The lizard Phyllopezus pollicaris (Spix, 1825) as a bioindicator of exposure to natural background radiation in a semi-arid region of Brazil.

This study investigated the potential of the lizard Phyllopezus pollicaris as a bioindicator of genotoxic damage caused by exposure to ionizing radiation in uranium-rich areas of Rio Grande do Norte State, Brazil. The hypothesis tested was that P. pollicaris is sensitive to ionizing radiation due to its wide distribution and generalist ecological behavior and may exhibit cytogenetic effects in areas with high natural background radiation. Blood samples were collected from specimens in three localities with medium to high natural background radiation levels in the Seridó Caatinga and were compared with samples from a low-radiation area, the Mata Estrela Reserve in the Atlantic Forest. Cytogenetic analyses were conducted by assessing the frequency of micronuclei and other nuclear abnormalities in erythrocytes using the micronucleus test. The results indicated a significant increase in the frequency of micronuclei and other nuclear abnormalities in specimens from areas with high natural background radiation compared to the absence of micronuclei (MN) in individuals from the Mata Estrela reference (non-exposed) area. Thus, this study suggests a link between ionizing radiation and genotoxic damage, highlighting the potential of P. pollicaris as a bioindicator of environmental quality in areas with high natural background radiation, such as the Seridó region of Rio Grande do Norte, Brazil.