Análise da exposição humana à radiação natural no munícipio de Lajes Pintadas, Rio Grande do Norte, semiárido brasileiro

Abstract

Brazil has one of the largest uranium reserves in the world. In the Brazilian Semiarid region, specifically in the municipality of Lajes Pintadas / RN, there are rocky outcrops with the presence of natural ionizers that release radon gas and, consequently, lead to the environment. This thesis aimed to investigate the presence of natural contaminants in the municipality of Lajes Pintadas / RN / Brazil and their responses to assess their harmful effects through biological tests. From 163 individuals, analyzes were performed on cells of the oral mucosa, using the micronucleus test with cytoma approach (BMCyt) to visualize and compare possible changes caused by exposure to lead and radon. In the homes chosen for the study, the passive emanometry method was used to quantify radon present in the air, which reached levels 30 times higher than those considered permissible by the World Health Organization, but one of the by-products, lead, was within the national quality recommendations. Effective exposure levels were detected covering the blood lead category from undetectable to 12 μg/dL. Regarding dangerous changes, the mean frequency of toxic shoots was 0.023±0.302, showing an increase when the mean control frequency was - 0.024±0.262; Regarding the binucleated cells, it was observed (4.13±5.79) twice that observed in the control region (0.234±4.29), the parameters may indicate the occurrence of gene amplification, as well as suggest alterations during the cytokine process during cell division. However, a significant response was not established regarding the data on the frequency of micronuclei of the exposed (0.200±0.671) compared to the group (0.00870±0.191). Thus, the level of exposure of lead to the population disclosed is not transmitted in their health status, a fact that needs to be furthered in research, both to ascertain the geogenic origin of lead, as well as the exposure of uranium by-products to the population.