Radionuclides incorporated by inhabitants of surrounding Brazilian uranium mines

Full text: Brazil has the 6th largest global geological reserve of uranium, with the main reserve in Santa Quiteria - CE still not under exploration. Currently, uranium mining and processing in Brazil only occur near to the city of Caetite - BA. Several Non-Governmental Organizations claim that uranium mining in this region is polluting and may jeopardize the human health and safety and the environment. However, those in charge of the complex extraction and production of 'yellow cake' for generating fuel to the nuclear power plants reject these allegations. U-238 may be deposited in the skeleton by replacing the calcium, thus it is possible to estimate its incorporation by determining its concentration in the teeth. This study aimed to identify potential problems caused by mining to the population of Caetite, analyzing U-238 contained in samples of teeth extracted for orthodontic reasons from Caetite residents. The concentration of thorium and potassium incorporated were also determined by ICP-MS, as well the cumulative dose of radiation received by this population was estimated. For comparison sake, the same analysis was performed in samples from Santa Quiteria and Aracaju - SE (used as a control area). The doses estimated were compared to doses obtained with EPR spectra of the same samples. The accumulated amount of radioisotopes in the teeth of the population of Caetite is probably due to natural origin, thus it is not possible to state that the mining process in Caetite increases pollution or radiation exposure in a meaningful way. (author)