title: Intra-urban biomonitoring: Source apportionment using tree barks to identify air pollution sources.
abstract: It is of great interest to evaluate if there is a relationship between possible sources and trace elements using biomonitoring techniques. In this study, tree bark samples of 171 trees were collected using a biomonitoring technique in the inner city of São Paulo. The trace elements (Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, Rb, S, Sr and Zn) were determined by the energy dispersive X-ray fluorescence (EDXRF) spectrometry. The Principal Component Analysis (PCA) was applied to identify the plausible sources associated with tree bark measurements. The greatest source was vehicle-induced non-tailpipe emissions derived mainly from brakes and tires wear-out and road dust resuspension (characterized with Al, Ba, Cu, Fe, Mn and Zn), which was explained by 27.1% of the variance, followed by cement (14.8%), sea salt (11.6%) and biomass burning (10%), and fossil fuel combustion (9.8%). We also verified that the elements related to vehicular emission showed different concentrations at different sites of the same street, which might be helpful for a new street classification according to the emission source. The spatial distribution maps of element concentrations were obtained to evaluate the different levels of pollution in streets and avenues. Results indicated that biomonitoring techniques using tree bark can be applied to evaluate dispersion of air pollution and provide reliable data for the further epidemiological studies.
authors.affiliation: Medical School of São Paulo University (FMUSP), São Paulo, SP, Brazil; National Institute for Integrated Analysis of Environmental Risk (INAIRA), São Paulo, SP, Brazil.
authors.forename: Tiana Carla Lopes
authors.initials: TC
authors.lastname: Moreira
authors.affiliation: Medical School of São Paulo University (FMUSP), São Paulo, SP, Brazil; National Institute for Integrated Analysis of Environmental Risk (INAIRA), São Paulo, SP, Brazil.
authors.forename: Regiani Carvalho
authors.initials: RC
authors.lastname: de Oliveira
authors.affiliation: Medical School of São Paulo University (FMUSP), São Paulo, SP, Brazil; National Institute for Integrated Analysis of Environmental Risk (INAIRA), São Paulo, SP, Brazil.
authors.forename: Luís Fernando Lourenço
authors.initials: LF
authors.lastname: Amato
authors.affiliation: Harvard School of Public Health (HSPH), Boston, MA, USA.
authors.forename: Choong-Min
authors.initials: CM
authors.lastname: Kang
authors.affiliation: Medical School of São Paulo University (FMUSP), São Paulo, SP, Brazil; National Institute for Integrated Analysis of Environmental Risk (INAIRA), São Paulo, SP, Brazil.
authors.forename: Paulo Hilário Nascimento
authors.initials: PH
authors.lastname: Saldiva
authors.affiliation: Nuclear and Energy Research Institute (IPEN-CNEN/SP), São Paulo, SP, Brazil; National Institute for Integrated Analysis of Environmental Risk (INAIRA), São Paulo, SP, Brazil.
authors.forename: Mitiko
authors.initials: M
authors.lastname: Saiki
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D001938:Brazil; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D024301:Plant Bark / Q000737:chemistry*; D025341:Principal Component Analysis; D013052:Spectrometry, X-Ray Emission; D014131:Trace Elements / Q000032:analysis*; D014197:Trees; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000393:Air Pollutants; D014131:Trace Elements; D001335:Vehicle Emissions