Utilização de liquens no monitoramento ativo e passivo da poluição atmosférica

Abstract

Air pollution has been widely studied because of its high potential to cause harm to human health as well as to the environment. Lichens have been used to monitor this type of pollution due to their high sensitivity to atmospheric pollutants and also due to their wide distribution in all environments. The present study aimed to perform active and passive biomonitoring with lichens in different points of Uberaba-MG. For this purpose the lichen species were surveyed in four points (urban and industrial regions) as passive biomonitoring. Lichen tides of the species Parmotrema tinctorum were transplanted from a preserved area for the study points as active biomonitoring, remaining exposed for 30 consecutive days in the rainy season and 30 days in the dry period. Afterwards the concentrations of the elements N, Fe, S, Cu and Zn in the llichen tides were measured and in the chlorosis area were analyzed. The diversity of lichens was influenced by air pollution in Uberaba, allowing the identification of areas with greater environmental disturbance, such as the Industrial District III, and less impacted as in point A, a residential neighborhood. In relation to the study of the elements absorbed by thallus of the P. tinctorum lichen was found to be effective as a bioaccumulator of S, Fe and Cu, because a significant difference was observed between the periods (dry and rainy) and between the study points, for S. However, for the other elements (N and Zn), this species of lichen showed no significant difference after the exposure period adopted. The study of the chlorosis areas in the thalus of P. tinctorum allowed us to conclude that this species was efficient for the active monitoring of air pollution, presenting a positive correlation with the concentration of N, S, Fe and Zn, and negative correlation with diversity lichen.