Mi comunidad se cuida del mercurio: Bolivia

El mercurio es un elemento químico metálico que está presente de forma natural en el aire, el agua y los suelos. Asimismo, se utiliza en la minería de oro artesanal y en pequeña escala (MAPE). El problema es que la exposición al mercurio y sus compuestos (incluso a pequeñas cantidades) puede causar graves problemas de salud; puede ser tóxico para los sistemas nervioso e inmunitario, el aparato digestivo, la piel y los pulmones, así como los riñones y la vista. La principal vía de exposición humana al metilmercurio es el consumo de pescado y mariscos contaminados. Este material en forma de rotafolio ha sido elaborado por la Organización Panamericana de la Salud (OPS), inicialmente con el Ministerio de Salud de Perú, y en esta segunda versión, modificada para el contexto de Bolivia, con la colaboración del Ministerio de Salud y Deportes de este último país y profesionales que han contribuido con datos nacionales para tratar el tema. El rotafolio servirá como apoyo en las sesiones de orientación dirigidas a los hombres y mujeres responsables de la salud de los menores, así como del bienestar integral de quienes acuden a los establecimientos de salud, o en las sesiones educativas que se realicen en las comunidades afectadas por la MAPE. Se espera que el material sirva de apoyo para las acciones de prevención a la exposición por mercurio y para el cuidado de la salud en Bolivia, especialmente para las poblaciones en condiciones de vulnerabilidad, como poblaciones indígenas, mujeres, niños y niñas.

Mercury in muscle and liver of Plagioscion squamosissimus (Acanthuriformes: Sciaenidae) from the Machado River, Brazilian Amazon / Mercúrio no músculo e fígado de Plagioscion squamosissimus (Acanthuriformes: Sciaenidae) do Rio Machado, Amazônia brasileira

The Machado River is the main tributary of the Madeira River in the state of Rondônia, a region that has been impacted by deforestation, livestock, urban development, alluvial gold mining and urban and industrial effluents that likely contribute to the introduction of mercury (Hg) in the aquatic system. We aimed to determine the concentrations of total Hg (THg) in muscle and liver of Plagioscion squamosissimus, a main fishing resource in the region. Fish were sampled for two years at five sites, along a 90-km stretch of the middle Machado River. THg concentrations were analyzed in 64 muscle and 54 liver samples by cold vapor atomic absorption spectrophotometry (FIMS-400). THg levels were related with fish size and sex and with periods of the hydrological cycle. THg concentrations in both organs were positively and significantly related with fish body size. There was no significant variation in THg among periods of the hydrological cycle. Mean THg concentrations in muscle (1.09 ± 0.72 mg kg-1) and liver (1.28 ± 1.23 mg kg-1) were higher than the limit established by the WHO. Our results suggest that residual mercury from former alluvial gold extraction and lixiviation of mercury naturally occurring in the soil due to large-scale deforestaion is accumulating in the aquatic food chain in the Machado River. We conclude that it is necessary to monitor the levels of mercury in commercially important fish species in the region.(AU)

O Rio Machado é o principal afluente do Rio Madeira no estado de Rondônia, uma região impactada por desmatamento, pecuária, desenvolvimento urbano, mineração de ouro e efluentes urbanos e industriais, que provavelmente contribuem para a introdução de mercúrio (Hg) no sistema aquático. Nosso objetivo foi determinar as concentrações de Hg total (THg) em músculo e fígado de Plagioscion squamosissimus, um importante recurso pesqueiro na região. Os peixes foram amostrados durante dois anos em cinco locais ao longo de 90 km no médio Rio Machado. As concentrações de THg foram analisadas em 64 amostras de músculos e 54 de fígado por espectrofotometria de absorção atômica com vapor frio (FIMS-400). As concentrações de mercúrio foram relacionadas ao tamanho e sexo dos peixes, e com períodos do ciclo hidrológico. As concentrações de THg em ambos os órgãos foram relacionadas positiva e significativamente com o tamanho corporal dos peixes. Não houve variação significativa do THg entre os períodos do ciclo hidrológico. As concentrações médias de THg no músculo (1,09 ± 0,72 mg kg-1) e no fígado (1,28 ± 1,23 mg kg-1) foram superiores ao limite estabelecido pela OMS. Os resultados sugerem que o mercúrio residual da extração de ouro e lixiviação de mercúrio que ocorre naturalmente no solo desmatado está se acumulando na cadeia alimentar aquática do Rio Machado. Concluímos que é necessário monitorar os níveis de mercúrio em espécies de peixes comerciais na região.(AU)

Vitamin-mineral supplements do not guarantee the minimum recommendations and may imply risks of mercury poisoning in dogs and cats.

Given the importance of using the vitamin-mineral supplements to guarantee the minimum nutritional recommendations for pets in homemade foods, and hypothesizing that these products may contribute to toxic metals contamination, the present study aimed to determine the concentrations of essential minerals and toxic metals in vitamin-mineral supplements available in the Brazilian market and calculate if the amount recommended by the manufacturer guarantees the minimum recommendations of NRC (2006) and FEDIAF (2020), as well as calculating the amount of toxic metals that animals would consume, according to the amounts recommended by the manufacturer. Seven vitamin-mineral supplements were analyzed. The determination of essential minerals and toxic metals was performed using ICP-OES. Comparisons were made with the minimum recommendations for essential minerals, and with the maximum tolerated levels of toxic metals established by the FDA (2011), descriptively. Most of the vitamin-mineral supplements, in the quantities recommended by the manufacturers, do not guarantee the minimum recommendations of NCR (2006) and FEDIAF (2020) for the following elements: calcium, potassium, magnesium, sodium, phosphorus, selenium, and zinc. Only one supplement had detectable selenium concentrations. Three supplements provided more than 0.02mg of mercury/kg of body weight, the safe upper limit used to establish the maximum tolerated level of this element. It is concluded that most vitamin-mineral supplements do not meet the minimum recommendations for most essential minerals and, if formulated by untrained professionals, even with supplementation, homemade foods may still be nutritionally deficient. Furthermore, some vitamin-mineral supplements analyzed may imply risks of mercury poisoning in pets.

Trimetazidine Protects from Mercury-Induced Kidney Injury.

INTRODUCTION: The presence of mercury in the environment is a worldwide concern. Inorganic mercury is present in industrial materials, is employed in medical devices, is widely used in batteries, is a component of fluorescent light bulbs, and it has been associated with human poisoning in gold mining areas. The nephrotoxicity induced by inorganic mercury is a relevant health problem mainly in developing countries. The primary mechanism of mercury toxicity is oxidative stress. Trimetazidine (TMZ) is an anti-ischemic drug, which inhibits cellular oxidative stress, eliminates oxygen-free radicals, and improves lipid metabolism. The aim of this study was to evaluate whether the administration of TMZ protects against mercuric chloride (HgCl2) kidney damage. METHODS: Adult male Wistar rats received only HgCl2 (4 mg/kg bw, sc) (Hg group, n = 5) or TMZ (3 mg/kg bw, ip) 30 min before HgCl2 administration (4 mg/kg bw, sc) (TMZHg group, n = 7). Simultaneously, a control group of rats (n = 4) was studied. After 4 days of HgCl2 injection, urinary flow, urea and creatinine (Cr) plasma levels, Cr clearance, urinary glucose, and sodium-dicarboxylate cotransporter 1 (NaDC1) in urine were determined. Lipid peroxidation (MDA) and glutathione (GSH) levels were measured in kidney homogenates. RESULTS: Rats only treated with HgCl2 showed an increase in urea and Cr plasma levels, urinary flow, fractional excretion of water, glucosuria, and NaDC1 urinary excretion as compared with the control group and a decrease in Cr clearance. TMZHg group showed a decrease in urea and Cr plasma levels, urinary flow, fractional excretion of water, glucosuria, NaDC1 urinary excretion, and an increase in Cr clearance when compared to the Hg group. Moreover, MDA and GSH levels observed in Hg groups were decreased and increased, respectively, by TMZ pretreatment. CONCLUSION: TMZ exerted a renoprotective action against HgCl2-induced renal injury, which might be mediated by the reduction of oxidative stress. Considering the absence of toxicity of TMZ, its clinical application against oxidative damage due to HgCl2-induced renal injury should be considered. The fact that TMZ is commercially available should simplify and accelerate the translation of the present data "from bench to bedside." In this context, TMZ become an interesting new example of drug repurposing.

Evaluation of cytoprotective effects of compounds isolated from Copaifera langsdorffii Desf. against induced cytotoxicity by exposure to methylmercury and lead.

Copaifera langsdorffii L. is one of the most known medicinal species in Brazil. Its leaves are rich in phenolic compounds with potential biological activities as an antioxidant and chelating agent. This paper reports the isolation of four compounds from the hydroalcoholic extract of the leaves of C. langsdorffii and the investigation of their possible cytoprotective effects against heavy metal poisoning. Quercitrin (1), afzelin (2), 3,5-di-O-(3-O-methyl galloyl) quinic acid (3) and 4,5-di-O-(3-O-methyl galloyl) quinic acid (4), were associated with toxic doses of methylmercury and lead and evaluated by Alamar blue cell viability assays in HepG2 and PC12. The compounds displayed significant cytoprotective effect for the HepG2 cell line against both metals. Compounds 1-4 did not protect PC12 cells against methylmercury induced-cytotoxicity, but at lower concentrations, they protected against lead induced-cytotoxicity. The evaluated compounds showed a promising cytoprotection effect against exposure to heavy metals and should be further investigated as protective agents.

Total mercury in wild felids occurring in protected areas in the central Brazilian Amazon / Mercúrio total em felinos selvagens em áreas protegidas na Amazônia central brasileira

This is the first study to investigate mercury (Hg) contamination in felid species in the Brazilian Amazon. We collected 26 fur samples from wild felids of four species (Puma concolor, Panthera onca, Leopardus pardalis and Leopardus wiedii) occurring in the Mamirauá and Amanã sustainable development reserves, in the state of Amazonas. Samples were from museum specimens, except for five P. onca samples collected from free-living individuals. Total Hg concentrations ranged from 0.12 to 48.1 µg g-1. Concentrations of Hg did not differ significantly between museum specimens and live individuals of P. onca, but varied significantly among species, with significantly higher concentrations for P. onca and L. pardalis, which could be related to factors such as diet and habitat.(AU)

Este é o primeiro estudo a investigar a contaminação por mercúrio (Hg) em espécies de felinos na Amazônia brasileira. Foram coletadas 26 amostras de pelo de felinos selvagens de quatro espécies (Puma concolor, Panthera onca, Leopardus pardalis e Leopardus wiedii) ocorrendo nas reservas de desenvolvimento sustentável Mamirauá e Amanã, no estado do Amazonas. As amostras foram coletadas de espécimes de museu, exceto cinco amostras de P. onca obtidas de indivíduos capturados em vida livre. As concentrações de Hg variaram de 0,12 a 48,1 µg g-1. Não houve diferença significativa entre a concentração de Hg no pelo de espécimes de museu e de indivíduos vivos de P. onca. Houve variação significativa entre espécies, sendo que P. onca e L. pardalis tiveram concentrações significativamente mais altas, o que pode estar relacionado a fatores como dieta e hábitat.(AU)

Exposición a mercurio de las personas que trabajan en la minería artesanal de oro, Costa Rica, 2015-2016 / Exposure to mercury from people working in artisanal mining of gold, Costa Rica, 2015-2016

Resumen Introducción: la minería artesanal de oro es una actividad económica que se realiza principalmente en países de bajos ingresos. Durante esta actividad se utiliza el mercurio para la recuperación de oro, el cual tiene diversas formas de afectación a la salud humana, especialmente por la inhalación del vapor de mercurio. Objetivo: describir los mecanismos de exposición al mercurio de las personas que trabajan en la minería artesanal de oro, en las Juntas de Abangares, Costa Rica, 2015-2016. Materiales y métodos: se aplicó un cuestionario para conocer factores de riesgo. Además, se utilizó una lista de chequeo para observar el proceso de minería artesanal de oro. Finalmente, se realizó la medición de concentraciones de mercurio atmosférico en los lugares de trabajo para conocer los límites de mercurio al que se encontraban expuestas las personas. Resultados: durante el proceso de quemado se libera vapor de mercurio, además, existen factores de riesgo que incrementan el riesgo de intoxicación al mercurio al no utilizar el equipo de protección personal adecuado durante la realización de la actividad minera. Conclusiones: las personas participantes que trabajan en minería artesanal de oro utilizan tecnología que no cuenta con los requisitos necesarios para minimizar sus riesgos, especialmente la retorta y su función de evitar el escape de mercurio.

Abstract Introduction: Artisanal gold mining is an economic activity that is done primarily in low-income countries. During this activity, mercury is used for the recovery of gold, which has various ways of affecting human health, especially by inhalation of mercury vapor. Aim: describe the mechanisms of exposure to mercury from people working in artisanal mining of gold, on the boards of Abangares, Costa Rica, 2015-2016. Materials and methods: A questionnaire was applied to learn about risk factors. In addition, a checklist was used to observe the process of artisanal gold mining. Finally, it was made the measurement of atmospheric mercury concentrations in the workplace to learn the limits of mercury to which people were exposed. Results: The measurements indicated that release of mercury vapor is generated during the burning process, and the personal protective equipment was not suitable during the conduct of mining activity. There are risk factors that increase the risk of mercury poisoning. Conclusions: the participants who work in artisanal gold mining use technology that does not have the necessary requirements to minimize their risks, especially the retort and its function to prevent the escape of mercury.

Amalgama y mercurio. Visión y evolución en la odontología restauradora actual / Amalgam and mercury. Vision and evolution in current restorative dentistry

La amalgama dental ha sido un material restaurador muy confiable, de gran utilidad en la odontología y que, aún con su gran aceptación y amplio uso en la profesión dental, ha presentado siempre muy limitado reconocimiento profesional, por su poca o nula capacidad estética o de color de diente y por las «guerras¼ que ha tenido que librar a través de sus muchos años de vida. El mercurio es un componente importante en la mezcla de la amalgama dental, y su presencia ha sido uno de los factores preponderantes que han causado el detrimento injusto del uso de este material restaurador, que ha demostrado un comportamiento clínico excelente en sus casi 200 años de vida (AU)

Dental amalgam has been a very trustable restorative material, highly utilized in dentistry and although with high acceptance and ample use in the dental profession, it has always had to deal with limited professional acknowledgement due to little or poor esthetic and lack of tooth color and because of the many «wars¼ it has to fight in the many years of life. Mercury is a very important component of the mix in the dental amalgam and its presence has been one of the key factors that has caused the unjustified detriment of the use of this restorative material that has shown an excellent clinical behavior in the almost 200 years of life (AU)

Avaliação da concentração de mercúrio em rações caninas comercializadas em Niterói, Rio de Janeiro / Evaluation of the mercury concentration in canine feeds sold in Niterói, Rio de Janeiro

Dentre os metais pesados de maior preocupação para saúde humana e animal, tem-se o mercúrio, cuja forma orgânica é a mais agressiva aos sistemas. A fonte mais comum de adquirir tal metal é através do consumo de pescado e seus derivados, sendo que para os pets (animais de companhia) a ingestão é via rações formuladas com tal matriz alimentar. Logo, foram feitas análises através do DMA 80 de tal elemento em distintas rações comerciais no município de Niterói para avaliar a qualidade do produto ofertado. Os resultados para as rações úmidas de peixe apresentaram 80% em desacordo com a legislação vigente para alimentos humanos, sendo necessário mais estudos e uma legislação específica para mercúrio para alimentação animal.(AU)

Avaliação da concentração de mercúrio em rações caninas comercializadas em Niterói, Rio de Janeiro / Evaluation of the mercury concentration in canine feeds sold in Niterói, Rio de Janeiro

Dentre os metais pesados de maior preocupação para saúde humana e animal, tem-se o mercúrio, cuja forma orgânica é a mais agressiva aos sistemas. A fonte mais comum de adquirir tal metal é através do consumo de pescado e seus derivados, sendo que para os pets (animais de companhia) a ingestão é via rações formuladas com tal matriz alimentar. Logo, foram feitas análises através do DMA 80 de tal elemento em distintas rações comerciais no município de Niterói para avaliar a qualidade do produto ofertado. Os resultados para as rações úmidas de peixe apresentaram 80% em desacordo com a legislação vigente para alimentos humanos, sendo necessário mais estudos e uma legislação específica para mercúrio para alimentação animal.

Contaminação mercurial em tucunaré (Cichla spp. ) de uma comunidade do Amazonas / Mercurial contamination in tucunaré (Cichla spp. ) from an Amazonas state community, Brazil

O mercúrio é um dos principais contaminantes ambientais, sendo a ação antrópica, tanto industrial quanto de garimpo de ouro no Norte do país, responsável por uma parcela expressiva desta contaminação. Extremamente tóxico, o mercúrio pode acometer o sistema nervoso central e levar a óbito. O consumo de peixes contaminados é umas das principais fontes de exposição humana. Foram analisadas 15 amostras de tecido muscular de tucunarés, capturados no reservatório de Balbina (Presidente Figueiredo), no analisador direto de mercúrio (DMA - 80®). Todas apresentaram contaminação mercurial acima do permitido pela legislação (1mg/Kg de mercúrio total). Os valores mínimo e máximo encontrados foram, respectivamente, 1,08mg/Kg e 6,79mg/Kg. Não foi constatada correlação entre peso e comprimento dos peixes com a concentração de mercúrio total dos mesmos.

Contaminação mercurial em tucunaré (Cichla spp. ) de uma comunidade do Amazonas / Mercurial contamination in tucunaré (Cichla spp. ) from an Amazonas state community, Brazil

O mercúrio é um dos principais contaminantes ambientais, sendo a ação antrópica, tanto industrial quanto de garimpo de ouro no Norte do país, responsável por uma parcela expressiva desta contaminação. Extremamente tóxico, o mercúrio pode acometer o sistema nervoso central e levar a óbito. O consumo de peixes contaminados é umas das principais fontes de exposição humana. Foram analisadas 15 amostras de tecido muscular de tucunarés, capturados no reservatório de Balbina (Presidente Figueiredo), no analisador direto de mercúrio (DMA - 80®). Todas apresentaram contaminação mercurial acima do permitido pela legislação (1mg/Kg de mercúrio total). Os valores mínimo e máximo encontrados foram, respectivamente, 1,08mg/Kg e 6,79mg/Kg. Não foi constatada correlação entre peso e comprimento dos peixes com a concentração de mercúrio total dos mesmos.(AU)

Effects of Chronic Exposure to Mercury on Angiotensin-Converting Enzyme Activity and Oxidative Stress in Normotensive and Hypertensive Rats / Efeitos da Exposição Crônica ao Mercúrio sobre a Atividade da Enzima Conversora de Angiotensina e Estresse Oxidativo em Ratos Normotensos e Hipertensos

Abstract Background: Mercury's deleterious effects are associated with increased cardiovascular risk. Objective: To determine whether chronic exposure to inorganic mercury increases the activity of angiotensin-converting enzyme and its relationship with oxidative stress in several organs and tissues. Methods: We studied male Wistar and spontaneously hypertensive rats (SHR) (3-month-old) exposed or not to HgCl2 for 30 days. At the end of treatment, we investigated the following: changes in body weight, hemodynamic parameters, angiotensin-converting enzyme (ACE) activity and oxidative stress in the heart, aorta, lung, brain and kidney in hypertensive compared to normotensive animals. A value of p < 0.05 was considered significant. Results: Chronic exposure to HgCl2 did not affect weight gain in either group. Systolic blood pressure, measured weekly, did not increase in Wistar rats but showed a small increase in SHR rats. We also observed increases in left ventricular end-diastolic pressure and ACE activity in the plasma and hearts of normotensive rats. In the SHR+Hg group, ACE activity increased in plasma but decreased in kidney, lung, heart, brain and aorta. Oxidative stress was assessed indirectly by malondialdehyde (MDA) production, which increased in Hg-treated rats in both plasma and heart. In the SHR+Hg group, MDA increased in heart and aorta and decreased in lungs and brain. Conclusion: These results suggest that chronic exposure to inorganic mercury aggravates hypertension and produces more expressive changes in ACE activity and oxidative stress in SHRs. Such exposure affects the cardiovascular system, representing a risk factor for the development of cardiovascular disorders in normotensive rats and worsening of pre-existing risks for hypertension.

Resumo Fundamento: Os efeitos deletérios do mercúrio estão associados ao risco cardiovascular aumentado. Objetivo: Determinar se a exposição crônica ao mercúrio inorgânico aumenta a atividade da enzima conversora de angiotensina e sua relação com o estresse oxidativo em vários órgãos e tecidos. Métodos: Estudamos ratos Wistar e ratos espontaneamente hipertensos (SHR) (3 meses de idade) expostos ou não a HgCl2 por 30 dias. Ao final do tratamento, investigamos: alterações de peso, parâmetros hemodinâmicos, atividade da enzima conversora de angiotensina (ECA) e estresse oxidativo no coração, aorta, pulmão, cérebro e rim de animais hipertensos comparados a animais normotensos. Um valor de p < 0,05 foi considerado significativo. Resultados: A exposição crônica ao HgCl2 não afetou o ganho de peso em nenhum dos grupos. A pressão arterial sistólica, medida semanalmente, não aumentou em ratos Wistar, mas mostrou um pequeno aumento nos ratos SHR. Também observamos aumentos na pressão diastólica final do ventrículo esquerdo e na atividade da ECA no plasma e no coração de ratos normotensos. No grupo SHR + Hg, a atividade da ECA aumentou no plasma, mas diminuiu no rim, pulmão, coração, cérebro e aorta. O estresse oxidativo foi avaliado indiretamente pela produção de MDA, que aumentou nos ratos tratados com Hg tanto no plasma quanto no coração. No grupo SHR + Hg, o MDA aumentou no coração e na aorta e diminuiu nos pulmões e no cérebro. Conclusão: Estes resultados sugerem que a exposição crônica ao mercúrio inorgânico agrava a hipertensão e produz mudanças mais expressivas na atividade da ECA e no estresse oxidativo em SHRs. Essa exposição afeta o sistema cardiovascular, representando um fator de risco para o desenvolvimento de distúrbios cardiovasculares em ratos normotensos e para piorar riscos pré-existentes para hipertensão.

Human exposure to mercury and its hematological effects: a systematic review.

Mercury is a metal found in the environment from natural and anthropogenic sources. It is highly toxic to ecosystems and living beings. Most human exposures come from ingestion of contaminated seafood, outgassing from dental amalgam or occupational exposure (e.g. gold mining), among other cases. Large populations are exposed to mercury, making it a very important issue from the public health perspective. Adverse health effects are commonly seen in the nervous system, but every organ is a potential target, such as the bone marrow. The main goal of this study was to assess the available evidence on human exposure to mercury and its hematological effects. A search strategy was constructed, including key terms (MeSH, text word and equivalents) for querying 2 repositories of master dissertation and PhD thesis (Fiocruz/ARCA and University of São Paulo) and 4 different electronic databases: BVS/LILACS, MEDLINE/PubMed, Scopus and TOXLINE/NIH, for articles published from 1950 to February 2018. There was no language restriction and a tool (EPHPP) was used to assess the quality of included studies. According to pre-established criteria, 80 studies were retrieved, all of them observational (48 case reports, 24 cross-sectional, 6 case series and 2 cohorts), comprising 9,284 people. Despite the fact that most exposed ones (6,012) had normal blood cell count and mercury hematological effects did not seem very usual (1,914 cases: 14 severe and 29 deaths), three studies reported association (ß) for anemia, lymphopenia, neutrophilia and basophilia. We concluded that the gathered information pointed to mercury hematotoxic effects, some of them may be serious and even fatal.

Effects of Chronic Exposure to Mercury on Angiotensin-Converting Enzyme Activity and Oxidative Stress in Normotensive and Hypertensive Rats.

BACKGROUND: Mercury's deleterious effects are associated with increased cardiovascular risk. OBJECTIVE: To determine whether chronic exposure to inorganic mercury increases the activity of angiotensin-converting enzyme and its relationship with oxidative stress in several organs and tissues. METHODS: We studied male Wistar and spontaneously hypertensive rats (SHR) (3-month-old) exposed or not to HgCl2 for 30 days. At the end of treatment, we investigated the following: changes in body weight, hemodynamic parameters, angiotensin-converting enzyme (ACE) activity and oxidative stress in the heart, aorta, lung, brain and kidney in hypertensive compared to normotensive animals. A value of p < 0.05 was considered significant. RESULTS: Chronic exposure to HgCl2 did not affect weight gain in either group. Systolic blood pressure, measured weekly, did not increase in Wistar rats but showed a small increase in SHR rats. We also observed increases in left ventricular end-diastolic pressure and ACE activity in the plasma and hearts of normotensive rats. In the SHR+Hg group, ACE activity increased in plasma but decreased in kidney, lung, heart, brain and aorta. Oxidative stress was assessed indirectly by malondialdehyde (MDA) production, which increased in Hg-treated rats in both plasma and heart. In the SHR+Hg group, MDA increased in heart and aorta and decreased in lungs and brain. CONCLUSION: These results suggest that chronic exposure to inorganic mercury aggravates hypertension and produces more expressive changes in ACE activity and oxidative stress in SHRs. Such exposure affects the cardiovascular system, representing a risk factor for the development of cardiovascular disorders in normotensive rats and worsening of pre-existing risks for hypertension.

Human exposure to mercury and its hematological effects: a systematic review / Exposição humana ao mercúrio e seus efeitos hematológicos: uma revisão sistemática / Exposición humana al mercurio y sus efectos hematológicos: una revisión sistemática

Mercury is a metal found in the environment from natural and anthropogenic sources. It is highly toxic to ecosystems and living beings. Most human exposures come from ingestion of contaminated seafood, outgassing from dental amalgam or occupational exposure (e.g. gold mining), among other cases. Large populations are exposed to mercury, making it a very important issue from the public health perspective. Adverse health effects are commonly seen in the nervous system, but every organ is a potential target, such as the bone marrow. The main goal of this study was to assess the available evidence on human exposure to mercury and its hematological effects. A search strategy was constructed, including key terms (MeSH, text word and equivalents) for querying 2 repositories of master dissertation and PhD thesis (Fiocruz/ARCA and University of São Paulo) and 4 different electronic databases: BVS/LILACS, MEDLINE/PubMed, Scopus and TOXLINE/NIH, for articles published from 1950 to February 2018. There was no language restriction and a tool (EPHPP) was used to assess the quality of included studies. According to pre-established criteria, 80 studies were retrieved, all of them observational (48 case reports, 24 cross-sectional, 6 case series and 2 cohorts), comprising 9,284 people. Despite the fact that most exposed ones (6,012) had normal blood cell count and mercury hematological effects did not seem very usual (1,914 cases: 14 severe and 29 deaths), three studies reported association (β) for anemia, lymphopenia, neutrophilia and basophilia. We concluded that the gathered information pointed to mercury hematotoxic effects, some of them may be serious and even fatal.

O mercúrio é um metal que pode ser encontrado naturalmente no meio ambiente e através de fontes antropogênicas. É altamente tóxico para ecossistemas e seres vivos. A maior parte da exposição humana provém da ingestão de pescados contaminados, da liberação de gases da amálgama dentária ou da exposição ocupacional (p.ex.: extração de ouro). Vastas populações são expostas ao mercúrio, tornando-se uma questão de saúde pública muito importante. Efeitos adversos à saúde são comumente observados no sistema nervoso, mas todos os órgãos são alvos em potencial, como a medula óssea. O principal objetivo do estudo foi avaliar as evidências disponíveis sobre a exposição humana ao mercúrio e seus efeitos hematológicos. Uma estratégia de busca foi realizada, incluindo termos chave (palavras-chave, palavras do texto e equivalentes), para pesquisar dois repositórios de dissertações de mestrado e teses de doutorado (Fiocruz/ARCA e Universidade de São Paulo) e quatro bases de dados eletrônicas: BVS/LILACS, MEDLINE/PubMed, Scopus e TOXLINE/NIH (artigos publicados de 1950 até fevereiro de 2018). Não houve restrições de linguagem e uma ferramenta (EPHPP) foi utilizada para avaliar a qualidade dos estudos incluídos. De acordo com os critérios pré-estabelecidos, foram encontrados 80 estudos, todos observacionais (48 relatos de caso, 24 estudos transversais, 6 séries de casos e 2 coortes), que compreendiam 9.284 pessoas. Apesar do fato de que as pessoas mais expostas (6.012) tinham contagens de células sanguíneas normais, e os efeitos hematológicos do mercúrio não pareciam muito comuns (1.914 casos, 14 graves e 29 mortes), três estudos relataram a associação de (β) anemia, linfopenia, neutrofilia e basofilia. Concluímos que as informações coletadas indicam efeitos hematotóxicos do mercúrio, alguns dos quais podem ser muito graves e até fatais.

El mercurio es un metal que se puede encontrar de forma natural en el ambiente y mediante fuentes antropogénicas. Es altamente tóxico para los ecosistemas y seres vivos. Entre otras, la mayor parte de la exposición humana, proviene de la ingestión de pescado contaminado, liberación de gases de amalgamas dentales o exposición ocupacional (p.ej. extracción de oro). Vastas poblaciones están expuestas al mercurio, convirtiéndolo en un asunto muy importante desde la perspectiva de la salud pública. Los efectos adversos para la salud se observan comúnmente en el sistema nervioso, pero cada órgano es un objetivo potencial, como la médula ósea. El objetivo principal del estudio fue evaluar las evidencias disponibles sobre la exposición humana al mercurio y sus efectos hematológicos. Se realizó una estrategia de búsqueda, incluyendo términos clave (palabras-clave, palabras del texto y equivalentes), se consultaron 2 registros de trabajos finales de máster y tesis de doctorado (Fiocruz/ARCA y Universidad de São Paulo) y 4 bases de datos electrónicas diferentes: BVS/LILACS, MEDLINE/PubMed, Scopus y TOXLINE/NIH, para artículos publicados desde el año 1950, hasta febrero de 2018. No hubo restricciones de lengua y se usó la herramienta (EPHPP) para evaluar la calidad de los estudios incluidos. De acuerdo con los criterios preestablecidos, se recopilaron 80 estudios, todos observacionales (48 informes de casos, 24 estudios transversales, 6 series de casos, y 2 cohortes), que comprendieron a 9.284 personas. A pesar de que la mayoría de los expuestos (6.012) tenían un recuento normal de células sanguíneas y los efectos hematológicos del mercurio no parecían muy comunes (1.914 casos: 14 severos y 29 muertes), tres estudios informaron de la asociación (β) para anemia, linfopenia, neutrofilia y basofilia. Concluimos que la información recabada indicaba los efectos hematotóxicos del mercurio, algunos de los cuales pueden ser muy serios e incluso fatales.

Effects of diphenyl diselenide diet on a model of mercury poisoning.

This work investigated the preventive effect of diphenyl diselenide [(PhSe)2] against the toxic effects of mercury in silver catfish (Rhamdia quelen). The animals were treated during 30 consecutive days with a (PhSe)2 supplemented feed (3.0 mg kg-1) or commercial feed. During the last 5 days the animals received a daily intraperitoneal dose of HgCl2 (1.7 mg kg-1) or Saline (0.9%). Twenty-four hours after the last HgCl2 injection, the animals were euthanized by spinal cord section to biological material obtainment. Hepatic (AST and ALT) and renal (ammonia and creatinine) toxicity biomarkers, δ-ALA-D activity, TBARS, total and non-protein thiols levels and hepatic, renal and blood mercury (Hg) and zinc (Zn) content were evaluated. Considering renal parameters, HgCl2 exposition increased serum creatinine levels and decreased δ-ALA-D activity, total and non-protein thiols and TBARS levels. HgCl2 exposure also decreased blood δ-ALA-D activity. With exception of blood δ-ALA-D activity and total thiols levels, (PhSe)2 supplementation partially prevented mercury induced alterations. Animals exposed to HgCl2 presented an increase in liver and kidney Hg content and a decrease in liver and blood Zn content. The alteration in blood Zn content was partially prevented with (PhSe)2 supplementation. With the exception of mercury and zinc content, no effects of HgCl2 exposure on hepatic tissue were observed. These results show that (PhSe)2 supplementation can represent a promising alternative to prevent the toxic effects presented by Hg exposure.

Assessing mercury intoxication in isolated/remote populations: Increased S100B mRNA in blood in exposed riverine inhabitants of the Amazon.

Mercury is a heavy metal responsible for human intoxication worldwide and especially in the Amazon, where both natural and anthropogenic sources are responsible for exposure in riverine populations. Methylmercury is the most toxic specie of mercury with recognized neurotoxicity due to its affinity for the central nervous system. S100B protein is a well-established biomarker of brain damage and it was recently associated with mercury-related neurotoxicity. Accurate measurement is especially challenging in isolated/remote populations due to the difficulty of adequate sample conservation, therefore here we use S100B mRNA levels in blood as a way to assay mercury neurotoxicity. We hypothesized that individuals from chronically exposed populations showing mercury levels above the limit of 10 µg/g in hair would present increased levels of S100B mRNA, likely due to early brain damage. A total of 224 riverine individuals were evaluated for anthropometric data (age, body mass index), self-reported symptoms of mercury intoxication, c-reactive protein in blood, and mercury speciation in hair. Approximately 20% of participants showed mercury levels above the limit, and prevalence for most symptoms was not different between individuals exposed to high or low mercury levels. Rigorous exclusion criteria were applied to avoid confounding factors and S100B mRNA in blood was tested by RT-qPCR. Participants with ≥10 µg/g of mercury had S100B mRNA levels over two times higher than that of individuals with lower exposure. A significant correlation was also detected between mercury content in hair and S100B mRNA levels in blood, supporting the use of the latter as a possible candidate to predict mercury-induced neurotoxicity. This is the first report of an association between S100B mRNA and mercury exposure in humans. The combination of both exposure and intoxication biomarkers could provide additional support for the screening and early identification of high-risk individuals in isolated populations and subsequent referral to specialized centers.

[Subcutaneous injection of metallic mercury. The importance of early removal]. / Inyección subcutánea de mercurio elemental. Importancia de la remoción precoz.

Accidental or intentional subcutaneous or intramuscular injection of metallic mercury is an uncommon form of intoxication. We present the case of a 22 year-old man, who had psychotic disorders and autoaggressive behavior, with a preceding history of self-injection of mercury into the soft tissues of the neck, thorax and abdomen. Clinical examination, radiographs, and computed tomography showed the affected area. Mercury was measured in blood and urine. The mercury was surgically resected from the affected areas. Early detection and removal of mercury from the body by physical removal or chelation is required to prevent short- and long-term toxicity.