Elemental composition of PM10 and PM2.5 for a savanna (Cerrado) region of southern Amazonia

摘要

Brazil plays an important role with regard to the emission of aerosols into the atmosphere. Ecosystems such as the Amazonian tropical forest and Brazilian Cerrado are undergoing sweeping changes. These human activities promote an increase in the levels of gases and particles emitted into the atmosphere. To determine how these activities have affected the emission of coarse and fine particulate matter (PM10 and PM2.5), atmospheric aerosol samples were collected continuously from June 2004 to April 2005 in the Cuiaba Basin of south-central Mato Grosso, Brazil. Aerosols were sampled using stacked filter units. Filters were analysed for particulate mass, black carbon and for concentrations of seventeen elements by Particle Induced X-Ray Emission. The results revealed that Mg, Al, Si, S, K, Ca, Ti and Fe were the major components detected in PM2.5 and PM10. The high enrichment factors observed in PM2.5 and PM10 suggest that anthropogenic activities were the predominant source for elements such as Cu, Zn and Pb. These data indicate that most of the aerosols measured in the Cuiaba Basin originate from land conversion and biomass burning. These patterns are similar to those observed in other Cerrado and Amazonian forest areas that are undergoing rapid and spatially extensive land-cover change.