RESUMEN
The rupture of the Fundão mine dam in Mariana municipality, Minas Gerais State, Brazil, spilled the tailings across the Doce River basin. These tailings, composed of residues discarded from the beneficiation of iron ore, are rich in SiO and AlO, as well as some ether amine compounds and NaOH. The aim of this study was to assess the distribution of these sediments, as well as their effect on the riparian zones reached, as compared with preserved sites. Sediment deposition in the river resulted in a morphological change from a meandering profile to a braided aspect. The nutrient and mineral content (P, K, Ca, Mg, Cu, Fe, Mn, Zn, and NO) and soil organic matter of the sediments were depleted, whereas NH, Na, and pH increased. A random presence of ether amines in the sediments was confirmed by quantitative and chromatographic analyses, with concentrations ranging from 0 to 57.8 mg kg; Na reached values as high as 150 mg kg. The impact of the dam tailings on biota was assessed by estimating total microbial biomass (phospholipid fatty acids), which were depleted in sediments relative to soils from preserved sites. Overall plant mortality, as well as a low resilience capacity, were also observed. Ether amines and Na present in the sediments had a strong toxic effect in the environment. Identification of these substances as the main impact factors will help guide future remediation efforts.
Asunto(s)
Liberación de Peligros Químicos , Restauración y Remediación Ambiental/métodos , Residuos Industriales , Minería , Brasil , Medición de Riesgo , Ríos/química , Suelo/químicaRESUMEN
The objective of the present work is to compare two methodologies based on multicriteria analysis for the evaluation of stormwater systems. The first methodology was developed in Brazil and is based on performance-cost analysis, the second one is ELECTRE III. Both methodologies were applied to a case study. Sensitivity and robustness analyses were then carried out. These analyses demonstrate that both methodologies have equivalent results, and present low sensitivity and high robustness. These results prove that the Brazilian methodology is consistent and can be used safely in order to select a good solution or a small set of good solutions that could be compared with more detailed methods afterwards.
Asunto(s)
Ciudades , Drenaje de Agua/métodos , Brasil , Medio Social , Movimientos del Agua , Abastecimiento de AguaRESUMEN
The need for a reliable method for the immunological diagnosis of kala-azar is imperative. Leishmania donovani donovani and L. donovani chagasi culture promastigotes were compared as antigens in a direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis in Brazil. Both antigens were successfully employed for the DAT, showing 100% sensitivity and greater than 98% specificity when used to test sera from Brazilian and African kala-azar, Chagas' disease, malaria, filaria and syphilis patients, and on sera from Brazilian controls. Cross-reactions were sometimes observed when cutaneous and mucocutaneous leishmaniasis patient sera were tested. The cross-reactions were completely abolished by the addition of 0.78% 2-mercaptoethanol to the serum diluent. These data show that this improved DAT can be used for the diagnosis of visceral leishmaniasis in Brazil.
Asunto(s)
Pruebas de Aglutinación , Antígenos de Protozoos/análisis , Leishmania donovani/inmunología , Leishmaniasis Visceral/diagnóstico , Animales , HumanosRESUMEN
The need for a reliable method for the immunological diagnosis of Kala-azar is imperative. Leishmania donovani donovani and L. donovani chagasi culture promastigotes were compared as antigens in a direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis in Brazil. Both antigens were successfully employed for the DAT, Showing 100½ sensitivity and > 98% specificity when used to test sera from Brasilian and African Kala-azar, Chagas'disease, malaria, filaria and symphilis patients, and on sera from Brazilian controls. Cross-reactions were sometimes observed when cutaneous and cucocutaneous leishmaniasis patient sera were teste. The vross-reactions were completely abolished by the addition of 0.78% 2-mercaptoethanol to the serum diluent. These data show data that this improved Dat can be used for the diagnosis of visceral leishmaniasis in Brazil