Espécies de lagartos como bioindicadoras de qualidade ambiental

Abstract

At the global level, concern about the contamination of the environment is notable and growing, considering that with the most polluting technological advances, nature is launched, like pesticides and electronic waste. In addition, human activities can enhance natural polluters, such as natural radiation and heavy metals removed from mining companies. Based on these facts, biomonitoring has been a very useful tool for the evaluation of toxic agents in the environment. Through environmental monitoring, especially using bioindicator organisms, it is possible to identify priority areas that are more contaminated or that present worrying natural factors such as the case of natural radiation, and thus direct efforts and studies to recover areas and mitigate impacts on the ecosystem. . In this perspective, this study aimed to review the world literature on the use of lizard species as model organisms to evaluate environmental contamination, and to test a species of endemic and saxicolous lizard in the Caatinga area of northeastern Brazil as a biomonitor of resulting genotoxic effects contamination by radioisotopes and other natural pollutants. Field work was carried out to collect specimens of the lizard Phyllopezus periosus, from December 2018 to July 2019, in three areas with different levels of natural radiation, namely a protected natural area - ESEC Seridó, an area with mining activity - the Brejuí Mine, and the area of the municipality of Lajes Pintadas, with a high incidence of radiation. In all lizard specimens found, after anesthesia under refrigeration, blood samples were collected and micronucleus tests were performed; environmental data were also collected, such as outcrop water samples and gamma radiation present in the air. During the review work, studies were found with ten families of lizards, using organic and inorganic contaminants, and it was found that most of the contaminants tested are toxic to animals, causing histopathological effects, oxidative stress and DNA damage. Our field study found a statistically significant difference for both micronuclei and nuclear alterations, including a wide variety of nuclear abnormalities, hitherto not previously identified. When nuclear changes were compared between locations, the most significant areas were Mina Brejuí and Lajes Pintadas. It was found, therefore, that lizards respond well to environmental changes, a fact that highlights them as relevant biomonitor organisms, as they are sensitive to several types of environmental contaminants including natural radiation.