Aplicação do mapeamento geoquímico para a avaliação de contaminações ambientais no Quadrilátero Ferrífero - MG

Abstract

The natural processes and human activities are continuously changing the chemical composition of our environment, therefore it is important to determine the current concentration and spatial distribution of the chemical elements on the surface. The following work deals with the geochemical mapping of the leaves Belo Horizonte, Ouro Preto and Igarapé, scale 1: 100,000, located in the Quadrilátero Ferrífero region that was chosen for this research, due to its geological-mineral, agricultural, biological, water and social potential. The objective of this work was to determine the regional background of some elements of environmental importance that were selected and mapping points with anomalous concentrations for them in the region. A total of 731 active current sediment samples collected during the project "Geochemistry of the Quadrilátero Ferrífero and its surroundings" was carried out by CPRM - Geological Survey of Brazil. The uni-bi and multivariate statistical treatments of the data were performed and 6 factorial maps with regional geochemical signatures and 7 unielemental ones were produced for the selected elements characterizing their distributions, backgrounds and points with anomalous values that were compared to international quality standards for sediment. It is concluded that for the studied region that the main source of enrichment is geogenic having naturally high backgrounds for the analyzed elements, when compared to the global averages, therefore special attention and care is necessary when defining contaminations in the area, considering that values and regional base standards are different. It was possible to infer from this mapping that the existence of anthropogenic activities, in a timely manner, may actually be corroborating for the geochemical anomalies obtained, but more in-depth research is necessary for these hypotheses to be proven.