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 a tmosphere. Aerosol particles were collected in plumes of tropical forest an d 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 p article) and coarse (2 mu m < d(p) <10 mu m) aerosol particles were collect ed using stacked filter units. Up to 19 trace elements were determined usin g 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 70-9 2% of the fine mode particle mass. The composition of the emitted particles in cerrado fires presents a well-defined pattern related to both the combu stion phase and cerrado categories, which is not observed in the case of fo rest fires. Higher concentrations relative to the fine particulate mass wer e observed during the flaming emissions compared to the smoldering ones, fo r almost all experiments. Global emission flux estimates showed that biomas s burning could be an important source of heavy metals and black carbon to the atmosphere. Estimates showed that savanna and tropical forest biomass b urning 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 g lobal budget of these species. (C) 2000 Elsevier Science Ltd. All rights re served.