Biomonitoramento da qualidade do ar da cidade de Uberlândia por meio de ensaios citogenéticos com Tradescantia

Abstract

CHAPTER II: The aim of this study was to address the lack of information concerning the air quality in the city of Uberlândia, Minas Gerais, Brazil. In this study, we conducted an unprecedented experiment involving the in situ biomonitoring of air genotoxicity in the city center during and after a public transportation strike using the Tradescantia micronucleus test. The frequency of micronuclei was significantly higher in the city center compared with the reference site (Mann-Whitney test, p<0.05), with the highest MN levels being observed during public transport stoppage (Kruskal-Wallis, Dunn p<0.01). In addition, the multiple linear regression analyses revealed that the low circulation of buses during public transport stoppage and the increase in the concentration of particulate matter from the increased flow of vehicles in the city center during the strike positively influenced the MN frequency. CHAPTER III: The growing number of cars in large cities is directly linked to changes in the chemical composition of urban air, which increasingly has high concentrations of potentially genotoxic chemicals. Therefore, discovering and monitoring the risks associated with exposure to atmospheric pollutants is indispensible for preventing environmental and health problems. Because of the lack of reliable data regarding the air quality in the city of Uberlândia, the present study sought to test whether the genotoxic risks in areas with different levels of vehicular traffic can be measured using the Tradescantia micronucleus assay (Trad-MN). Therefore, more than 20 inflorescences were exposed to locations with different amounts of vehicular traffic twice per year from the winter of 2006 to the summer of 2011. The inflorescences were then analysed to determine the micronucleus (MN) frequency. In addition, we sought to determine the influence of factors linked to city climate on the MN frequencies obtained at each monitored location. Our results show that, although low relative humidity positively influenced MN formation in T. pallida tetrads, the major determining factor for genotoxic events was the level of vehicular traffic at the locations monitored over the five-year study.