Chemical composition of aerosol particles from direct emissions of vegetation fires in the Amazon Basin: water-soluble species and trace elements

Biomass burning is an important global source of aerosol particles to the atmosphere. Aerosol particles were collected in plumes of tropical forest and cerrado biomass burning fires in the Amazon Basin during August-September, 1992. Fine (d(p) <2 mu m, where d(p) is the aerodynamic diameter of the particle) and coarse (2 mu m < d(p) <10 mu m) aerosol particles were collected using stacked filter units. Up to 19 trace elements were determined using particle-induced X-ray emission analysis. Ion chromatography was used to determine up to 11 water-soluble ion components. The dominant species were black carbon, K+, Cl-, and SO42-. Organic matter represents in average 70-92% of the fine mode particle mass. The composition of the emitted particles in cerrado fires presents a well-defined pattern related to both the combustion phase and cerrado categories, which is not observed in the case of forest fires. Higher concentrations relative to the fine particulate mass were observed during the flaming emissions compared to the smoldering ones, for almost all experiments. Global emission flux estimates showed that biomass burning could be an important source of heavy metals and black carbon to the atmosphere. Estimates showed that savanna and tropical forest biomass burning could be responsible for the emission of about 1 Gg yr(-1) of copper, 3 Gg yr(-1) of zinc and 2.2 Tg yr(-1) of black carbon to the atmosphere. In average, these values correspond to 2, 3 and 12%, respectively, of the global budget of these species. (C) 2000 Elsevier Science Ltd. All rights reserved.