zoológico, com contexto epidemiológico de contato com leões-marinhos com tuberculose nos últimos 4 meses. Recorreu a atendimento permanente por história de 3 semanas de tosse, febre, sudorese e perda ponderal. A pesquisa de bacilos resistentes a álcool-ácido no lavado brônquico revelou-se positiva. Quanto ao exame cultural do lavado, concluiu-se positivo para M. tuberculosis complex. Foi, então, realizado o devido encaminhamento, e o paciente iniciou tratamento com antibacilares. A tuberculose constitui um importante problema de saúde pública em nível global. No contexto ocupacional, mantém-se como um motivo de grande preocupação e atenção, mais frequentemente em meio hospitalar ou entre os profissionais de saúde. No entanto, este caso mostra outro contexto ocupacional, menos óbvio, em que este tipo de contato também pode acontecer. Espera-se que o alerta do presente caso possa ser utilizado pelas equipas de saúde ocupacional, nomeadamente as que realizam vigilância periódica a trabalhadores do setor animal.

Photosynthetic pigments in acid mine drainage: Seasonal patterns and associations with stressful abiotic characteristics.

Acid mine drainage represents an extreme type of water pollution. The environments develop especial hydrochemical and ecological characteristics, such as high concentrations of acidity and low biodiversity, with dominance of acidophilic organisms. Ecological criteria are assuming increasing relevance for assessing water quality, including in acid mine drainage-affected systems. Photosynthetic pigments, like chlorophyll, could be considered in this context as they are generally used to estimate phytoplankton biomass. The present work was focused on acid mine drainage and their relationships with chlorophyll a. It was developed in the historic mine of São Domingos (Iberian Pyrite Belt, SW Europe). The methodological approach comprised two sampling campaigns (October and February) to represent seasonal behaviour. The diversity of hydrological conditions was also considered through sampling sites established in the pit lake, acidic lagoons and affected stream. Hydrochemistry and chlorophyll a were analysed. The obtained results revealed very low pH values, with a minimum of 2.1. In general, hydrochemistry indicates higher concentrations of pollutants in summer. One of the sampling point, located in an acidic lagoon, stood out by highest concentrations, presenting maximum of sulfate (6564 mg/L), As (6.26 mg/L), and metals like Al (675 mg/L), Cd (1,30 mg/L), Zn (199 mg/L). These highest concentrations coincided with the maximum concentration of chlorophyll a (113 µg/L). The results suggested that the more contaminated the environment, more chlorophyll a was produced. Factor analyses emphasised the relationships between acid drainage properties and the photosynthetic activity, indicating a strong pH dependency of chlorophyll a production.

Are Cu isotopes a useful tool to trace metal sources and processes in acid mine drainage (AMD) context?

In the South-West Europe (Iberian Pyrite Belt), acid mine drainage (AMD) processes are especially problematic because they affect the environmental quality of watersheds, restricting the use of surface water. Recent studies have shown that Cu isotopes are fractionated during the oxidative dissolution of primary sulfide minerals and could be used to trace metal cycling. However the chemistry of Cu in such environment is complex because Cu is redistributed within numerous secondary minerals and strongly dependent on the hydroclimatic conditions that control key parameters (pH, redox conditions). Finally, it remains difficult to compare the various field studies and deliver some strong general tendencies because of these changing conditions. For these reasons, concerted studies on Cu isotopes fractionation in waters impacted by AMD may help to reveal the sources and transport pathways of this important pollutant. To address this issue, we used a representative scenario of strong contamination by AMD in the Iberian Pyrite Belt (SW Spain), the Cobica River. The aim of our study is to measure the Cu isotopes signature in the waters (river, mine lake, water draining waste) of the small Cobica River system (Huelva, Spain), sampled during a short period (8 h) to avoid any change in the hydro-climatic conditions. This provided an instantaneous image of the isotopic Cu signature in a small mining systems and helped us to constrain both the processes affecting Cu isotopes and their use a potential tracer of metals in contaminated environments.

Enrichment of trace elements in the clay size fraction of mining soils.

Reactive waste dumps with sulfide minerals promote acid mine drainage (AMD), which results in water and soil contamination by metals and metalloids. In these systems, contamination is regulated by many factors, such as mineralogical composition of soil and the presence of sorption sites on specific mineral phases. So, the present study dedicates itself to understanding the distribution of trace elements in different size fractions (<2-mm and <2-µm fractions) of mining soils and to evaluate the relationship between chemical and mineralogical composition. Cerdeirinha and Penedono, located in Portugal, were the waste dumps under study. The results revealed that the two waste dumps have high degree of contamination by metals and arsenic and that these elements are concentrated in the clay size fraction. Hence, the higher degree of contamination by toxic elements, especially arsenic in Penedono as well as the role of clay minerals, jarosite, and goethite in retaining trace elements has management implications. Such information must be carefully thought in the rehabilitation projects to be planned for both waste dumps.

Widespread Environmental Contamination with Mycobacterium tuberculosis Complex Revealed by a Molecular Detection Protocol.

Environmental contamination with Mycobacterium tuberculosis complex (MTC) has been considered crucial for bovine tuberculosis persistence in multi-host-pathogen systems. However, MTC contamination has been difficult to detect due to methodological issues. In an attempt to overcome this limitation we developed an improved protocol for the detection of MTC DNA. MTC DNA concentration was estimated by the Most Probable Number (MPN) method. Making use of this protocol we showed that MTC contamination is widespread in different types of environmental samples from the Iberian Peninsula, which supports indirect transmission as a contributing mechanism for the maintenance of bovine tuberculosis in this multi-host-pathogen system. The proportion of MTC DNA positive samples was higher in the bovine tuberculosis-infected than in presumed negative area (0.32 and 0.18, respectively). Detection varied with the type of environmental sample and was more frequent in sediment from dams and less frequent in water also from dams (0.22 and 0.05, respectively). The proportion of MTC-positive samples was significantly higher in spring (p<0.001), but MTC DNA concentration per sample was higher in autumn and lower in summer. The average MTC DNA concentration in positive samples was 0.82 MPN/g (CI95 0.70-0.98 MPN/g). We were further able to amplify a DNA sequence specific of Mycobacterium bovis/caprae in 4 environmental samples from the bTB-infected area.

Geochemistry of rare earth elements in a passive treatment system built for acid mine drainage remediation.

Rare earth elements (REE) were used to assess attenuation processes in a passive system for acid mine drainage treatment (Jales, Portugal). Hydrochemical parameters and REE contents in water, soils and sediments were obtained along the treatment system, after summer and winter. A decrease of REE contents in the water resulting from the interaction with limestone after summer occurs; in the wetlands REE are significantly released by the soil particles to the water. After winter, a higher water dynamics favors the AMD treatment effectiveness and performance since REE contents decrease along the system; La and Ce are preferentially sequestered by ochre sludge but released to the water in the wetlands, influencing the REE pattern of the creek water. Thus, REE fractionation occurs in the passive treatment systems and can be used as tracer to follow up and understand the geochemical processes that promote the remediation of AMD.

Neuralgia pós-herpética: dois casos clínicos / Postherpetic neuralgia: two clinical cases / Neuralgia postherpética: dos casos clínicos

A neuralgia pós-herpética (NPH) é a complicação mais frequente do herpes-zóster, caracterizando-se pela presença de dor tipo neuropática de distribuição dermatômica, após manifestação prévia de um quadro agudo de herpes-zóster, geralmente um mês depois do surgimento das vesículas. O objetivo do presente relato é apresentar dois casos clínicos de NPH e suas respostas a diferentes tratamentos. O primeiro caso apresentou intolerância à amitriptilina e uma boa resposta clínica à gabapentina na dosagem de 900 mg/dia. O segundo caso apresentou intolerância à capsaicina, mas apresentou boa resposta à combinação da pregabalina com lidocaína tópica. A gabapentina, a pregabalina e a lidocaína tópica são tratamentos eficazes para o tratamento da neuralgia pós-herpética. Todas essas recomendações vão ao encontro dos tratamentos utilizados pelos médicos de família nos dois casos apresentados neste estudo.

Postherpetic neuralgia (PHN) is the most common complication of Herpes Zoster, characterized by the presence of neuropathic-type pain limited to a dermatomic area after outbreak of Herpes Zoster (commonly known as shingles), usually a month after the appearance of vesicles on the skin . The aim of this report is to present two cases of PHN and their responses to different treatments. The first case presented intolerance to amitriptyline and a good clinical response to gabapentin at a dose of 900 mg/day. The second case showed intolerance to capsaicin but responded well to the combination of pregabalin and topical lidocaine. Gabapentin, pregabalin and lidocaine are effective for the treatment of postherpetic neuralgia. All these recommendations are consistent with those treatments used by the family physicians in the two cases study presented.

La neuralgia postherpética (NPH) es la complicación más común de herpes zoster, que se caracteriza por la presencia de dolor tipo neuropático de distribución dermatómica después de una manifestación previa de cuadro agudo de Herpes Zoster, generalmente un mes después de la aparición de las vesículas en la piel. El objetivo de este relato es presentar dos casos de NPH y sus respuestas a diferentes tratamientos. El primer caso presento intolerancia a la amitriptilina y una buena respuesta clínica a la gabapentina en la dosis de 900 mg/día. El segundo caso mostró intolerancia a la capsaicina, pero mostró una buena respuesta a la combinación de pregabalina associado con lidocaína tópica. La gabapentina, pregabalina y la lidocaína son eficaces para el tratamiento de la neuralgia postherpética. Todas estas recomendaciones son coherentes con los tratamientos utilizados por el médico de familia en dos casos presentados en este estudio.

Metal uptake by native plants and revegetation potential of mining sulfide-rich waste-dumps.

Waste dumps resulting from metal exploitation create serious environmental damage, providing soil and water degradation over long distances. Phytostabilization can be used to remediate these mining sites. The present study aims to evaluate the behavior of selected plant species (Erica arborea, Ulex europaeus, Agrostis delicatula, and Cytisus multiflorus) that grow spontaneously in three sulfide-rich waste-dumps (Lapa Grande, Cerdeirinha, and Penedono, Portugal). These sites represent different geological, climatic and floristic settings. The results indicate distinctive levels and types of metal contamination: Penedono presents highest sulfate and metal contents, especially As, with low levels of Fe. In contrast, at Lapa Grande and Cerdeirinha Fe, Mn, and Zn are the dominant metals. In accordance, each waste dump develops a typical plant community, providing a specific vegetation inventory. At Penedono, Agrostis delicatula accumulates As, Pb, Cu, Mn, and Zn, showing higher bioaccumulation factors (BF) for Mn (32.1) and As (24.4). At Cerdeirinha, Ulex europaeus has the highest BF for Pb (984), while at Lapa Grande, Erica arborea presents high BF for Mn (9.8) and Pb (8.1). Regarding TF, low values were obtained for most of the metals, especially As (TF < 1). Therefore, the results obtained from representative plant species suggest appropriate behavior for phytostabilization measures.