Determination of the organic composition of the São Paulo fine particles

Abstract

The research project for the period of visit of Dr. Pierre Herck is linked to the project Narrowing UNCERTAINTIES ON THE AEROSOL AND CLIMATE CHANGES IN SAO PAULO STATE - NUANCE-SPS (Process 08/58104-8). This thematic project aims to study the role of aerosols emitted by urban areas. For the Metropolitan Region of São Paulo is known that the main source of fine particles (those with the <2.5 micron) is the emission of light and heavy vehicles. Studies already published show that diesel vehicles could account for up to 50% of the concentration of fine particulates in Brazilian capitals (Andrade et al., 2011). These aerosols have very significant impact in terms of radiation and precipitation formation. The particles are composed mainly of carbonaceous material and secondary organic aerosols. There are many studies on the inorganic composition of aerosols, soluble ionic compounds and mass participation of Black Carbon, but there is still much uncertainty in the share of the organic fraction in atmospheric aerosol. In different studies with respect to the mass balance of atmospheric aerosol in Sao Paulo, it was observed that the organic fraction can reach 50% by weight of fine particulate. This result is very relevant to the description of the physical and chemical process. (AU)