Analyses of colloidal, truly dissolved, and DGT-labile metal species and phosphorus in mining area surrounded by tailing dams using self-organising maps.

The knowledge of size-distribution and lability of metals and nutrients in freshwater systems is important for estimation of the ecological effects of mining. However, it is still limited in several mining areas such as the Quadrilátero Ferrífero (Brazil) which was severely polluted by the collapse of the Fundão tailings dam in November 2015. In this study, results of an investigation from 2014 using a neural network named self-organising map (SO-Map) into the conditions of selected trace metals that are of particular importance to mining areas (Cr, Cu, Co, Mn, Ni, Pb, Zn) are presented. Additionally, P was considered by its high importance as a nutrient and sites later affected by the dam burst were also included by chance. Water samples were collected at six sites in dry and rainy seasons and filtered and ultrafiltered for determination of total dissolved (<0.45 µm) and truly dissolved (<1 kDa) fractions. Diffusive gradients in thin films (DGT) devices were deployed in situ for determination of the DGT-labile fraction. All data were analysed using SO-Map and Spearman's rank correlation. Phosphorus in the Carmo River occurred mainly in the truly dissolved and DGT-labile fractions. The higher amounts of this element in the river water (up to 263 µg L-1 of total P) might be related to untreated sewage discharge. Moreover, the concentrations of other trace metals (Mn, Cu, Co, Ni, Zn) were high, even under the "natural" conditions (before the dam failure) due to natural and anthropogenic factors such as local lithology and mining.

Geochemical evaluation of bottom sediments affected by historic mining and the rupture of the Fundão dam, Brazil.

The rupture of the Fundão dam released about 39 million m3 of tailings into the Rio Doce/Brazil. The sediment load increase in the affected rivers has become a concern. As such, this article provides recent information about the region. In addition, based on past studies in the region, it shows the magnitude and dynamics of the environmental impacts caused by the rupture of the dam on the bottom sediments. Sediment samples in different seasonal periods were collected at eleven sampling stations located along the Gualaxo do Norte River, the first tributary of the Rio Doce affected by the environmental disaster. These sediments underwent physical, chemical, and granulometric analyses for their organic, metal, and semimetal content. The contamination factor and the enrichment factor of the samples also were calculated. To evaluate the anthropogenic contributions to sediment metal concentrations, reference values (regional background values) for the Gualaxo do Norte River were used. The results indicate that, in the sampling stations not affected by the disaster, the concentrations of the metals and semimetals reflect the geology of the Quadrilátero Ferrífero. However, in the area affected by the environmental disaster, there were changes in the chemical and physical properties of the bottom sediment, mainly in the concentrations of iron, organic matter, and fine sediment fractions. This was reflected in the contamination factors and enrichment factors calculated for the sediments of the sampling stations. Iron and manganese concentrations in sediments are much higher than other rivers in the world that are unaffected by mining activities. The observed changes in the bottom sediments of the river suggest a need for constant monitoring of the iron because the iron oxide minerals present in silt and clay have a high adsorption capacity. In the long term, these factors may contribute to the decrease of the quality of these sediments and consequently of the waters and biota present in these environments.

Antibiotic consumption in developing countries defies global commitments: an overview on Brazilian growth in consumption.

Faster spread of epidemics has turned local concerns into global crises; antimicrobial resistance (AMR) is being considered a major threat to public health in the twenty-first century. Antibiotic misuse plays a great role in accelerated AMR; thus, understanding and discussing consumption patterns has been a trend topic over the past years. Developing countries, such as Brazil, have high growth rates in antibiotic consumption, potentially impacting global environmental safety. This study presents the compiled information from the Brazilian Health Regulatory Agency (ANVISA) on antibiotic dispensation across the country and maps the consumption trends between the years of 2013 and 2016. The most consumed substances were beta-lactams (amoxicillin and cephalexin) and macrolides (azithromycin). National relative growth consumption in the mentioned period was 18%. At the local level, growth of consumption ranged from 4 to 85%, with rampage growth concentrated in the North and Northeast regions. Brazilian laws, such as restriction of over-the-counter sales and mandatory report on dispensation, seem to have little effect on the national antibiotic consumption growth. This phenomenon growth is still elevated if compared with developed countries, demonstrating the need for further surveillance as well as coordinated efforts aiming at antibiotic use and AMR prevention.

Influence of environmental and anthropogenic factors at the bottom sediments in a Doce River tributary in Brazil.

In developing countries, it is uncommon to find watersheds that have been the object of detailed environmental studies. It makes the assessment of the magnitude of environmental impacts and pollution of these sites difficult. This research demonstrated ways to understand the dynamics of river bottom sediments contamination, even for watersheds with a lack of environmental data. Based on geochemical affinity, we conducted a comprehensive study on the concentration of metals and metalloids. Then, we discussed the probable origin of the concentration of these elements at the bottom sediment along the Matipó River. The Matipó River is an important tributary of the Doce River, which stood out in international headlines because of the mining tailing dam disaster in Mariana, Minas Gerais, in 2015. The bottom sediment samples were taken in 25 stations located along the basin in different seasonal periods. The results showed that copper ([Formula: see text] = 464.7 mg kg-1) and zinc ([Formula: see text] = 287.7 mg kg-1) probably have natural origin, despite of the high concentrations. Lead ([Formula: see text] = 28.0 mg kg-1), chromium ([Formula: see text] = 153.2 mg kg-1), and nickel ([Formula: see text] = 41.8 mg kg-1) also had high concentrations at some collecting stations, and this probably reflected the local natural conditions. The bedrock of the studying basin is dominantly composed of metabasalts and metatonalites interlayered with calcitic and dolomitic metalimestone. On the other hand, the concentration was worrisome in stations near human activities, possibly due to impacts caused by unsustainably agriculture and livestock.

Avaliação geoquímica de metais em sistemas fluviais afetados por atividades antrópicas no Quadrilátero Ferrífero / Geochemical assessment of metals in fluvial systems affected by anthropogenic activities in the Iron Quadrangle

RESUMO O presente estudo foi realizado na bacia hidrográfica do Rio do Peixe, Quadrilátero Ferrífero (QF), em Minas Gerais. Essa bacia apresenta um cenário geológico distinto e atividades antrópicas diversificadas, como a mineração de ferro, ouro e gemas, a agropecuária e a silvicultura. O principal objetivo desta pesquisa foi investigar as possíveis fontes de contribuições antropogênicas dos metais em sedimentos de fundo. Para isso, foram realizadas duas campanhas com amostragens de sedimentos de fundo em 12 pontos da bacia, nos meses de março e julho de 2015. A partir da técnica analítica de espectrometria de emissão óptica com plasma, foram detectadas concentrações de Al, Ca, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti e Zn nos sedimentos de fundo. Os resultados dos indicadores da qualidade dos sedimentos fator de contaminação (FC), fator de enriquecimento (FE) e índice de geoacumulação (IGEO) demonstraram que há interferências antrópicas, sendo as atividades minerárias e industriais, o despejo de efluentes domésticos e o uso e a ocupação do solo inapropriado apontados como as principais fontes de contaminação de metais da bacia.

ABSTRACT The present study was carried out in the river basin area of Rio do Peixe, Iron Quadrangle, in Minas Gerais, Brazil. This basin presents geological scenario and diversified anthropic activities, such as iron, gold and gems mining, agriculture, and forestry. The main objective of this research was to investigate the possible sources of anthropogenic contributions of metals in bottom sediments. Thus, two surveys were carried out on bottom sediments at twelve basin sites from March to July of 2015. Based on the plasma optical emission spectrometry analytical technique, we found concentrations of Al, Ca, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti and Zn in the bottom sediments. The results of the FC, FE and IGEO sediment quality indicators showed that there are anthropic interferences, in which mining and industrial activities, disposal of domestic effluents and use and occupation of inappropriate soil are identified as the main sources of metals contamination of the basin.

Identificação molecular de Escherichia coli diarreiogênica na Bacia Hidrográfica do Rio Xopotó na região do Alto Rio Doce / Molecular identification of diarrheagenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Brazil

RESUMO Esta pesquisa científica teve como principal objetivo identificar patótipos de Escherichia coli diarreiogênica nas águas superficiais da Bacia Hidrográfica do Rio Xopotó, na região do Alto Rio Doce, Minas Gerais. Os estudos referentes às estirpes diarreiogênicas de E. coli no meio ambiente no Brasil são escassos. A bacia hidrográfica escolhida para o estudo sofre intensa degradação ambiental devido ao lançamento de esgoto in natura em seus corpos d'água e às atividades antrópicas, como a agropecuária. As coletas de água nos 13 pontos amostrais foram realizadas em duas épocas do ano de 2015 (abril e julho). Para identificação dos genes de E. coli diarreiogênica, utilizou-se o método de reação em cadeia da polimerase (PCR). A bacia hidrográfica apresentou contaminação diarreiogênica de patótipos E. coli produtora de toxina Shiga (STEC), E. coli enteropatogênica (EPEC) e E. coli enterotoxigênica (ETEC), tal ocorrência foi constante em ambas as campanhas. Os genes de virulência observados foram: na STEC, toxina Shiga (Stx1), responsável por causar doenças renais graves, como a síndrome hemolítico-urêmica (SHU); já a EPEC apresentou somente o gene virulento eae, característico do subgrupo atípico (aEPEC); a ETEC apresentou toxinas termolábeis (LT). A presença desses patótipos representa potencial risco de doenças diarreiogênicas na população que utiliza os recursos hídricos, particularmente idosos e crianças, e evidencia o comprometimento da qualidade microbiológica dos cursos d'água constituintes da Bacia Hidrográfica do Rio Xopotó, decorrente principalmente da ausência de estações de tratamento de esgoto (ETEs).

ABSTRACT The main purpose of this scientific research was to identify pathotypes of diarrheogenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Minas Gerais region, Brazil. The studies referring to the stirps diarrheagenics of E. coli in the environment in Brazil are scarce. The watershed chosen for the study suffers intense environmental degradation due the release of raw sewage into their water bodies and human activities, such as agriculture. The water collecting at 13 sampling points were held in two periods of the year 2015 (April and July). For the identification of the genes of diarrheagenic E. coli, the method of reaction polymerase chain (PCR) was used. The watershed presented pathogenic contamination of pathotypes Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) such a constant occurrence in both campaigns. The virulence genes observed were: STEC, Shiga toxin (Stx1), responsible for causing severe kidney disease as hemolytic-uremic syndrome (HUS). Besides that, EPEC presented only the virulent gene eae, characteristic of the atypical subgroup (aEPEC), as well as thermolabile toxins (LT). The presence of these pathotypes represents potential risk of diarrheagenic diseases in the population that uses the water resources, particularly the elderly and children, and demonstrates the commitment of the microbiological quality of constituents watercourses of the watershed of Xopotó River, mainly because the lack of sewage treatment facilities.