No abstract

Atmospheric particulate matter samples (PM 2.5 and PM 10 ) 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 PM 2.5 and PM 10 concentrations at the SPA site. Sulphate, nitrate, ammonium, elemental carbon and particulate organic material (POM) were major components of the total PM 2.5 and PM 2.5-10 . The contribution of POM to PM 2.5 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 PM 2.5 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.

No abstract

In this study, particulate matter (PM) were characterized from a place impacted by heavy-duty vehicles (Bus Station) fuelled with diesel/biodiesel fuel blend (B3) in the city of Londrina, Brazil. Sixteen priority polycyclic aromatic hydrocarbons (PAH) concentrations were analyzed in the samples by their association with atmospheric PM, mass size distributions and major ions (fluorite, chloride, bromide, nitrate, phosphate, sulfate, nitrite, oxalate; fumarate, formate, succinate and acetate; lithium, sodium, potassium, magnesium, calcium and ammonium). Results indicate that major ions represented 21.2% particulate matter mass. Nitrate, sulfate, and ammonium, respectively, presented the highest concentration levels, indicating that biodiesel may also be a significant source for these ions, especially nitrate. Dibenzo[a,h]anthracene and indeno[1,2,3,-cd]pyrene were the main PAH found, and a higher fraction of PAH particles was found in diameters lower than 0.25 μm in Londrina bus station. The fine and ultrafine particles were dominant among the PM evaluated, suggesting that biodiesel decreases the total PAH emission. However, it does also increase the fraction of fine and ultrafine particles when compared to diesel.

Two campaigns were conducted in 2003 and 2004 at sites of different characteristics in São Paulo State. Atmospheric samples were collected twice a month during a 1-year campaign (an extensive campaign) from April 2003 to May 2004 at São Paulo City (SPA) site.The results showed that the pollutant concentrations were controlled not only by local source emissions but also through pollutant transport, both of which were dictated by the prevailing meteorological conditions. Chrysene, benzo(e)pyrene, and benzo(b)fluoranthene were the major compounds found, and diagnostic ratios indicated the multiplicity of sources: industrial, vehicular emission, and atmospheric transport. Intensive campaign (from July 15 to 30, 2003) samples showed higher cancer risk than those collected in the extensive campaign. Samples collected at the urban site (SPA) presented comparable values of PM 10 to the urban site influenced by sugarcane burning (Araraquara, ARQ). On the other hand, PAH average concentrations were higher at SPA than at other sites. In both campaigns, the highest value for dry atmospheric deposition flux was found in autumn and winter. Individually, BPe presented the highest deposition flux followed by BbF in the intensive campaign. It seems that during those periods, the dry deposition was the main airborne PAH removal mechanism. Diagnostic ratios suggested also vehicular emissions at the sites and photochemical reactions influencing in the atmospheric particulate matter composition. SPA and PRB samples presented higher cancer risk than ARQ in the intensive campaign.