Subject(s)
Betacoronavirus , Coronavirus Infections , Pandemics , Pneumonia, Viral , COVID-19 , Humans , SARS-CoV-2 , South AmericaSubject(s)
Humans , Pneumonia, Viral , Coronavirus Infections , Pandemics , Betacoronavirus , South AmericaABSTRACT
INTRODUCTION: In some Amazonian river basins, hair mercury concentration is above the recommended levels. We evaluated the influence of birth geographical location in the hair mercury level of Amazonian riverine children. MATERIALS AND METHODS: Hair mercury concentration was measured in 219 children living in four Amazonian riverine communities: Tapajós River (São Luiz do Tapajós and Barreiras villages, n = 110), Tocantins River (Limoeiro do Ajurú village, n = 61), and Caeté River (Caratateua village, n = 48). We used Poisson regression analysis to evaluate the association between native and non-native children from each village and its hair mercury concentration. RESULTS: Higher mercury exposure was found in native children from São Luiz do Tapajós (range = 0.81-22.38 µg/g) followed by native children from Barreiras (range = 0.48-13.46 µg/g), non-native children from São Luiz do Tapajós (range = 0.26-22.18 µg/g), non-native children from Barreiras (range = 0.43-20.76 µg/g), followed by the children from Caeté and Tocantins river basins. We observed that Tapajós villages' native children had higher prevalence of mercury exposure children than other children (p < 0.05). CONCLUSIONS: Birth geographical location has association to mercury levels in the hair of children who lived in a same community with history of mercury exposure.
Subject(s)
Child Development , Environmental Exposure/analysis , Geography, Medical , Mercury/analysis , Adolescent , Adult , Brazil , Child , Female , Hair/chemistry , Humans , Male , Pregnancy , Prenatal Exposure Delayed Effects/diagnosis , Prenatal Exposure Delayed Effects/etiology , Rivers , Water Pollutants, Chemical/adverse effectsABSTRACT
Mercury is an important source of environmental contamination affecting human beings throughout the world and especially in the Amazon. Riverside populations have been chronically exposed to relatively high levels of methylmercury for many years. Long-term effects of mercury exposure are not well known, but human genotoxicity was already showed in both in vitro and epidemiological studies. However, to date, only two studies were carried out in Amazonian populations with conflicting results and without comparing to a non-exposed population. Aiming to highlight this question and avoid interference factors, this work analyzed in vitro genotoxicity of mercury in blood lymphocytes of Amazonian individuals by two methods (micronucleus and chromosomal aberrations). Deleterious effects of low levels (1-500 µg/l or 0,004-2 µM) of methylmercury were only detected with the method to detect chromosomal aberrations. Mitotic index (proportion of cells in metaphase) was the parameter most sensible. Thus, this technique was applied for the analysis of an Amazonian non-exposed population (Panacauera) with similar social-economical characteristics of the exposed populations studied elsewhere. The mean of the mitotic index for Panacauera population was 0.0814 ± 0.0097. Inter-individual variability of this index had no relation with sex or age. This value was above those registered for some groups of exposed populations. This fact points to mercury as the main responsible for inhibiting the cell cycle and/or the loss of proliferative capacity of the cells. These results already support mitotic index as an essential parameter for the early diagnose of mercury genotoxicity in humans, and especially in Amazonian populations.
Subject(s)
Mercury/toxicity , Mutagens/toxicity , Water Pollutants, Chemical/toxicity , Adolescent , Adult , Brazil , Chromosome Aberrations/chemically induced , Environmental Exposure/analysis , Humans , Lymphocytes/drug effects , Male , Mercury/blood , Methylmercury Compounds/blood , Methylmercury Compounds/toxicity , Micronucleus Tests , Mining , Mutagens/metabolism , Water Pollutants, Chemical/blood , Young AdultABSTRACT
Neurotoxicity induced by methylmercury (MeHg) increases the formation of reactive radicals and accelerates free radical reactions. This review summarizes recent findings in the MeHg-induced formation of free radicals and the role of oxidative stress in its neurotoxicity. Oxidative stress on CNS can produce damage by several interacting mechanisms, including mitochondrial damage with increase in intracellular free Ca(2+), activation and inhibition of enzymes, release of excitatory amino acids, metallothioneins expression, and microtubule disassembly. The nature of antioxidants is discussed and it is suggested that antioxidant enzymes and others antioxidants molecules may protect the central nervous system against neurotoxicity caused by MeHg.
Subject(s)
Antioxidants/metabolism , Methylmercury Compounds/toxicity , Nervous System/drug effects , Animals , Humans , Nervous System/metabolism , Oxidative StressABSTRACT
Amazonian gold mining activity results in human exposure to mercury vapor. We evaluated the visual system of two Amazonian gold miners (29 and 37 years old) by recording the transient pattern electroretinogram (tPERG) and transient pattern visual evoked potential (tPVEP). We compared these results with those obtained from a regional group of control subjects. For both tPERG and tPVEP, checkerboards with 0.5 or 2 cycles per degree (cpd) of spatial frequency were presented in a 16 degrees squared area, 100% Michelson contrast, 50cd/m2 mean luminance, and 1 Hz square-wave pattern-reversal presentation. Two averaged waveforms (n=240 sweeps, 1s each) were monocularly obtained for each subject in each condition. Both eyes were monocularly tested only in gold miners. Normative data were calculated using a final pooled waveform with 480 sweeps. The first gold miner, LCS, had normal tPERG responses. The second one, RNP, showed low tPERG (P50 component) amplitudes at 0.5 cpd for both eyes, outside the normative data, and absence of response at 2 cpd for his right eye. Delayed tPVEP responses (P100 component) were found at 2 cpd for LCS but the implicit times were inside the normative data. Subject RNP also showed delayed tPVEP responses (all components), but only the implicit time obtained with his right eye was outside the normative data at 2 cpd. We conclude that mercury exposure levels found in the Amazon gold miners is high enough to damage the visual system and can be assessed by non-invasive electrophysiological techniques.
Subject(s)
Electroretinography , Evoked Potentials, Visual/physiology , Mercury Poisoning/diagnosis , Vision Disorders/diagnosis , Adolescent , Adult , Brazil , Electrophysiology , Female , Gold , Humans , Male , Mercury Poisoning/complications , Mercury Poisoning/physiopathology , Middle Aged , Mining , Reference Values , Vision Disorders/etiology , Vision Disorders/physiopathologyABSTRACT
Introdução: Em áreas endêmicas, a malária representa um grande fator de risco para o baixo peso ao nascer, aumentando os índices de morbi-mortalidade infantil. Objetivo: Avaliar as consequências da malária sobre o peso de recém-nascidos, os autores avaliaram a freqüência do baixo peso entre recém-nascidos de 23 mulheres procedentes de áreas endêmicas da Amazônia que desenvolveram malária durante a gravidez. Método: O estudo foi conduzido no Núcleo de Medicina Tropical/UFPA, com a colaboração do Instituto Evandro Chagas, onde as pacientes tiveram a confirmação diagnóstica e, da Clínica Roumiê e Hospital Fundação Santa Casa de Misericórdia do Pará nos quais foram obtidos dados sobre as condições do parto e dos recém-nascidos. Resultados: O baixo peso ao nascer menor que 2.500g associou-se a malária em 13,4 por cento e, em 8,6 por cento no grupo controle não havendo diferença significativa entre as médias dos 2 grupos. Não houve diferença também, entre as médias de peso de RN, ao considerar os grupos infectados por P. vivax (3.100 ñ 594,3 g) e P. falciparum (2.780 ñ 682,2 g) P>0,05. Considerando-se a idade gestacional em que ocorreu a infecção e o estado semi imune das gestantes, não se observou baixo peso aonascer. Conclusões: A freqüência de baixo peso ao nascer é relativamente baixa em áreas endêmicas da Amazônia e este fato está associado a quimioprofilaxia administrada durante a gravidez, corroborando diversos estudos realizados em outras áreas endêmicas do mundo
Subject(s)
Humans , Infant, Newborn , Pregnancy , Malaria , Infant, Low Birth Weight , Plasmodium falciparum , Plasmodium vivaxABSTRACT
A região amazônica é responsável pela maioria dos casos de malária registrados no Brasil. Nessa região, pouco tem sido estudado sobre efeitos da doença durante a gestação. Visando contribuir para o conhecimento da malária em área endêmica da Amazônia, os autores propõem descrever as conseqüências da malária falciparum em multípara semi-imune, procedente da reserva indígena localizada na divisa Pará - Maranhão. Os dados epidemiológicos, parasitológicos, laboratoriais e clínicos - evolutivos foram obtidos, parcialmente, da paciente hospitalizada no Hospital Universitário João de Barros barreto (HUJBB) e complementados com as informações do agente da FUNAI, acompanhante. Foram observadas as seguintes alterações: - no organismo materno: anemia, alterações neurológicas (forma cerebral da malária) e a interrupção da gravidez; na placenta lesões vasculares e pigmento malárico no espaço interviloso; sobre o concepto: morte intra útero e expulsão (aborto no 1§ trimestre). conclui-se que em área endêmica de malária na Amazônia Oriental, as gestantes, ainda que semi-imunes, podem desenvolver formas graves da doença com sérios danos para o concepto
