Atmospheric particulate matter samples (PM2.5 and PM10) were collected at urban sites (São Paulo, SPA; Piracicaba, PRB) in São Paulo State, Brazil. In order to characterize the chemical composition of particulate matter, several chemical components were analyzed from the samples, and among these were inorganic and organic anions, monosaccharide anhydrides, and organic and elemental carbon. Long-range transport of the particulate matter while sugar cane was being burned contributed to an increase in PM2.5 and PM10 concentrations at the SPA site. Sulphate, nitrate, ammonium, elemental carbon and particulate organic material (POM) were major components of the total PM2.5 and PM2.5–10. The contribution of POM to PM2.5 at PRB was 29%, similar to the results found for the winter season at the SPA site.
The Cl–/Na+ ratio at the SPA site for PM2.5 was different from that at the other site, with chloride depletion indicating several sources beyond sea salt. The occurrence of levoglucosan and its correlations with potassium confirm the contribution of local biomass burning (at PRB) and long-range transported particles at SPA. OC/EC ratios and the correlation coefficients indicated secondary formation of OC at both sites.