Epiphytic lichens on air biomonitoring in Belo Horizonte City, Brazil: a preliminary assessment

摘要

Belo Horizonte is the fifth most populous city in Brazil and there is no data on the level of its atmospheric pollution concerning chemical elements. This study was conducted as a preliminary survey using lichens as biomonitors collected from two parks: Municipal Americo Rene Giannetti, downtown, and Mangabeiras, far from the city centre, a place regarded as not polluted. Epiphytic lichens were collected and their elemental compositions were determined by neutron activation technique, ko-method. In this assessment, the local atmospheric condition could be assessed pointing out the presence of typical tracers of vehicular emissions, mainly in Municipal park. On the other hand, soil elements seem to be expressive in the air composition, mainly in Mangabeiras area. Being a perceptive differential, the high concentration of soil elements found in the Mangabeiras park samples seems to come from the surrounding mining areas. The mining dust may have been the source of these elements.