First Record of Malformation in Seahorses Attributed to the Oil Spill off the Brazilian Coast in 2019.

In 2019, there was an environmental catastrophe in Brazil, when more than 5000 tons of unknown origin crude oil invaded beaches and mangroves. Two years later, two monitoring areas were selected to study seahorses' offspring: Massangana River estuary (apparently healthy area) and Cocaia Island (affected area). Thirty-six reproductive events of Hippocampus reidi (Syngnathidae) couples from these two areas were monitored to analyze the offspring. At the apparently healthy area, no newborns with malformations were found. However, the offspring from Cocaia Island showed a mean of 19.73% (±5.23) malformations in newborns. It is argued that the toxic/teratogenic effects of polycyclic aromatic hydrocarbons have affected the population in two ways: directly through the induction of mutations in the germ cells of the species and through a drastic reduction of the population (bottleneck effect) whose density observed today recovered through consanguineous couplings, potentiating deleterious genotypes in the offspring. Environ Toxicol Chem 2024;43:1996-2004. © 2024 SETAC.

Mining tailings alter insects: revealing fluctuating asymmetry in the caddisfly Smicridea coronata.

The Samarco/Vale/BHP mine tailing dam breach that took place in Minas Gerais, southeastern Brazil, in 2015, deposited high concentrations of metals and metalloids in the Rio Doce basin, severely impacting freshwater and riverine forest ecosystems. To assess developmental instability of caddisflies in response to the environmental impacts of the dam breach, we investigated the fluctuating asymmetry (FA) in the species Smicridea (Rhyacophylax) coronata (Trichoptera: Hydropsychidae). FA was assessed at individual and populational scales using geometric morphometric methods in the cephalic capsule and mandibles of larvae and also on the forewings of adults, both collected under the impacted condition, and under the least disturbed condition. The levels of FA increased in response to stressors on the forewings at the populational scale, and on the mandibles, at individual scale. These morphological variations in the larval and adult stages may lead to detrimental effects and result in high mortality rates as well as lower adult fitness. Trichoptera forewings are revealed as suitable traits for assessing FA, holding potential for applications in biomonitoring programs. Directional asymmetry levels were higher than FA levels for all traits, and this correlation could be explained by a transition from fluctuating to directional asymmetry in the presence of heightened disturbance. Our results validate the relationship between the impacts from the dam breach and increased developmental instability in this species with likely cascade effects on the insect community.

Association between urinary concentrations of toxic metals/metalloids and oxidative stress in Brazilians living in areas affected by the Fundão dam failure.

The Fundão Dam failure has been the most significant environmental disaster in Brazil. The catastrophe released large amounts of mining waste into the environment, including toxic metals/metalloids, which are recognized to induce carcinogenic effects. The urinary levels of 8-hydroxy-2'-deoxyguanosine (8OHdG), a widely accepted oxidative stress and carcinogenesis biomarker, provide a potential tool for assessing the disaster's health implications. This study investigated the association between urinary levels of some toxic metals/metalloids and 8OHdG in Brazilian individuals living in areas affected by the Fundão dam failure. Urinary concentrations of arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), and lead (Pb) were determined using inductively coupled plasma mass spectrometry, while 8OHdG was analyzed by liquid chromatography-tandem mass spectrometry. Non-parametric bootstrap regression was used to estimate the associations between the urinary levels of toxic elements and 8OHdG. The results showed that except for Hg, urinary concentrations of all metals/metalloids analyzed here exceeded the reference ranges for the Brazilian population. The regression analysis revealed that As (0.337; CI 95%: 0.203; 0.474), Cd (0.268; CI 95%: 0.036; 0.520), and Ni (0.296; CI 950.108; 0.469) were positively associated with creatinine-adjusted urinary 8OHdG levels. Associations were not found for Hg (0.0122; CI 95%: -0.155; 0.183) and Pb (0.201; CI 95%: -0.040; 0.498). The current findings suggest that high exposure to toxic metals/metalloids might increase 8OHdG levels with potential adverse health effects. This study is the first one in which the relationship between toxic metals/metalloids and oxidative stress biomarkers is investigated in populations affected by environmental disasters. Further prospective studies are necessary to monitor exposure levels and explore additional health impacts.

Corrigendum: Methylmercury impact on adult neurogenesis: is the worst yet to come from recent Brazilian environmental disasters?

[This corrects the article DOI: 10.3389/fnagi.2020.591601.].

Trace metal concentration along the Brazilian coast: An assessment of the influence of the Doce River plume.

The Fundão Dam rupture released tons of iron ore tailings into the environment. This study analyzes the long-term impacts and provides a possible scenario of Doce River (DR) plume dispersion. For this, water and surface sediment were collected in November 2019 along three Brazilian states to determine metal concentrations and δ13C and δ15N compositions. The δ13Csediment values of the DR plume showed a dispersion pattern mainly to the north but also in areas closer to the south of the DR mouth. Furthermore, the most negative values of δ13C and δ15N were observed in mud, followed by suspended particulate matter, sediment and the dissolved fraction, indicating that geological matrices are involved in the transport of organic matter coupled to metals to the ocean and pointing to the DR as the main source of metals in the region. Thus, this study highlights the need for continuous studies to monitor the environmental and biological conditions in these areas.

Desastre socioambiental de Mariana: implicações nas condições de saúde da população atingida e no processo de trabalho dos serviços de saúde / Mariana socio-environmental disaster: implications for the health conditions of the affected population and the work process of health services

O desastre socioambiental, ocorrido em Mariana, em consequência do rompimento da barragem de Fundão da mineradora Samarco, devastou as comunidades de Bento Rodrigues e de Paracatu de Baixo provocando perdas e danos que podem se desdobrar ao longo do tempo, produzindo efeitos profundos na saúde, no meio ambiente, bem como no contexto de vida e trabalho. Com isso, busca-se analisar o processo saúde-doença e o processo de trabalho nos serviços de saúde destinados à população atingida pelo desastre socioambiental em Mariana. Trata-se de um estudo de caso conduzido pela abordagem qualitativa, descritiva e exploratória, cujo cenário é Mariana, onde se encontram as comunidades diretamente atingidas pelo rompimento da barragem de rejeito de mineração. As fontes de evidências utilizadas foram documentos de domínio público e entrevistas com profissionais de saúde e gestores. Foram escolhidas intencionalmente a Unidade de Saúde de Bento Rodrigues e o dispositivo Conviver, por atenderem exclusivamente as famílias vítimas do desastre. Participaram da pesquisa onze profissionais de saúde e três gestores. Os dados foram analisados por meio da estratégia de proposições teóricas à luz da teoria de Determinação Social do Processo Saúde-Doença. Os resultados revelaram as implicações do desastre nas condições sociais, econômicas, culturais e sobretudo na saúde da população atingida, com consequências relacionadas aos agravos respiratórios e os ocasionados por veiculação hídrica ou contato com a lama toxica de rejeito, e os casos depressivos e demais transtornos psicossociais que intensificaram o sofrimento crônico da população. Já as implicações do desastre no processo de trabalho nos serviços de atendimento exclusivo aos atingidos, evidenciam uma (re)organização do sistema de saúde, o qual enfrentou dificuldades estruturais tanto na fase emergencial quanto de recuperação pós-desastre. Destaca-se que embora os instrumentos do processo de trabalho utilizados pelos profissionais de saúde e gestores, são capazes de acolher, estimular práticas mais integradas e que transcendem a intervenção apenas nos corpos biológicos, ainda assim não são capazes de suprir as necessidades mediadas de saúde dos atingidos, não promovendo respostas às necessidades políticas, sociais e econômicas no que tange à reparação, à indenização e os direitos da população atingida.

The socio-environmental disaster that occurred in Mariana, because of the collapse of the Samarco mining company's Fundão dam, devastated the communities of Bento Rodrigues and Paracatu de Baixo, causing losses and damages that can unfold over time, producing profound effects on health, in the environment, as well as in the context of life and work. With this, we seek to analyze the health-disease process and the work process in health services intended for the population affected by the socio-environmental disaster in Mariana. This is a case study conducted using a qualitative, descriptive and exploratory approach, whose setting is Mariana, where the communities directly affected by the collapse of the mining tailings dam are located. The sources of evidence used were public domain documents and interviews with health professionals and managers. The Bento Rodrigues Health Unit and the Conviver device were intentionally chosen, as they exclusively serve families who were victims of the disaster. Eleven health professionals and three managers participated in the research. The data were analyzed using the strategy of theoretical propositions in light of the theory of Social Determination of the HealthDisease Process. The results revealed the implications of the disaster on social, economic, cultural conditions and above all on the health of the affected population, with consequences related to respiratory problems and those caused by water transport or contact with toxic waste sludge, and depressive cases and other disorders, psychosocial problems that intensified the chronic suffering of the population. The implications of the disaster on the work process in services providing exclusive care to those affected highlight a (re) organization of the health system, which faced structural difficulties in both the emergency and postdisaster recovery phases. It is noteworthy that although the work process instruments used by health professionals and managers are capable of welcoming and stimulating more integrated practices, that transcend intervention only in biological bodies, they are still not capable of meeting mediated health needs of those affected, failing to promote responses to political, social and economic needs in terms of reparation, compensation and the rights of the affected population.

Why is Brachiaria decumbens Stapf. a common species in the mining tailings of the Fundão dam in Minas Gerais, Brazil?

Currently, more than five years after the Fundão dam failure in Mariana, Minas Gerais, Brazil, Brachiaria decumbens Stapf. is the main grass in pasturelands affected by the mining tailings. The aim of this study was to investigate the reason for this fact as well as to determine the ecophysiological effects of mining tailings on B. decumbens and to test whether mixing the tailings with unaffected local soil enhances the affected soil properties. For the experiment, two different soils were collected, one unaffected soil without mining tailings (Ref) and the mining tailings (Tec), and we also created a mixture with 50 % of each soil type (Ref/Tec). We cultivated B. decumbens in the three soil treatments in a greenhouse for 110 days and evaluated soil physical-chemical properties and plant ecophysiology. Our results show that the tailings (Tec) compromised the normal ecophysiological state of B. decumbens. The species survived these adverse conditions due to its great efficiency in acquiring some elements. The soil management tested by this work mitigated the stress caused by tailings and can represent an alternative for the environmental recovery of the affected soils.

Do metals differentiate zooplankton communities in shallow and deep lakes affected by mining tailings? The case of the Fundão dam failure (Brazil).

The effects of exposure to mining tailings on water quality and biota of tropical lacustrine ecosystems remain poorly understood. We tested the hypothesis that after mining tailing spills, shallow lakes should retain higher metal concentrations in comparison with deep lakes, which might contribute to differentiating species sorting and community structure of zooplankton in both ecosystems. Surveys were performed in 6 Brazilian lakes affected by the Fundão dam failure from October 2018 to September 2019. The shallow lakes showed higher values of turbidity (19.4 ± 12.9 NTU), conductivity (846.5 ± 1727.1 µS.cm-1), total organic carbon (11.6 ± 4.6 mg.L-1), total nitrogen (2688.7 ± 2215.6 µg.L-1), iron (2507.5 ± 726.9 µg.L-1), aluminum (419.9 ± 166.5 µg.L-1) and manganese (150.8 ± 146.2 µg.L-1) and lower zooplankton richness (9.2 ± 3.2) compared to the deep lakes (13.4 ± 3.0), which showed higher cyanobacteria density (84.7 103 ± 69.3 103 cel.mL-1). We recorded negative relationships between zooplankton richness and turbidity, conductivity, iron, zinc and vanadium, indicating that as well as morphometric characteristics of lakes (area and depth) have an important role in zooplankton richness, the coupling between metals and limnological variables represent decisive environmental filters for species sorting of zooplankton. The variation-partitioning analysis showed that limnological variables and metals explained zooplankton composition, highlighting that metals play major influence on zooplankton composition. We suggest that the shallowness of the lakes should had promoted often resuspension of mining tailings that caused increases in metal concentrations in water column. The results indicate that the shallow lakes presented higher vulnerability to mining tailings exposure than the deep lakes, which may have substantially contributed for differentiating zooplankton communities in both ecosystems. This study reveals the need for considering shallow lakes as priority target for conservation among freshwater ecosystems affected by mining tailings.

Seasonality effects on the metal concentration and biochemical changes in Astyanax lacustris (Teleostei: Characiformes) from Doce River after the collapse of the Fundão dam in Mariana, Brazil.

This study aimed to evaluate the harmful effects of metal accumulation on Astyanax lacustris and their biochemical response when exposed to the metals contained in the Doce River water, Brazil. The study was carried out in the Baixo Guandu region of the Doce River, Espírito Santo state. Samples were collected during the dry and wet seasons. Biochemical alterations were observed in the liver of A. lacustris, with apparent seasonal effects directly related to the high concentration of Al and Fe in this tissue. Despite this, the bioconcentration of metals in the organisms showed seasonal effects only in the gills, as they are the first organ in contact with the contaminated water. The data generated in this study provide an overview of the health of the ecosystem in this region, highlighting the harmful biochemical and metal concentration effects on the population of A. lacustris affected by the Fundão dam failure.

Application of remote sensing in environmental impact assessment: a case study of dam rupture in Brumadinho, Minas Gerais, Brazil.

The collapse of mining tailing dams in Brumadinho, Minas Gerais, Brazil, that occurred in 2019 was one of the worst environmental and social disasters witnessed in the country. In this sense, monitoring any impacted areas both before and after the disaster is crucial to understand the actual scenario and problems of disaster management and environmental impact assessment. In order to find answers to that problem, the aim of this study was to identify and analyze the spatiality of the impacted area by rupture of the tailing dam of the Córrego do Feijão mine in Brumadinho, Minas Gerais, by using orbital remote sensing. Land use and land occupation, phytoplankton chlorophyll-a, water turbidity, total suspended solids on water, and carbon sequestration efficiency by vegetation (CO2Flux) were estimated by orbital imagery from the Landsat-8/OLI and MSI/Sentinel-2 sensors in order to assess the environmental impacts generated by the disaster. Data were extracted from spectral models in which the variables that best demonstrated the land use variation over the years were sought. Mean comparison by t-test was performed to compare the time series analyzed, that is, before and after the disaster. Through the analysis of water quality, it was observed that the environmental impact was calamitous to natural resources, especially water from Córrego do Feijão.

Iron ore tailings as a source of nutrients to the coastal zone.

The Fundão dam rupture was one of the largest environmental disasters worldwide and released millions of m3 of iron ore tailings into the Doce River basin in southeastern Brazil. Here we assessed the supply of dissolved nutrients associated to tailings in the Doce River estuary and its adjacent coastal zone. First, we observed an acute increase in dissolved silicates (From 16.26 µM to 175.47 µM) and nitrate (From 5.56 µM to 50.69 µM) in the estuary when compared to days prior to the event. Coastal marine ecosystems showed significant concentrations of nitrite (From 0.72 µM to 2.99 µM) and phosphate (From 0.09 µM to 2.30 µM) one year after the disaster, which we attribute mainly to nutrient recycling. The chronic effects include an increase in nutrient load to the coastal zone with a predominance of nitrogenous species, which may increase the limitation of phosphorus and silica to marine primary production.

Spectro-temporal analysis of the Paraopeba River water after the tailings dam burst of the Córrego do Feijão mine, in Brumadinho, Brazil.

Remote sensing is an important tool for environmental assessment, especially in the event of disasters such as the tailings dam burst at the Córrego do Feijão mine, located in the Paraopeba River basin, Brazil. Thus, this study aimed to carry out a spectro-temporal analysis of the Paraopeba River water given the dam burst, using multispectral images from the MSI sensor onboard Sentinel-2 satellites. For this analysis, sections along the river were defined by the creation of buffers, with 10-km intervals each, starting from the origin of the burst. For each section, the average visible to near-infrared (NIR) reflectance values per band and the Normalized Difference Water Index (NDWI) were obtained. We found that the red edge and NIR bands (B5, B6, B7, B8, and B8A) showed higher reflectance values when compared to the visible bands in the months immediately after the disaster, especially in the first 20 km. In these months, negative NDWI values were also found for almost all sections downstream, demonstrating the large volume of mining tailings in the Paraopeba River. The seasonal variation of the observed values indicates the resuspension of the material deposited at the river bottom with the beginning of the rainy season. Finally, we highlight the usefulness of the MSI/Sentinel-2 red edge and NIR bands for further studies on the monitoring from space of water bodies subjected to contamination by large amounts of mud with iron ore tailings and contaminants, as occurred in the state of Minas Gerais, southeastern Brazil.

Hydraulic and auto-depurative characteristics of the Gualaxo do Norte River after the Fundão dam rupture.

The hydraulic characteristics of the Gualaxo do Norte River (RGN), a tributary of the upper Rio Doce basin, were affected in November 2015 by the rupture of the iron ore tailings dam at Fundão, in Bento Rodrigues, Mariana, Minas Gerais. We analyzed two sections of the RGN, located upstream and downstream of the Fundão dam. Measurements were taken at 11 stations along the main river in distinct seasonal periods, including river depth, river width, velocity, and flow. We also calculated the deoxygenation coefficient (K1) and the reaeration coefficient (K2) and collected elaborate bathymetric profiles of the sections. Anthropogenic interference influenced the river's hydraulic characteristics mainly in relation to the depth. In upstream sections, the changes are believed to be due to mining activities at the head of the river, while downstream effects were due to the introduction of iron ore tailings coming from the rupture of the Fundão dam. Despite these influences, deoxygenation coefficient values were typical for clean water, and the reaeration coefficient findings show that the RGN is efficient at biological degradation of the organic matter even receiving untreated domestic sewage from riparian communities. With the results obtained in this work, we seek to replicate a source of information about the current state of the region and to contribute information to future river planning, control, and restoration projects.

Immediate effects of the 2019 oil spill on the macrobenthic fauna associated with macroalgae on the tropical coast of Brazil.

The 2019-2020 Brazil oil spill disaster affected several ecosystems and species-rich areas. The shallow-water reefs of Paiva beach are among the best-preserved coastal environments in the State of Pernambuco (NE Brazil), but were severely affected by oil arrival at the end of 2019. The reefs are densely covered by macroalgae as important biogenic substrates for benthic fauna. Based on that, herein, we provide a baseline assessment of the immediate impacts of the oil spill on the structure of epifaunal communities associated with the algae Jania capillacea and Penicillus capitatus. The benthic communities in both algae simplified (reduction of species richness and abundance) soon after oil arrival, while opportunistic taxa increased. After two months, the macrofaunal communities restructured to almost pre-disaster levels. However, polychaeta diversity remained low. Despite the apparently fast recovery of reef macrobenthos, a more detailed, long-term monitoring is necessary to evaluate the chronic effects.

Trace metals in Rio Doce sediments before and after the collapse of the Fundão iron ore tailing dam, Southeastern Brazil.

The collapse of the Fundão Dam, in Southeastern Brazil, caused about 50 million m³ of iron ore tailings to sluice down the mountain to Rio Doce, in what is considered the greatest environmental disaster in Brazilian history. The fluvial system received an intense and sudden mudflow that was transported for more than 650 km, before reaching the Atlantic Ocean. Because the area was already impacted by the mineral activities in the region, it becomes essential to evaluate the environmental conditions before the disaster to correctly assess the disaster real damage. This study compares the concentration of trace metals in the sediments of the Rio Doce alluvial plain, before and after the dam collapse, as well as the newly deposited iron ore tailings that became part of the sedimentary framework. The data indicate that the fine particles deposited have since been incorporated into the sandy river sediments. The cadmium and arsenic contents in the sediments increased to levels above the National Environment Council thresholds. The comparison between the levels of trace metals in the situations before and after disaster shows that the mining mud is the source of cadmium while the arsenic was present before the environmental disaster, and its concentration increased due to sediment remobilization. The iron ore tailings deposited on the alluvial sediments also affected the physical parameters since the formed ferruginous crusts waterproofed the ground surface and may, gradually, release toxic metals when exposed to weathering and river reworking.

Methylmercury Impact on Adult Neurogenesis: Is the Worst Yet to Come From Recent Brazilian Environmental Disasters?

Worldwide environmental tragedies of anthropogenic origin causing massive release of metals and other pollutants have been increasing considerably. These pollution outbreaks affect the ecosystems and impact human health. Among those tragedies, recent large-scale environmental disasters in Brazil strongly affected riverside populations, leading to high-risk exposure to methylmercury (MeHg). MeHg is highly neurotoxic to the developing brain. This toxicant causes neural stem cell dysfunction and neurodevelopmental abnormalities. However, less is known about the effects of MeHg in the postnatal neurogenic niche, which harbors neural stem cells and their progeny, in the adult brain. Therefore, taking in consideration the impact of MeHg in human health it is urgent to clarify possible associations between exposure to mercury, accelerated cognitive decline, and neurodegenerative diseases. In this perspectives paper, we discuss the neurotoxic mechanisms of MeHg on postnatal neurogenesis and the putative implications associated with accelerated brain aging and early-onset cognitive decline in populations highly exposed to this environmental neurotoxicant.

(Ir)responsabilidade social empresarial: uma avaliação do desastre de Mariana-MG / (Ir)responsabilidad social empresarial: evaluación del desastre de Mariana-MG / Corporate social (ir)responsibility: an analysis of the disaster in Mariana-Brazil

Resumo A temática irresponsabilidade social empresarial (IrSE) ganhou destaque na literatura mundial. No Brasil, o desastre causado pela Samarco Mineração S.A. em 2015 foi alvo de repercussão, constituindo uma oportunidade para estudar a IrSE. O objetivo deste estudo foi investigar se a identificação social com a empresa, que surge em função dos benefícios econômicos, reduz a intenção punitiva e a atribuição de culpa. O instrumento de pesquisa contém escalas com indicadores psicométricos aplicados a 1.616 indivíduos. Constatou-se que os benefícios para a economia local reduziram a intenção punitiva nas cidades de Anchieta-ES, Guarapari-ES e Mariana-MG. O que não ocorreu nas cidades de Colatina-ES e Linhares-ES, que não recebem benefícios econômicos, mas foram afetadas pelo desastre. Identificou-se, ainda, que a severidade do evento aumentou a atribuição de culpa e a intenção punitiva aumentou a intenção de comentários negativos. Como principal conclusão, onde a empresa gerou benefícios, as pessoas estavam menos propensas a puni-la.

Resumen La temática irresponsabilidad social empresarial (IrSE) ganó prominencia en la literatura mundial. En Brasil, el desastre causado por Samarco Mineração S.A. en 2015 fue objeto de repercusión, constituyendo una oportunidad para estudiar la IrSE. El objetivo de este estudio fue investigar si la identificación social con la empresa, que surge en función de los beneficios económicos, reduce la intención punitiva y la atribución de culpa. El instrumento de investigación contiene escalas con indicadores psicométricos aplicados a 1.616 individuos. Se constató que los beneficios para la economía local redujeron la intención punitiva en las ciudades de Anchieta, ES; Guarapari, ES y Mariana, MG. Lo que no ocurrió en las ciudades de Colatina, ES y Linhares-ES, que no reciben beneficios económicos y fueron afectadas por el desastre. Se identificó además que la severidad del acontecimiento aumentó la atribución de culpa y la intención punitiva aumentó la intención de comentarios negativos. Como conclusión, donde la empresa generó beneficios, la gente estaba menos propensa a castigarla.

Abstract The issue of corporate social irresponsibility (CSIR) has gained prominence in world literature. This study analyzes the 2015 environmental disaster caused by Samarco Mineração S.A. in Mariana (MG), Brazil, as an example of CSIR. The objective was to understand whether the population's social identification with the company, which is translated into the economic benefits, reduced punitive intention, and blame attribution. The research instrument uses scales with psychometric indicators applied to 1,616 individuals. It was verified that the benefits to the local economy reduced the punitive intention in the municipalities of Anchieta and Guarapari (ES), and Mariana (MG). This was not the case for Colatina and Linhares (ES). Also, it was observed that the disaster's severity increased blame attribution, and the punitive intention increased the intention to engage in negative word-of-mouth (WOM) about the company. As the main conclusion, people were less likely to punish the company in the municipalities where it generated economic benefits.

Is the Doce River elutriate or its water toxic to Astyanax lacustris (Teleostei: Characidae) three years after the Samarco mining dam collapse?

In 2015, after the Fundão dam failure, in Minas Gerais State, Brazil, around 50 million cubic meters of sludge from iron mining tailings were discharged into the Doce River. After the dam collapse, surpassing concentrations of metals were observed in the river sediment, which could be harmful to aquatic organisms, including the fishes. The present study aimed to evaluate the toxic effects of both elutriate and water, collected from the Doce River, on Astyanax lacustris three years after the dam failure. A bioassay was carried out through subchronic exposure to Doce River water (E0) and three elutriate concentrations (10, 50 and 100%). Biochemical analyses (CAT, GST, AChE), metal bioaccumulation assays and calculation of the integrated biomarker response index, version 2 (IBRv2) were performed. The outcomes uncovered deleterious consequences on organisms exposed to E0, with AChE inhibition and bioaccumulation of Fe and Mn in both liver and gills. IBRv2 values were more elevated in fishes exposed to E0 for all tissues. Thus, the elutriate was not harmful for the assessed fishes, since complexing agents presented in the sediment, such as goethite and hematite, may have triggered metals' chelation. In this scenario, the elutriate may have acted as a protective agent for the subjected organisms, unlike the Doce River waters, in which contaminants were proven to be hazardous for the aquatic biota.

Environmental disasters and birth outcomes: Impact of a tailings dam breakage in Brazil.

There is evidence of a relationship between in utero exposure to catastrophic events and adverse birth outcomes, usually attributed to heightened maternal stress. The objective of our work was to evaluate if the breakage of a dam containing wastefrom a mining cite in Brazil, in 2015, an environmental disaster popularly known as the Mariana Tragedy, affected the health of newborns exposed in utero. We used administrative data on birth records and reports on the Mariana Tragedy to identify all births from newborns exposed in utero and the intensity of that exposure, according to the mother's municipality of residence. Using a difference-in-differences framework, we estimated the impact of different intensities of exposure on birth outcomes. We found that being directly exposed in utero to the Tragedy resulted in 1.86 days shorter gestational age and 2.6 percentage points higher incidence of preterm birth (<37 weeks). We found no impact on birthweight related outcomes. The effect is larger than previously identified for other catastrophic events. We hypothesize that this is probably due to the Tragedy impacting birth outcomes not exclusively through heightened maternal stress, but also through depressed economic activity in directly affected municipalities.

Ecological Risks of Metal and Metalloid Contamination in the Rio Doce Estuary.

The rupture of a mining dam in southeastern Brazil in 2015 was the country's greatest environmental tragedy. In order to evaluate the ecological risks of the mine tailings on the Rio Doce estuary, this study assessed trace metal contamination and sediment quality indices up to 2.9 y after the dam rupture. Surface sediments were collected from 17 stations on the Rio Doce estuary and Cd, Pb, Cr, Zn, Cu, and As concentrations were determined by inductively coupled plasma atomic emission spectroscopy (ICP-OES). Four ecological risk indices (modified contamination degree [mCd], pollution load index [PLI], risk index [RI], and sediment quality guideline quotient [SQG-Q]) suggest a high risk by metal contamination with possible adverse biological effects, with moderate seasonal variability. Based on a precautionary approach, our results support fisheries closures and the need for public health monitoring in the affected areas, and support other studies that suggest chronic metal contamination of the Rio Doce estuary. Integr Environ Assess Manag 2020;16:655-660. © 2020 SETAC.

A ruptura de uma barragem de mineração no sudeste do Brasil em 2015 causou a maior tragédia ambiental do país. Para avaliar os riscos ecológicos dos rejeitos de minério no estuário do Rio Doce, este estudo avaliou os índices de contaminação por metais traços e qualidade dos sedimentos até 2,9 anos após a ruptura da barragem. Os sedimentos de superfície foram coletados em 17 estações no estuário do Rio Doce e as concentrações de Cd, Pb, Cr, Zn, Cu e As foram determinadas por ICP-OES. Quatro índices de risco ecológico (mCd, PLI, RI e SQG-Q) sugerem um alto risco de contaminação por metais com possíveis efeitos biológicos adversos, com variabilidade sazonal moderada. Com base em uma abordagem preventiva, nossos resultados apoiam o fechamento da pesca e a necessidade de monitoramento da saúde pública nas áreas afetadas, além de apoiar outros estudos que sugerem contaminação crônica por metais no estuário do Rio Doce. Integr Environ Assess Manag 2020;16:655-660.