Avaliação de contaminação por mercúrio em Descoberto - MG

• Autor(a) principal: Tinôco, Ana Amélia Paulino
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3698
• topic: Contaminação; Mercúrio; Água; Solo; Sedimentos; Contamination; Mercury; Water; Soil; Sediments; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::GEOTECNICA

Aspects related to mercury contamination have attracted the scientific community's attention because of its high potential toxicity and the importance of its biogeochemical cycle. Mercury is a chemical element considered unessential to any metabolic process, however, it is easily accumulated in most organisms. It is found naturally in both organic and inorganic forms in solid, liquid and gaseous states. Consequently, its biochemical cycle involves processes that occuring in soil, water and the atmosphere. The main concern in Brazil is environmental contamination by mercury in gold mining areas, which represents one of the most considerable sources of anthropogenic mercury. In 2002 elementary mercury was found in the city of Descoberto, located in the Zona da Mata of Minas Gerais State, situated 370 Km of Belo Horizonte whose origin may be related to the gold mining in this region in the nineteenth century. Residents of the rural area noticed the presence of this element when a slope was cut to open an access road to a private property after a long rain period that provoked the emergence of liquid mercury. Based on previous studies, the aims of this work were to i) analyze the concentration of mercury in samples of water, particulate material, soil, sediment and fishes in new, potentially contaminated areas of the Bacia do Ribeirão do Grama; ii) establish local reference (background) values in samples of soil and sediments; and iii) establish counterevidence of the data previously obtained in this region using a more sensitive detection method for mercury in water. Two study areas and one area to establish local reference values were defined; however, significant mercury concentrations were found in soil and sediment sample, in the reference area, which may difficult the identification of sources of pollution at the site. These data were therefore included in the study areas. Based on our data, it was possible to verify the existence of pollution by mercury in soil, sediments and water in the study region that may be associated to past gold mining activities.