RESUMO
In May 2017, a spill from La Zarza pit lake (SW Spain) resulted in the release of approximately 270,000â¯m3 of extremely acidic waters to the Odiel River. Around 780â¯×â¯103â¯kg of Fe, 170â¯×â¯103â¯kg of Al, 2.15â¯×â¯103â¯kg of As and high amounts of other trace metals and metalloids were spilled. The purpose of this study is to explain the causes, consequences and impacts of the mine spill on the receiving water bodies. To this end, an extensive sampling along the mine site, river and estuary as well as a hydrological model of the pit lake was performed. Around 53â¯km of the Odiel River's main course, which was already contaminated by acid mine drainage (AMD), were affected. The mine spill resulted in an incremental impact on the Odiel River water quality. Thus, dissolved concentrations of some elements increased in the river up to 450 times; e.g. 435â¯mg/L of Fe and 0.41â¯mg/L of As. Due to low pH values (around 2.5), most metals (e.g., Cu, Zn, Mn, Cd) were transported in the dissolved phase to the estuary, exhibiting a conservative behavior and decreasing their concentration only due to dilution. However, dissolved concentrations of Fe, Cr, Pb, Se, Sb, Ti, V and especially As decreased significantly along the river due to Fe precipitation and sorption/coprecipitation processes. At the upper zone of the estuary, a noticeable increment of metal concentrations (up to 77 times) was also recorded. The water balance illustrates the existence of groundwater inputs (at least 16% of total) to the pit lake, due probably to local infiltration of rainwater at the mining zone. The probable existence of an ancient adit connected to the pit lake indicates that potential releases could occur again if adequate prevention measures are not adopted.
Assuntos
Ácidos/análise , Monitoramento Ambiental/métodos , Lagos/química , Metais/análise , Mineração , Rios/química , Poluentes Químicos da Água/análise , Ácidos/toxicidade , Estuários , Ferro/análise , Espanha , Sulfetos/análise , Qualidade da ÁguaRESUMO
The concentration of meteoric 10Be in estuarine sediment samples has been measured by Spanish Accelerator for Radionuclides Analysis (SARA) at CNA and subsequently used to assess the denudation rate in Guadiana river basin together with the sediment budget method, on both sides of the frontier between Spain and Portugal. The two methods yielded coincident results. The estimation by the 10Be method gave the denudation rate of (0.76⯱â¯0.10)â¯×â¯10-2â¯cm/y. After correcting for an approximate 80% attenuation of the sediment discharge into the ocean, caused by the river dams, the sediment budget method yielded the rate of (0.77⯱â¯0.17)â¯×â¯10-2â¯cm/y.
Assuntos
Berílio/análise , Monitoramento de Radiação , Radioisótopos/análise , Rios/química , Poluentes Radioativos da Água/análise , Sedimentos Geológicos/química , EspanhaRESUMO
Spirocerca lupi Rudolphi 1809 (Nematoda Spirocercidae) has an indirect cycle involving intermediate and paratenic hosts, having domestic or wild canids as the main definitive hosts. The most frequent pathology affecting dogs is a granulomatous tumor-like growth containing adults in the oesophagus and aorta. There are very few references about the presence of nodules in the stomach. There is scant information about the epidemiology of this disease in wild red foxes in meso-Mediterranean areas. In this work we report on the natural infection of wild red foxes by Spirocerca lupi and the damage produced in the stomach wall in an area where contact with other potential definitive hosts (canids) is very rare. From July 2015 to November 2016, 61 red foxes were sampled. 18.03% of the stomach walls examined had nodules containing Spirocerca lupi adults and eggs. The prevalence of infection was similar for young and adult groups (23.81 and 18.18%; χ2â¯=â¯0.25; dfâ¯=â¯1; Pâ¯=â¯0.6171) and it was higher in females than in males (25.81 versus 10.00%, χ2â¯=â¯2.58; dfâ¯=â¯1; Pâ¯=â¯0.1082). The red fox population in the area seems to be well established judging from their age distribution and the fact that they could be captured all year round. It would appear that in the absence of other main definitive host S. lupi population is able to survive just parasitizing red foxes. Pathologic effects of this parasite on red foxes seems to show some differences related to domestic dogs. These results also indicates as predator control programs can maintain suitable host populations with reduced level of infection.
Assuntos
Reservatórios de Doenças/veterinária , Raposas/parasitologia , Infecções por Spirurida/veterinária , Estômago/parasitologia , Animais , Conservação dos Recursos Naturais , Reservatórios de Doenças/parasitologia , Feminino , Masculino , Região do Mediterrâneo/epidemiologia , Espanha/epidemiologia , Infecções por Spirurida/epidemiologia , Estômago/patologia , Thelazioidea/isolamento & purificaçãoRESUMO
Solid acid catalysts based on WO3-SiO2 and WO3-ZrO2-SiO2 were prepared by one-pot non-hydrolytic sol-gel method and tested in the gas phase glycerol dehydration to acrolein. Their structural and textural characteristics were determined by X-ray diffraction (XRD), N2 adsorption, X-ray energy dispersive spectroscopy (XEDS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Their acid characteristics were studied by both temperature programmed desorption of ammonia (NH3-TPD) and FTIR of adsorbed pyridine. Under our operating conditions, all the catalysts were active and selective in the transformation of glycerol to acrolein, which was always the main reaction product. The high selectivity to acrolein is achieved on catalysts presenting a higher proportion of Brønsted acid sites. In addition, the role of oxygen in the feed on catalytic performance of these catalysts is also discussed.
RESUMO
Huelva Estuary is a transition zone where REE-rich acidic waters interact with saline-alkaline seawater. This mixing process influences the geochemical and mineralogical characteristics of particulate and dissolved fractions. The Tinto River has >11,000µgL-1 dissolved REE (pH=1.66), whereas seawater only reaches 8.75·10-2µgL-1 dissolved REE (pH=7.87). REE-normalized patterns in "pH<6 solutions" are parallel and show similarities, diminishing their concentration as pH increases. Sequential extraction performed on the generated precipitates of mixed solutions indicates that most REE are associated to the residual phase. In a second order, REE are associated with soluble salts at pH3 and 3.5 whereas in sediments generated at pH4 and 5, they are distributed in salts (1° extraction), poorly crystallized Fe-bearing minerals (schwertmannite, 3° extraction) and well crystallized Fe-bearing minerals (goethite - hematite, 4° extraction). Finally, precipitated REE are highest at pH6 newly formed minerals with a release to solution in higher pH.
Assuntos
Estuários , Metais Terras Raras/análise , Monitoramento Ambiental , Água Doce , Água do Mar , Espanha , Poluentes Químicos da ÁguaRESUMO
The Iberian Pyrite Belt (SW Iberian Peninsula) has intense mining activity. Currently, its fluvial networks receive extremely acid lixiviate residue discharges that are rich in sulphates and metals in solution (acid mine drainage, AMD) from abandoned mines. In the current study, the sediment and water quality were analysed in three different areas of the Odiel River to assess the risk associated with the metal content and its speciation and bioavailability. Furthermore, sediment contact bioassays were performed using the freshwater clam Corbicula fluminea to determine its adequacy as a biomonitoring tool in relation to theoretical risk indexes and regulatory thresholds. Reburial activity and mortality were used as the toxic responses of clams when exposed to contaminated sediment. The results showed coherence between the water and sediment chemical contamination for most of the metals. The reburial activity was correlated with the metal toxicity, but no clam mortality was registered. The bioaccumulation of the studied metals in the clam did not have a significant correlation with the bioavailable fraction of the metal content in the environment, which could be related to a potential different speciation in this singular environment. The bioaccumulation responses were negative for As, Cd and Zn in highly contaminated environments and were characterized as severe, considerable and low potential environmental risks, respectively. The results show that C. fluminea is a good biomonitor of Cu and Pb.
Assuntos
Corbicula/metabolismo , Monitoramento Ambiental/métodos , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Metais/análise , Metais/toxicidade , Mineração , Espanha , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Scarcity of waters is the main limiting factor of economic development in most arid and semi-arid regions worldwide. The construction of reservoirs may be an optimal solution to assure water availability if the drainage area shows low disturbances. This is the quandary of mining areas where economic development relies on water accessibility. Water acidification trends were investigated in the Sancho Reservoir (SW Spain) in the last 20 years. The acidity (pH3-5) and high dissolved metal concentrations (e.g., 4.4 mg/L of Al, 2.1mg/L of Mn, 1.9 mg/L of Zn) observed in the Sancho, together with the large volume stored (between 37 and 55 Mm(3)), makes this reservoir an extreme case of surface water pollution worldwide. A progressive acidification has been observed since 2003, as evidenced by decreasing pH values and increasing dissolved metal concentrations, especially noticeable after 2007. The increase in the net acidity in the reservoir originates from the higher input of metals and acidity due to the rebound effect after the mining closure in 2001. This trend was not detected in the river feeding the reservoir due to its great hydrological and hydrochemical variability, typical of the Mediterranean climate. Chemical analysis and absolute dating of sediments identified a progressive enrichment in S and metals (i.e., Fe, Zn Cu, Ni, Co and Cd) in the upper 20 cm, which reinforce the year 2002/03 as the onset of the acidification of the reservoir. The decrease of pH values from 4-5 to 3-4 occurred later than the increase in sulfate and metals due to pH-buffering by Al. The acid mine drainage (AMD) pressure has caused an increment of dissolved Fe and other metals, as well as a change in the pH buffering role, exerted now by Fe. These processes were simulated by PHREEQC, which confirms that the acidification trend will continue, causing pH values to reach 2.5 if AMD pressure persists.
RESUMO
Hexagonal (W,V)O3-x oxides of high thermal stability have been synthesized hydrothermally through the intermediate products Nax(W,V)O3·zH2O and (NH4)0.33-x(W,V)O3-y. The obtained crystals show nanostructured surface via the formation of a dense population of polyhedral nanocavities self-distributed along particular crystallographic directions. Nanocavities present a regular size that ranges from 5 to 10 nm in both length and width. The synthesis process involves a significant topotactic relationship between the as-synthesized product and the desired final product and this relationship is suggested as the origin of the observed surface nanostructure. The comparison of our results with observations in different solids has allowed us to suggest that the formation of nanocavities is an extensive spontaneous process when materials are obtained by the chemical reactions of solids leading to products with defined crystallographic orientation with respect to the original compound. The characterization provides evidence regarding the potential relevance of nanocavities in the functional properties of the resulting solids.
RESUMO
The abandoned mining districts of the Iberian Pyrite Belt (IPB, SW Spain) are an extreme source of pollution by acid mine drainage (AMD) to the Tinto and Odiel rivers. The pollutant flux transported by the Odiel River during a high stage period was assessed using concentration-discharge relationships and concentration-conductivity relationships, for the hydrological year 2009/10 (which was especially wet). Both correlations were high (R(2)>0.80) for most of the elements studied. The two methods for flux calculation gave similar results with differences generally lower than 10%. The dissolved contaminant flux transported by the Odiel River just before its mouth mainly includes sulphate (257,534±13,464 t/yr), Al (13,259±1071 t/yr), Zn (4265±242 t/yr), Mn (2532±146 t/yr) and Cu (1738±136 t/yr), and minor amounts of other elements. These findings confirm that, up to our knowledge, the Odiel River can be considered to be the largest contributor of mining-related pollutants to the world's oceans.
RESUMO
BACKGROUND: Several authors have reported an increase in leukotriene C4 in the premenstrual phase in women with severe premenstrual asthma, indicating that antileukotrienes could be used in treatment. OBJECTIVE: To analyse the role of leukotrienes in premenstrual asthma. METHODS: A questionnaire on respiratory symptoms and peak flow during one complete menstrual cycle was given to women of fertile age to define them as asthmatics who suffered from premenstrual asthma or not. Premenstrual asthma (PMA) was defined as a clinical or functional deterioration (≥20%) in the premenstrual phase compared with the preovulatory phase. Blood samples to measure leukotriene C4 were taken during the preovulatory and premenstrual phases. RESULTS: Blood samples were taken in 62 asthmatic women, 34 of whom (54.3%) presented PMA criteria, all with a premenstrual deterioration of between 20 and 40%. There was no difference in leukotriene C4 levels between the preovulatory and premenstrual phases in the women who suffered from PMA (1.50ng/mL vs. 1.31ng/mL; p=0.32) and those who did not (1.40ng/mL vs. 1.29ng/mL; p=0.62). Neither were there any differences in leukotriene levels between women with or without PMA. The results were similar for each category of asthma severity. CONCLUSIONS: Our data show that leukotriene C4 does not appear to be involved in the pathogenesis of premenstrual asthma, or support the use of anti-leukotrienes in the specific treatment of premenstrual asthma, at least in women with a moderate premenstrual deterioration. No differences appeared in any of the categories of asthma severity.
Assuntos
Asma/diagnóstico , Leucotrieno C4/sangue , Síndrome Pré-Menstrual/diagnóstico , Adolescente , Adulto , Asma/imunologia , Progressão da Doença , Feminino , Humanos , Ciclo Menstrual/imunologia , Pico do Fluxo Expiratório , Síndrome Pré-Menstrual/imunologia , Inquéritos e Questionários , Adulto JovemRESUMO
OBJECTIVE: To analyse the quality of the prescription of home oxygen therapy (OT) in a health area of Murcia. METHODS: A prospective study of 125 patients in a respiratory therapy clinic, evaluated with a questionnaire and blood-gas analysis while breathing ambient air. Related respiratory therapy was also assessedin COPD and asthma patients. RESULTS: We studied 125 cases in the 3 months following the prescription of home oxygen therapy in 72 men (58%) and 53 women (42%) with a mean age of 77.2 ± 11.6. The most common type of home OT prescribed was for palliative cases in 45 patients (36%), followed by COPD in 42 (33.6%). In 88 (92%) of the 96 medical reports that we evaluated, insufficient data as to how to administer oxygen were available. Twenty-five percent of home OT prescriptions were given without blood-gas analyses, and in the 65 cases with a blood-gas analysis only 11 (17%) met oxygen value criteria for home OT as per regulations. Oxygen desaturation was not present in 31% of the palliative care home OT cases. The analysis of blood-gases during the clinic visit in non-palliative care cases demonstrated that 61% did not meet the blood-gas criteria to continue on home OT. Eighty percent of COPD and asthma patients on home OT did not receive the correct respiratory therapy. CONCLUSIONS: Quality problems in the prescription of home OT exist in our area. Palliative care is the principal reason for home OT prescriptions. In COPD and asthma patients who receive home OT, related respiratory therapy is not ideal.
Assuntos
Serviços de Assistência Domiciliar/estatística & dados numéricos , Oxigenoterapia , Prescrições/normas , Idoso , Idoso de 80 Anos ou mais , Asma/sangue , Asma/terapia , Monitorização Transcutânea dos Gases Sanguíneos/estatística & dados numéricos , Feminino , Cardiopatias/sangue , Cardiopatias/terapia , Humanos , Hipóxia/epidemiologia , Hipóxia/prevenção & controle , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/terapia , Oxigênio/sangue , Oxigenoterapia/normas , Oxigenoterapia/estatística & dados numéricos , Cuidados Paliativos , Pressão Parcial , Seleção de Pacientes , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/terapia , Espanha , Resultado do TratamentoRESUMO
In this study, two Membrane Biological Reactors (MBR) with submerged flat membranes, one at lab-scale conditions and the other at pilot-plant conditions, were operated at environmental temperature to treat an industrial wastewater characterised by low phenol concentrations (8-16 mg L(-1)) and high salinity (â¼ 150-160 mS cm(-1)). During the operation of both reactors, the phenol loading rate was progressively increased and less than 1mg phenol L(-1) was detected even at very low HRTs (0.5-0.7 days). Membrane fouling was minimized by the cross flow aeration rate inside the MBRs and by intermittent permeation. Microbial community analysis of both reactors revealed that members of the genera Halomonas and Marinobacter (gammaproteobacteria) were major components. Growth-linked phenol degradation by pure cultures of Marinobacter isolates demonstrated that this bacterium played a major role in the removal of phenol from the bioreactors.
Assuntos
Reatores Biológicos , Halomonas/metabolismo , Marinobacter/metabolismo , Fenóis/isolamento & purificação , Salinidade , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Biologia Computacional , Eletroforese em Gel de Gradiente Desnaturante , Condutividade Elétrica , Halomonas/genética , Marinobacter/genética , Espectrometria de Massas , Dados de Sequência Molecular , Fenóis/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme (δ-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagón, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ((206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50±1.09 µg g(-1) Pb d.w.) and D. trunculus (1.95±0.10 µg g(-1) Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels (<0.38 µg g(-1) Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD=-0.36[Pb]+0.79; r=0.837; or exponential for M. galloprovincialis ALAD=2.48e(-8.3[Pb]); r=0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in marine bivalve species with different feeding habits. Lead isotope data showed significant seasonal and spatial changes in bivalve isotopic composition reflecting seasonal and geographic differences in bioaccumulation. Within the study area, Pb can be modelled as a mixing between geogenic Pb and mine-related, discharges of Pb from the IPB. For some sites at the mouth of the Guadiana River, the bivalves show contamination from other anthropogenic sources, such as leaded boat/aviation fuel and/or leaded paint. Finally, the study demonstrates convincingly the need to consider species-specific variation when using bivalve ALAD activity as a biomarker for Pb.
Assuntos
Bivalves/metabolismo , Monitoramento Ambiental/métodos , Chumbo/toxicidade , Mineração , Sintase do Porfobilinogênio/metabolismo , Rios/química , Água do Mar/química , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Monitoramento Ambiental/estatística & dados numéricos , Isótopos/análise , Chumbo/análise , Espanha , Especificidade da Espécie , Poluentes Químicos da Água/análiseRESUMO
INTRODUCTION: In the prevention for being overweight and for obesity, much attention is given to the influence of dietary factors, making the joint evaluation with other modifiable factors necessary. OBJECTIVES: The aim of this project is to study the association between modifiable factors (physical activity, sedentary lifestyle, and dietary habits) with the prevalence of being overweight or obese in the youth population. METHODS: Cross-Sectional study of 1283 school children between the ages of 3 and 16 years old, with measurements of the MBI, dietary habits, physical activity, sedentary lifestyle and family history of being overweight. Physical activity measured in MET was classified according to Pate criteria. RESULTS: 22.4% of the boys and 32.9% of the girls were overweight. The presence of a BMI>25 in parents multiplied by 2.4 the risk of being overweight in children (OR CI 95% 1.5-3.7). 63.6% of overweight boys meet physical activity recommendations compared with 52.2% of girls, although in their case, it was greater than the average (45%). Sedentary time was 141 minutes for men and 128 minutes for women, with more sedentary behaviors associated with being overweight, especially in girls over 12 years of age (66.7%). Consuming cereal (OR 0.8) and having five meals per day (OR 0.5) act as protective factors. CONCLUSIONS: In subjects with overweight, the levels of physical activity are close to those recommended levels, so which the values of a sedentary lifestyle together with dietary habits (if the parents have overweight) acquire a new relevance in intervention strategies of this problem.
Assuntos
Comportamento Alimentar , Estilo de Vida , Obesidade/terapia , Sobrepeso/terapia , Adolescente , Índice de Massa Corporal , Criança , Pré-Escolar , Estudos Transversais , Exercício Físico , Feminino , Humanos , Masculino , Atividade Motora , Obesidade/dietoterapia , Sobrepeso/dietoterapiaRESUMO
Our aim is to analyse the differences in the prevalence of premenstrual asthma (PMA) according to a set of criteria, the relationship between them and the influence of asthma severity. The answer "Yes" to "Does your asthma get worse before menstruation?" was considered subjective PMA. A daily respiratory symptoms register of fertile asthmatic females was taken during two consecutive menstrual cycles. For the semi-objective diagnosis, an exacerbation of > or =20% was required in the symptoms register. Objective diagnosis was a premenstrual worsening of > or =20% of peak flow. We selected 103 patients. Subjective premenstrual deterioration was perceived in 43.7%. The semi-objective deterioration of symptoms in the first cycle occurred in 44.7%, and in 22.3% in both cycles. A total of 54.3% of females with semi-objective criteria in the first cycle perceived a subjective deterioration of symptoms, versus 35.1% of those without semi-objective criteria (p = 0.05). PMA was present at all levels of asthma severity, with no clear link to the degree of severity. The detection of PMA prevalence, the subjective perception of this deterioration and its presence at all levels of asthma severity lead us to urge research into possible premenstrual deterioration in all fertile asthmatic females.
Assuntos
Asma/epidemiologia , Ciclo Menstrual/fisiologia , Adolescente , Adulto , Distribuição de Qui-Quadrado , Feminino , Humanos , Pessoa de Meia-Idade , Pico do Fluxo Expiratório , Prevalência , Espanha/epidemiologia , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: To assess the relationship between life styles and eating habits with the overweight and obesity prevalence in a Spanish adult population. METHODS: A population-based, cross-sectional study conducted on 2640 subjects older than 15 years, in Cádiz (Spain). Surveys were conducted in subjects' homes to obtain life styles, eating habits, and anthropometric data. Logistic regression has been used to study the association between the life style variables and overweight and obesity. RESULTS: Prevalence of overweight and obesity in Cadiz is 37% and 17%, respectively; higher in males and increases with age. BMI has an inverse relationship with educational level (PR = 2.3, 1.57-2.38). The highest levels of obesity are associated with daily alcohol consumption (PR = 1.39, 1.29-1.50), greater consumption of television,and sedentary pursuit (PR 1.5, 1.07-1.24). A lower prevalence of obesity is observed among those with active physical activity (10.9% vs 21.6%), with differences between sex. Following a slimming diet is more frequent in the obese and in women but dedicate more hours than men to passive activities. In men is greater the consumption of alcohol, high energy foods and snacks. Overweight and obesity is associated with the male sex (OR = 3.35 2.75-4.07), high consumption of alcohol (OR = 1.38 1.03-1.86) and watching television (OR = 1.52 1.11-2.07), and foods likes bread and cereals (OR = 1.47 1.13-1.91). Exercise activities is a protective factor (OR = 0.76 0.63-0.98). CONCLUSIONS: Life styles factors associated with overweight and obesity present different patterns in men and women and is necessary to understand them to identify areas for behavioural intervention in overweight and obesity patients.
Assuntos
Estilo de Vida , Sobrepeso/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Prevalência , Espanha/epidemiologia , Adulto JovemRESUMO
The Tinto and Odiel rivers are heavily affected by acid mine drainage from mining areas in the Iberian Pyrite Belt. In this work we have conducted a study along these rivers where surface water samples have been collected. Field measurements, total dissolved metals and Fe and inorganic As speciation analysis were performed. The average total concentration of As in the Tinto river (1975 microg L(-1)) is larger than in the Odiel river (441 microg L(-1)); however, the mean concentration of As(III) is almost four times higher in the Odiel. In wet seasons the mean pH levels of both rivers (2.4 and 3.2 for the Tinto and Odiel, respectively) increase slightly and the amount of dissolved total arsenic tend to decrease, while the As(III)/(V) ratio strongly increase. Besides, the concentration of the reduced As species increase along the water course. As a result, As(III)/(V) ratio can be up to 100 times higher in the lower part of the basins. An estimation of the As(III) load transported by both rivers into the Atlantic Ocean has been performed, resulting in about 60 kg yr(-1) and 2.7t yr(-1) by the Tinto and Odiel rivers, respectively.
Assuntos
Arsênio/análise , Monitoramento Ambiental/métodos , Resíduos Industriais/análise , Ferro , Mineração , Sulfetos , Poluentes Químicos da Água/análise , Ácidos , Arsenicais/análise , Clima , Ferro/análise , Rios , Estações do Ano , Espanha , Movimentos da ÁguaRESUMO
The increasing CO(2) concentration in the Earth's atmosphere, mainly caused by fossil fuel combustion, has led to concerns about global warming. A technology that could possibly contribute to reducing carbon dioxide emissions is the in-situ mineral sequestration (long term geological storage) or the ex-situ mineral sequestration (controlled industrial reactors) of CO(2). In the present study, we propose to use coal combustion fly-ash, an industrial waste that contains about 4.1 wt.% of lime (CaO), to sequester carbon dioxide by aqueous carbonation. The carbonation reaction was carried out in two successive chemical reactions, first, the irreversible hydration of lime. second, the spontaneous carbonation of calcium hydroxide suspension. A significant CaO-CaCO(3) chemical transformation (approximately 82% of carbonation efficiency) was estimated by pressure-mass balance after 2h of reaction at 30 degrees C. In addition, the qualitative comparison of X-ray diffraction spectra for reactants and products revealed a complete CaO-CaCO(3) conversion. The carbonation efficiency of CaO was independent on the initial pressure of CO(2) (10, 20, 30 and 40 bar) and it was not significantly affected by reaction temperature (room temperature "20-25", 30 and 60 degrees C) and by fly-ash dose (50, 100, 150 g). The kinetic data demonstrated that the initial rate of CO(2) transfer was enhanced by carbonation process for our experiments. The precipitate calcium carbonate was characterized by isolated micrometric particles and micrometric agglomerates of calcite (SEM observations). Finally, the geochemical modelling using PHREEQC software indicated that the final solutions (i.e. after reaction) are supersaturated with respect to calcium carbonate (0.7 < or = saturation index < or = 1.1). This experimental study demonstrates that 1 ton of fly-ash could sequester up to 26 kg of CO(2), i.e. 38.18 ton of fly-ash per ton of CO(2) sequestered. This confirms the possibility to use this alkaline residue for CO(2) mitigation.
Assuntos
Dióxido de Carbono/química , Carbono/química , Material Particulado/química , Carbonato de Cálcio/química , Hidróxido de Cálcio/química , Técnicas de Química Analítica/métodos , Cinza de Carvão , Desenho de Equipamento , Cinética , Microscopia Eletrônica de Varredura , Modelos Químicos , Selenito de Sódio/química , Temperatura , Fatores de Tempo , Água/química , Difração de Raios XRESUMO
Rodlet cells are an enigmatic cell type described in tissues of both marine and freshwater teleosts. Although their structure is well established, up to date their function remains subject of debate. However, there is consensus among the majority of researchers that rodlet cells play an important role within immune system, and this function is probably related with the release of rodlets due to contractile capability of their fibrous layer. Regulation of the contraction mechanism would require proteins that modulate Ca(++) intracellular concentration to be expressed in rodlet cells. We performed a morphological and immunohistochemical study at light and electron microscopy levels to assess S100 protein immunoreactivity in developing rodlet cells. Immature stages did not exhibit immunoreactive signal; however, immunoreactivity was observed in the fibrous layer of both transitional and mature rodlet cells. The latter stage also showed immunosignal within the rodlets. These findings suggest a clear association between S100 protein expression and rodlet cell development that could be linked to the regulation of rodlet activity and contractile property of their fibrous layer. Furthermore, S100 protein antibody constitutes a novel marker for rodlet cells that could be used in future studies of this particular cell type.
Assuntos
Células Epiteliais/citologia , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Linguados/crescimento & desenvolvimento , Linguados/metabolismo , Intestinos/citologia , Proteínas S100/metabolismo , Animais , Diferenciação Celular , Sistema Imunitário/citologia , Imuno-Histoquímica , Microscopia Eletrônica de Transmissão , Proteínas S100/imunologiaRESUMO
Toxoplasmosis is one of the more common parasitic zoonoses world-wide. In this study, an epizootic of toxoplasmosis among captive Bennett's wallabies (Macropus rufogriseus) from different locations is reported. By means of light microscopy, Toxoplasma gondii-like tachyzoites were observed associated to interstitial pneumonia, non-suppurative myocarditis, cholangiohepatitis and severe gastroenteritis. The protozoa stained positively with a T. gondii antibody and ultrastructurally were similar to T. gondii. Strikingly, tachyzoites appeared sometimes in an intranuclear location within granulocyte-like cells. Feral cats or reactivation of a latent infection are discussed as the possible sources of infection. As far as we know, this is the first confirmed report of toxoplasmosis in Bennett's wallabies in Spain and Europe, and may constitute a risk of infection for humans since new alimentary habits are being imposed in our countries.