Chemical speciation of atmospheric aerosol from the Amazon, the Atlantic Rainforest, and an agro-industrial region of São Paulo State: environmental and health aspects

Abstract

This project proposes to conduct a detailed study of the chemical speciation of atmospheric aerossols from three different Brazilian ecosystems: the Amazon rainforest, the Atlantic rainforest, and a region in the State of São Paulo where sugar cane plantation and processing is dominant. Our intention is to complement symbiotically three other projects that are underway in these regions. We intend to conduct an unparalleled investigation, quantifying 172 organic compounds in the atmospheric aerosol (using GC-MS), divided into 5 fractions, going from non-polar (n-alcanes) compounds to the most polar ones (sugars and acids). Our goal is to use the knowledge of the aerosol chemical composition, its temporal and spatial variations, to better understand the different chemical processes that form and transform these particles. Moreover, besides gaining a better knowledge about the processes that regulate the concentrations of a great diversity of chemicals in the troposphere, we will also be able to rigorously evaluate the hygroscopicity of the aerosol. This will give support to an improved knowledge about particle aging and the formation of cloud condensation nuclei. In addition to the environmental approach, this study will quantify polycyclic aromatic hydrocarbons that have known mutagenic and carcinogenic properties, and can therefore have consequences on human health. Sampling in the Amazon was established based on the Brazilian component of the 'GO-Amazon Project' that aims to evaluate the influence of the Manaus pollution plume in the rain pattern of the Amazon. In the Atlantic rainforest, samples will be taken in the city of Caraguatatuba (CNPq financed Project) located in a region that is undergoing major changes due to increasing industrialization. In the sugar cane cultivation areas, the atmospheric emissions are also going through great changes due to increasing mechanization of the harvest process. Our research group has conducted a preliminary study of organic chemical speciation of total particulate matter in this region (FAPESP - Climate Change Project), and now proposes to conduct this study separating the fine and coarse fractions to better understand the role of each of the fractions on the hydrophilic property of the low regional troposphere. At all three sites the organic markers will serve as a basis to better understand chemical and physical processes that occur in the present, and will also serve as a chemical record to be able to assess future changes. The exchange of informations between the different multidisciplinary groups involved in this research should be very enriching, leading to results of great impact. (AU)