Background radioativo do Granito Madeira, norte do Amazonas

Abstract

Determining the radioactive background (BG) of a mining region with the possibility of naturally occurring radioactive material is extremely important as it provides data for estimating human exposure to ionizing radiation, for the decommissioning of these facilities and for quantifying the human contribution to changing the environment. Naturally occurring radionuclides, such as those from the uranium and thorium decay chains, are present in rocks, soils, water, etc. But its distribution is not homogeneous: there are places like Granito Madeira, in Presidente Figueiredo, Amazonas, where its concentration is higher. Thus, in these places, dose rates due to gamma radiation emitted by natural isotopes show values ​​above the world average. The Madeira Granite is a unique case, as it is located within the Amazon Forest, 350km north of Manaus, and is under mining concession from a tin mining company. Thus, this work aims to present the monitoring of the BG relative to the gamma radiation of an unexplored part of the Granite Madeira. For this purpose, a NaI(Tl) scintillator was used to monitor the dose rates. These data were geoprocessed for spatial distribution and isodose curves.