Aerosol Source Apportionment study in São Paulo city

Author(s)

Andrea Dardes de Almeida Castanho

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 1999-09-01

Examining board members

Paulo Eduardo Artaxo Netto; Artemio Plana Fattori; Vito Roberto Vanin

• Advisor: Paulo Eduardo Artaxo Netto

Abstract

The urban air pollution issue is a concern in the entire world mostly because of its hazardous effect to human health. São Paulo metropolitan area is a very industrialized region with an intense traffic of vehicles. Its geographical and meteorological conditions are unfavorable to pollution dispersion, especially in the winter season. In order to achieve a better understanding of the air pollution sources and the importance of vehicle emissions, two sampling campaigns were carried out. Inhalable particulate matter was sampled using Stacked Filter Units separated in fine and coarse particulate modes, providing mass concentration and elemental composition by Particle Induce X-ray Emission (PIXE). Real time aerosol monitors provided PM10 aerosol concentration (TEOM), organic and elemental carbon concentration (Carbon Monitor 5400R&P) and black carbon concentration (Aethalometer). Measurements of gas concentrations were performed by Differential Optical Absorption Spectroscopy (DOAS). High levels of pollutant concentrations were measured during the winter season. For several times the concentrations exceeded the national quality standard limit, reinforcing the importance of a better understanding of this process. A complex system of sources and meteorological conditions modulates the air pollution of the urban area of São Paulo. The boundary layer and the direct emissions modulate the diurnal cycle obtained for PM10, black carbon, CO, NOx, SO2. Absolute Principal Components Analyses results showed a very good agreement in the identification of the sources for the winter and summer field campaigns, pointing that there is no significant change in the sources. Traffic Source represented 28% and 24% of the fine aerosol for winter and summer respectively. Resuspended soil dust accounted for 25% and 30%. Oil combustion source represented 18% and 21%. Sulfates explained 23% and 17% and finally industrial contributed with 5% and 6% of fine particulate matter, for winter and summer respectively. These five sources account for the fine mode particulate source apportionment. The resuspended soil dust accounted for (75-78%) of the coarse aerosol fraction. All analysis identified the responsability of the traffic of vehicles for the direct emission of several gases and particulate pollutants and for the resuspended soil dust. The sampling and analytical procedures showed that it is possible to perform a quantitative aerosol source apportionment in a complex urban area such as São Paulo. (AU)

• FAPESP's process: 97/00844-0 - The quantitative determination of sources of particulate material in the atmosphere in the city of São Paulo
• Grantee: Andréa Dardes de Almeida Castanho
• Support Opportunities: Scholarships in Brazil - Master