Airborne particles in the Brazilian city of São Paulo: One-year investigation for the chemical composition and source apportionment
Guilherme Martins Pereira1,4, Kimmo Teinilä2, Danilo Custódio1,3, Aldenor Gomes Santos4, Huang Xian5, Risto Hillamo2, Célia A. Alves3, Jailson Bittencourt de Andrade4,6,7, Gisele Olímpio da Rocha4,6,7, Prashant Kumar8,9, Rajasekhar Balasubramanian5, Maria de Fátima Andrade10, and Pérola de Castro Vasconcellos1,41Institute of Chemistry, University of São Paulo, São Paulo – SP, 05508-000, Brazil 2Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland 3CESAM & Department of Environment, University of Aveiro, Aveiro, 3810-193, Portugal 4INCT for Energy and Environment, Federal University of Bahia, Salvador – BA, 40170-115, Brazil 5Department of Civil and Environmental Engineering, National University of Singapore, E1A 07-03, 117576, Singapore 6CIEnAm, Federal University of Bahia, Salvador – BA, 40170-115, Brazil 7Institute of Chemistry, Federal University of Bahia, Salvador – BA, 40170-115, Brazil 8Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom 9Environmental Flow Research Centre, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom 10Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, São Paulo – SP, 05508-090, Brazil
Abstract. São Paulo in Brazil has relatively relaxed regulations for ambient air pollution standards and often experiences high air pollution levels due to emissions of airborne particles from local sources and long-range transport of biomass burning-impacted air masses. In order to evaluate the sources of particulate air pollution (PM) and related health risks, a year-round sampling was performed for PM2.5 (≤ 2.5 μm) and PM10 (≤ 10 μm) in 2014 through intensive (every day sampling in wintertime) and extensive campaigns (once a week for the whole year) with 24 h of sampling. This year was characterized to have lower average precipitation comparing to meteorological data, and high pollution episodes were observed all year round, with a significant increase of pollution level in the intensive campaign, which was performed during wintertime. Different chemical constituents, such as carbonaceous species, polycyclic aromatic hydrocarbons (PAHs) and derivatives, water-soluble ions and biomass burning tracers were identified in order to evaluate health risks and to apportion sources. The species such as PAHs, inorganic and organic ions and monosaccharides were determined by chromatographic techniques and carbonaceous species by thermal-optical analysis. The associated risks to particulate matter exposure based on PAH concentrations were also assessed, along with indexes such as the benzo[a]pyrene equivalent (BaPE) and lung cancer risk (LCR). High BaPE and LCR were observed in most of the samples, rising to critical values in the wintertime. Also, biomass burning tracers and PAHs were higher in this season, while secondarily formed ions presented low variation throughout the year. Meanwhile, vehicular tracer species were also higher in the intensive campaign suggesting the influence of lower dispersion conditions in that period. Source apportionment was done by Positive Matrix Factorization (PMF), which indicated five different factors: road dust, industrial emissions, vehicular exhaust, biomass burning and secondary processes. The results highlighted the contribution of vehicular emissions and the significant input from biomass combustion in wintertime, suggesting that most of the particulate matter is due to local sources, besides the influence of pre-harvest sugarcane burning.
Martins Pereira, G., Teinilä, K., Custódio, D., Gomes Santos, A., Xian, H., Hillamo, R., Alves, C. A., Bittencourt de Andrade, J., Olímpio da Rocha, G., Kumar, P., Balasubramanian, R., de Fátima Andrade, M., and de Castro Vasconcellos, P.: Airborne particles in the Brazilian city of São Paulo: One-year investigation for the chemical composition and source apportionment, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-317, in review, 2017.