Estresse e depressão em docentes de uma instituição pública de ensino

Objectives: To analyze the presence of stress and signs indicative of depression in teachers of a public educational institution.Materials and Methods: An analytical study was conducted with 163 teachers from a public educational institution. The Perceived Stress Scale-EEP and Beck-IDB Depression Inventory were applied.Results: Of the 163 participants, 108 (66.3%) were males, 64 (39.3%) were between 30 and 39 years of age, 79 (48.5%) had a wage income of more than 15 wages minimum, 80 (49.1%) reported brown color. The majority had a master's degree, 84 (51.5%). Minimal levels of stress were identified in men, 73 (67.0%) and 34 (63.0%) in women. 87 (79.8%) women and 35 (64.8%) men had minimal depression. There was a significant difference in the stress and depression scores between the sexes. There was a moderate positive correlation between the scales.Conclusion: Teachers with minimal and light levels are subject to stress and depression, deserving attention from the institutions.Objetivos: Analizar la presencia de estrés y signos indicativos de depresión en docentes de una institución pública de enseñanza.Material y Métodos: Estudio analítico, realizado con 163 docentes de una institución pública de enseñanza. Se aplicó Escala de estrés percibido-EEP e inventario de depresión de Beck-IDB.Resultados: De los 163 participantes, 108 (66,3%) eran del género masculino, 64 (39,3%) con rango de edad de 30 a 39 años, 79 (48,5%) tenían una renta salarial de más de 15 salarios (en el caso de las mujeres). La mayoría presentó título de maestro, 84 (51,5%). Se identificaron niveles mínimos de estrés en hombres, 73 (67,0%) y 34 (63,0%) en mujeres. 87 (79,8%) mujeres y 35 (64,8%) hombres presentaron un nivel de depresión mínima. Hubo diferencias significativas en los escores de estrés y depresión entre los sexos. Se observó una correlación positiva moderada entre las escalas.Conclusión: Los docentes con niveles mínimo y leve están sujetos a presentar estrés y depresión, mereciendo atención por parte de las instituciones.Objetivos: Analisar a presença de estresse e sinais indicativos de depressão em docentes de uma instituição pública de ensino. Material e Métodos: Estudo analítico, realizado com 163 docentes de uma instituição pública de ensino. Aplicou-se Escala de Estresse Percebido-EEP e Inventário de Depressão de Beck-IDB. Resultados: Dos 163 participantes, 108 (66,3%) eram do gênero masculino, 64 (39,3%) com faixa etária de 30 a 39 anos, 79 (48,5%) tinham uma renda salarial de mais de 15 salários mínimos, 80 (49,1%) referiram cor parda. A maioria apresentou título de mestre, 84 (51,5%). Identificaram-se níveis mínimos de estresse em homens, 73 (67,0%) e 34 (63,0%) em mulheres. 87 (79,8%) mulheres e 35 (64,8%) homens apresentaram nível de depressão mínima. Houve diferença significativa nos escores de estresse e depressão entre os sexos. Observou-se uma correlação positiva moderada entre as escalas. Conclusão: Os docentes com níveis mínimo e leve estão sujeitos a apresentarem estresse e depressão, merecendo atenção por parte das instituições

Quantification of methylmercury and geochemistry of mercury in sediments from a contaminated area of Descoberto (MG), Brazil.

In 2002, metallic Hg was found buried in a rural area of Descoberto city, Brazil. The origin of the Hg was a gold mining explotation plant established nearly one century ago. Although a number of studies have been conducted in order to assess the contamination of the area, none of them investigated the presence of methylated Hg in the hydric system. In this work methylmercury (CH3Hg?) was determined using gas chromatography-pyrolysis-atomic fluorescence detection (CG-pyro-AFS) in material from rain sedimentation boxes and stream sediments near the contaminated area. Total Hg concentration (HgT) along with the chemical speciation by thermo-desorption were performed. HgT in material from the sedimentation boxes was found to be very high, up to 41,580 mg kg 1, even in the rainy season, when in general HgT were much lower than in dry season. The samples from the Grama and Rico streams show a range of HgT from 5.8 to 266 mg kg 1. The thermo-desorption analysis showed predominance of Hg2?, possibly linked to organic sulfur, suggested by a good positive correlation between Hg2?, HgT, organic mater (OM) and total S. The CH3Hg? concentration in stream sediment samples ranged from <0.07 to 1.87 mg kg 1 and in the samples of sedimentation boxes the concentrations were 1.33 and 8.0 mg kg 1 during dry season. The sample with the highest percentage of HgT as Hg2? (98%) presented also the highest percentage of CH3Hg? (0.7%). These are high values, showing that care should be taken to avoid the transport of this material to the hydrological system. Further studies on the transfer through the food chain would be very important

Avalia??o da exposi??o da popula??o de Passagem de Mariana (MG) aos elementos-tra?o, com ?nfase ao ars?nio.

O distrito de Passagem de Mariana, localizado na por??o sudeste do Quadril?tero Ferr?fero, MG, constitui uma ?rea intensamente afetada pela explora??o aur?fera desde o s?culo XVIII. As minas de ouro antigas exp?em minerais sulfetados ? oxida??o, liberando lentamente elementos-tra?o, com destaque para o As, para ?guas subterr?neas e superficiais. O abastecimento em determinadas resid?ncias desse distrito ? feito atrav?s de capta??o de ?guas de minas abandonadas, isentas de tratamento e monitoramento de qualidade, sendo essas utilizadas para consumo dom?stico. Neste contexto, o objetivo desse estudo foi a caracteriza??o geoqu?mica das ?guas de consumo de reservat?rios da esta??o de tratamento de ?gua e de antigas minas de ouro abandonadas e avaliar a exposi??o da popula??o aos elementos-tra?o, com ?nfase ao ars?nio atrav?s das an?lises de urina e cabelo. Nas ?guas de minas e da esta??o de tratamento de ?gua (ETA) o ?nion principal foi o bicarbonato (HCO3?), e o c?tion predominante foi o c?lcio, sendo, portanto classificadas como bicarbonatadas-c?lcicas. Observou-se que todas as amostras apresentaram concentra??es de ars?nio acima do limite de quantifica??o (LQ), por?m quatro amostras ultrapassaram o valor m?ximo permitido estabelecido pela Portaria 518 do Minist?rio da Sa?de de 10 ?g.L-1. As concentra??es de ars?nio nas amostras de ?gua variaram de 0,07 a 44,0 ?g.L-1. As concentra??es de ferro e mangan?s de algumas amostras excederam o limite estabelecido pela portaria 518 do Minist?rio da Sa?de. No ribeir?o do Carmo as concentra??es de ars?nio em todas as amostragens, variaram de 13,7 a 22,9 ?g.L-1, excedendo o limite m?ximo permitido estabelecido pela COPAM de 10 ?g.L-1. O teor de Mn foi superior ? concentra??o de Fe e Al, variando de 454 a 924 ?g.L-1, ultrapassando o valor m?ximo permitido de 100 ?g.L-1. Com rela??o ?s an?lises de amostras de urina de 93 moradores de comunidade de Passagem de Mariana, foram detectadas concentra??es, acima do LQ, dos elementos As, Cd, Co, Cr, Ni, Mn e Fe. O ars?nio foi encontrado em 51,6% das amostras, com concentra??es variando de 8,20 a 211 ?g.L-1. Algumas amostras de urina do grupo controle, referente ?queles indiv?duos que n?o consomem ?gua contaminada por elementos-tra?o, apresentaram concentra??es elevadas de ars?nio, constatando que a ?gua n?o era o ?nico meio de exposi??o a esse elemento. Foram criados dois novos grupos: grupo controle efetivo e grupo exposto por fontes diversas, que apresentavam faixas de concentra??o de As de 8,20 a 12,5 ?g.L-1 e 9,80 a 211 ?g.L-1, respectivamente. Dentre as 93 amostras de urina avaliadas, 7 apresentaram concentra??es de As acima de 40 ?g.L-1, o que significa que estas concentra??es est?o muito elevadas e que podem causar riscos ? sa?de. Atrav?s da estat?stica verificou-se que 33% da popula??o do distrito de Passagem de Mariana apresentam concentra??o de ars?nio em amostras de urina na faixa de risco toxicol?gico, ou seja, acima de 15 ?g.L-1, sendo 11% (? 1,1) da popula??o com concentra??es de ars?nio superiores a 40 ?g.L-1. Nas amostras de cabelo dos residentes de Passagem de Mariana, foram encontradas concentra??es acima do LQ, dos elementos-tra?o As, Cd, Co, Cr, Cu, Fe, Mn, Ni e Zn. A concentra??o de As variou entre 0,048 a 0,925 ?g.g-1. Somente o Cu apresentou concentra??o mais elevada em rela??o aos dados encontrados na literatura, cuja concentra??o variou de 11,1 a 280 ?g.g-1 nas amostras de cabelo. Os demais elementos apresentaram concentra??es compat?veis com valores de refer?ncia obtidos em outros estudos. Verificou-se, portanto, que a popula??o de Passagem de Mariana est? sendo afetada pela contamina??o de alguns elementos-tra?o na ?gua e outras fontes, sendo poss?vel observar, a concentra??o de As urin?rio elevada, o que indica exposi??o recente a esse elemento. A avalia??o da concentra??o de As nas amostras de cabelo, aparentemente encontra-se regular, visto que os teores detectados est?o abaixo do valor de refer?ncia. Por?m n?o se pode desconsiderar a possibilidade de efeitos adversos ? sa?de causada por esse elemento-tra?o.The district of Passagem de Mariana, located in the Southeastern area of the Quadril?tero Ferr?fero, Minas Gerais State, is characterized by the occurrence of several old gold mines and comprises an area intensely affected by the gold exploitation since the 18th century. The old mines expose sulfide minerals to oxidation, releasing trace-elements slowly, especially arsenic (As) to underground and surface water. The water supply in certain houses of this district is carried out through collection of water in abandoned mines, having neither treatment nor monitoring of its quality. This water is used to household consumption. In this context, this study aimed the geochemical characterization of supply water from the reservoirs of the water treatment plant and from old abandoned gold mines and to evaluate the exposure of the population to the trace elements, specially arsenic, through analysis of urine and hair. In the waters from the mines and the treatment plant the main anion was the bicarbonate (HCO3?), and the predominant cation was calcium, therefore they were classified as calcic-bicarbonated. It was observed that all samples presented arsenic concentrations above the limit of quantification (LOQ), however four samples exceeded the maximum value allowed established by Act 518 of Health Ministry of 10 ?g.L-1. Arsenic concentrations in the water samples ranged from 0.07 to 44.0 ?g.L-1. Iron and manganese concentrations in some samples exceeded the limit established by Act 518 of Health Ministry. In Ribeir?o do Carmo the concentrations of arsenic in all samplings ranged between 13.7 and 22.9 ?g.L-1, exceeding the maximum limit allowed established by COPAM of 10 ?g.L-1. Manganese concentration was higher than iron and aluminum, ranging between 454 and 924 ?g.L-1, surpassing the maximum value allowed of 100 ?g.L-1. Regarding the analyses of urine samples from 93 residents in Passagem de Mariana, all the following elements were detected at concentrations higher than the quantification limit: As, Cd, Co, Cr, Ni, Mn and Fe. Arsenic was found in 51.6% of the samples, at concentrations ranging from 8.20 to 211 ?g.L-1. Some urine samples from the control group, composed by individuals who do not consume the water contaminated with trace-elements, presented high concentrations of arsenic, showing that the water was not the only way of exposure to this element. Two new groups were created: effective control group and several sources exposed group, which presented ranges of As concentration of 8.20 to 12.5 ?g.L-1 and 9.80 to 211 ?g.L-1, respectively. Among the 93 urine samples essayed, 7 presented As concentrations above 40 ?g.L-1, which means that these concentrations are very high and may be harmful to health. Through statistics, it was verified that 33% of the population in Passagem de Mariana district present arsenic concentration in urine samples within the range of toxicologic risk, that is, over 15 ?gL-1. Eleven percent of the population presented arsenic concentration higher than 40 ?gL-1. In the hair samples of the residents of Passagem de Mariana, concentrations above the quantification limit were found of the trace-elements: As, Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn. As concentration ranged between 0.048 and 0.925 ?g.g-1. Only Cu presented concentration higher than the data found in literature, whose concentration ranged from 11.1 to 280 ?g.g-1 in the hair samples. All other elements presented concentrations compatible with the reference values obtained in other studies. It was observed, therefore, that some individuals in Passagem de Mariana are being affected by contamination with some trace-elements such as Fe, Mn, Co, Ni, As, Cd, Cr, Cu and Zn through water and other sources, with noticeable high concentrations of these elements in the biological samples. The high concentration of arsenic in urine indicates recent exposure to this element and constitutes the highest environmental risk observed in this study. The evaluation of As concentration in the hair samples is apparently regular, since the values detected are below the reference value. However, the possibility of adverse effects to the health caused by this trace-element cannot be ignored

Quantificação de metilmercúrio em sedimento e organismos fitoplanctônicos : estudo do caso da área contaminada de Descoberto - Minas Gerais

Exportado OPUSMade available in DSpace on 2019-08-14T12:22:40Z (GMT). No. of bitstreams: 1 tese_doutorado_louise_mendes.pdf: 11191321 bytes, checksum: 25163343970ff741a5c12e97a2e399f2 (MD5) Previous issue date: 5Em 2002, Hg metálico foi encontrado enterrado em uma área rural da cidade de Descoberto, Brasil e embora vários estudos tenham sido conduzidos para avaliar a contaminação da área, nenhum deles investigou a presença de Hg metilado no sistema hídrico. Neste trabalho, o CH3Hg+ foi determinado utilizando cromatografia gasosa-pirólise-detecção de fluorescência atômica em material sedimentado pela chuva e sedimentos próximos à área contaminada. A quantificação da concentração de Hg total juntamente com a especiação química por termodessorção foram realizadas. A concentração de HgT encontrada no material coletado em uma das caixas de sedimentação foi muito alta, de até 41580 µg kg-1. As amostras do Córrego Rico e Ribeirão do Grama mostraram uma faixa de HgT de 5,8 a 266 µg kg-1. A análise de termodessorção mostrou predominância de Hg2+, com boa correlação positiva com matéria orgânica e enxofre total. A concentração de CH3Hg+ em amostras de sedimentos de rio variou de <0,07 a 1,87 µg kg-1 e nas amostras das caixas de sedimentação as concentrações na estação seca foram de 1,33 e 8,0 µg kg-1. Estes são valores elevados, mostrando que deve ser tomado cuidado para evitar o transporte deste material para o sistema hídrico. Os Capítulos 2 e 4 descrevem a validação de dois métodos para quantificação de CH3Hg+ por CG-pyro-AFS: amostras de sedimento e cianobactérias. O sedimento é um dos principais locais de produção de CH3Hg+ e as cianobactérias participam da biotransformação do mercúrio nessa espécie. Todo o procedimento de validação seguiu os protocolos do guia INMETRO - DOQ-CGCRE-008. Os resultados mostraram que os dois métodos não apresentam efeito de matriz; boa linearidade (0,994) na faixa de 0 a 400 pg de CH3Hg+; Repetibilidade de 3%; Precisão intermediária de 8%; Ensaios de recuperação em amostras enriquecidas na faixa de 93 a 129%; e limites de detecção de 0,04 µg kg-1 para sedimento e 1,3 µg kg-1 para cianobactérias. Os materiais de referência CRM580 e DORM-3 foram utilizados para avaliar a exatidão do método, resultando em recuperações de 95 e 89%, respectivamente. Os métodos foram, portanto, adequados para o objetivo proposto e podem ser usados como ferramentas importantes em análises de rotina e/ou estudos do ciclo biogeoquímico de Hg. O ensaio de metilação de Hg2+ mostrou que a microalga Stichococcus sp. coletada na área contaminada de Descoberto pode ser a responsável pela produção de CH3Hg+ .In 2002, metallic Hg was found buried in a rural area of Descoberto city, Brazil, and although a number of studies have been conducted in order to assess the contamination of the area, none of them investigated the presence of methylated Hg in the hydric system. In this work methylmercury (CH3Hg+) was determined using gaschromatography-pyrolysis-atomic fluorescence detection (CG-pyro-AFS) in material from rain sedimentation boxes and stream sediments near the contaminated area. Total Hg (HgT) concentration along with the chemical speciation by thermo-desorption were performed. The HgT concentration in material from the sedimentation boxes was foundto be very high, up to 41,580 g kg-1. The samples from the Grama and Rico streams show a range of HgT from 5.8 to 266 g kg-1. The thermo-desorption analysis showed predominance of Hg2+, with a good positive correlation with organic matter and total sulfur. The CH3Hg+ concentration in stream sediment samples ranged from <0.04 to1.87 g kg-1and in the samples of sedimentation boxes the concentrations were 1.33 and 8.0 g kg-1 during dry season. These are high values show that care should be taken to avoid the transport of this material to the hydrological system. Chapters 2 and 4 describe the validation of two methods for determination of CH3Hg+ by GC-pyro-AFS: sediment samples and cyanobacteria. Sediment is one of themajor sites of CH3Hg+ production and cyanobacteria are likely responsible for the biotransformation of mercury (Hg) into this species. The whole validation procedure followed the protocols of INMETRO guide DOQ-CGCRE-008. The results showed that the two methods do not present matrix effect; good linearity (0.994) in the range of 0 to 400 pg CH3Hg+; repeatability of 3%; intermediate precision of 8%. Spiked recovery assays of samples in the range of 93 to 129%; and detection limits of 0.04 g kg-1 of sediment and 1.3 g kg-1 of cyanobacteria. Reference materials CRM580 and DORM-3 were used to evaluate the accuracy of the method, resulting in 95 and 89% recoveries,respectively. The methods were, therefore, adequate for the proposed objective and can be used as important tools in routine analyzes and/or studies of the biogeochemical cycle of Hg. The methylation assay of Hg2+ showed that the microalgae Stichococcus sp. collected in the contaminated area of Descoberto may be responsible for theproduction of CH3Hg+

Stress and depression in teachers from a public education institution

Objetivos: Analizar la presencia de estrés y signos indicativos de depresión en docentes de una institución pública de enseñanza. Material y Métodos: Estudio analítico, realizado con 163 docentes de una institución pública de enseñanza. Se aplicó Escala de estrés percibido-EEP e inventario de depresión de Beck-IDB. Resultados: De los 163 participantes, 108 (66,3%) eran del género masculino, 64 (39,3%) con rango de edad de 30 a 39 años, 79 (48,5%) tenían una renta salarial de más de 15 salarios (en el caso de las mujeres). La mayoría presentó título de maestro, 84 (51,5%). Se identificaron niveles mínimos de estrés en hombres, 73 (67,0%) y 34 (63,0%) en mujeres. 87 (79,8%) mujeres y 35 (64,8%) hombres presentaron un nivel de depresión mínima. Hubo diferencias significativas en los escores de estrés y depresión entre los sexos. Se observó una correlación positiva moderada entre las escalas. Conclusión: Los docentes con niveles mínimo y leve están sujetos a presentar estrés y depresión, mereciendo atención por parte de las instituciones.RESUMO Objetivos: Analisar a presença de estresse e sinais indicativos de depressão em docentes de uma instituição pública de ensino. Material eMétodos: Estudo analítico, realizado com 163 docentes de uma instituição pública de ensino. Aplicou-se Escala de Estresse Percebido-EEP e Inventário de Depressão de Beck-IDB. Resultados: Dos 163 participantes, 108 (66,3%) eram do gênero masculino, 64 (39,3%) com faixa etária de 30 a 39 anos, 79 (48,5%) tinham uma renda salarial de mais de 15 salários mínimos, 80 (49,1%) referiram cor parda. A maioria apresentou título de mestre, 84 (51,5%). Identificaram-se níveis mínimos de estresse em homens, 73 (67,0%) e 34 (63,0%) em mulheres. 87 (79,8%) mulheres e 35 (64,8%) homens apresentaram nível de depressão mínima. Houve diferença significativa nos escores de estresse e depressão entre os sexos. Observou-se uma correlação positiva moderada entre as escalas. Conclusão: Os docentes com níveis mínimo e leve estão sujeitos a apresentarem estresse e depressão, merecendo atenção por parte das instituições.ABSTRACT Objectives: To analyze the presence of stress and signs indicative of depression in teachers of a public educational institution. Materials and Methods: An analytical study was conducted with 163 teachers from a public educational institution. The Perceived Stress Scale-EEP and Beck-IDB Depression Inventory were applied. Results: Of the 163 participants, 108 (66.3%) were males, 64 (39.3%) were between 30 and 39 years of age, 79 (48.5%) had a wage income of more than 15 wages minimum, 80 (49.1%) reported brown color. The majority had a master's degree, 84 (51.5%). Minimal levels of stress were identified in men, 73 (67.0%) and 34 (63.0%) in women. 87 (79.8%) women and 35 (64.8%) men had minimal depression. There was a significant difference in the stress and depression scores between the sexes. There was a moderate positive correlation between the scales. Conclusion: Teachers with minimal and light levels are subject to stress and depression, deserving attention from the institutions

Speciation and quantification of Hg in sediments contaminated by artisanal gold mining in the Gualaxo do Norte River, Minas Gerais, SE, Brazil.

The Iron Quadrangle in SE Brazil was, in the eighteenth century, one of the most important Au producing regions of Brazil. In this region, gold is produced, even today, by artisanal methods that use Hg to increase the extraction efficiency with no control of Hg release to water systems and the atmosphere. In this context, the Gualaxo do Norte River is of particularinterest; its springs are located in the Doce River basin, an important Brazilian basin that supplies water for 3.5 million people. The main goal of this work was to quantify and speciate the Hg in the sediments of the Gualaxo do Norte River using a direct mercury analyzer and gas chromatography-pyrolysis-atomic fluorescence detection system. Statistical analyses consisted of principal component analysis, aiming to assess interactions among elements and species and to group the variables in factors affecting the properties of sediment. The results show that total Hg (THg) and methylmercury (CH3Hg+) concentrations in samples ranged from 209 to 1207 ?g kg?1 and from 0.07 to 1.00 ?g kg?1, respectively (methylation percentages from 0.01 to 0.27%). Thermal desorption analysis showed that mercury is mainly present in the oxidized form, and correlation analyses pointed to a relationship between THg and MnO, indicating that manganese can oxidize and/or adsorb Hg. Together, MO and CH3Hg+ are important parameters in the third principal component, indicating the influence of OM on the methylation process. This first investigation on Hg methylation in this small-scale gold mining area points to the possibility of Hg bioaccumulation and to the need of better understanding the biogeochemical cycle of Hg in this area. Samples were collected in 2012, prior to the 2015 Fund?o Dam disaster. The results are also a record of the characteristics of the sediment prior to that event

Determination of methylmercury in sediment and cyanobacteria samples : method validation and application to methylation investigation.

The aim of this work was to validate two methods for methylmercury (CH3Hg+) determination in sediments and cyanobacteria and their application to the Hg methylation study of planktonic organisms in water from a contaminated site in Brazil. Analytical methods for the determination of CH3Hg+ include many steps, and the necessity of adaptation to different matrices is very common and not always easy. In addition, these adaptations require new optimization and validation, which are found in a few articles using the matrix sediments but in none with planktonic organisms. The methods presented here were based on the extraction of CH3Hg+ from these matrices, derivatization, trapping, thermal desorption, GC separation, pyrolysis and detection by AFS (GC-pyro-AFS). The results showed good linearity (0.994) in the range of 0 to 400 pg CH3Hg+ with a repeatability of 3%, an intermediate precision of 8%, a recovery in spiked sample tests in the range of 93 to 129%, and detection limits of 0.04 mg kg 1 for sediments and 1.3 mg kg 1 for cyanobacteria. Certified reference materials showed good recoveries. The method for the cyanobacteria matrix was used for the Hg2+ methylation assay with cultures of cyanobacteria and microalgae isolated from water samples collected in an ancient Hg-contaminated gold mining area in Brazil. The production of CH3Hg+ was detected only in the culture of the microalga Stichococcus species (0.23% of total Hg), indicating its participation in the biotransformation of Hg. The methods can be used as important tools in routine analysis and/or studies of the biogeochemical cycle of Hg

Speciation and quantification of Hg in sediments contaminated by artisanal gold mining in the Gualaxo do Norte River, Minas Gerais, SE, Brazil

The Iron Quadrangle in SE Brazil was, in the eighteenth century, one of the most important Au producing regions of Brazil. In this region, gold is produced, even today, by artisanal methods that use Hg to increase the extraction efficiency with no control of Hg release to water systems and the atmosphere. In this context, the Gualaxo do Norte River is of particularinterest; its springs are located in the Doce River basin, an important Brazilian basin that supplies water for 3.5 million people. The main goal of this work was to quantify and speciate the Hg in the sediments of the Gualaxo do Norte River using a direct mercury analyzer and gas chromatography-pyrolysis-atomic fluorescence detection system. Statistical analyses consisted of principal component analysis, aiming to assess interactions among elements and species and to group the variables in factors affecting the properties of sediment. The results show that total Hg (THg) and methylmercury (CH3Hg+) concentrations in samples ranged from 209 to 1207 ?g kg?1 and from 0.07 to 1.00 ?g kg?1, respectively (methylation percentages from 0.01 to 0.27%). Thermal desorption analysis showed that mercury is mainly present in the oxidized form, and correlation analyses pointed to a relationship between THg and MnO, indicating that manganese can oxidize and/or adsorb Hg. Together, MO and CH3Hg+ are important parameters in the third principal component, indicating the influence of OM on the methylation process. This first investigation on Hg methylation in this small-scale gold mining area points to the possibility of Hg bioaccumulation and to the need of better understanding the biogeochemical cycle of Hg in this area. Samples were collected in 2012, prior to the 2015 Fund?o Dam disaster. The results are also a record of the characteristics of the sediment prior to that event