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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Vehicular Emission Ratios of VOCs in a Megacity Impacted by Extensive Ethanol Use: Results of Ambient Measurements in Sao Paulo, Brazil

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Brito, Joel [1] ; Wurm, Florian [1] ; Yanez-Serrano, Ana Maria [2, 3] ; de Assuncao, Joao Vicente [4] ; Godoy, Jose Marcus [5] ; Artaxo, Paulo [1]
Total Authors: 6
[1] Univ Sao Paulo, Inst Phys, Sao Paulo - Brazil
[2] Max Planck Inst Chem, Biogeochem Dept, D-55128 Mainz - Germany
[3] Natl Inst Res Amazonia, Manaus, Amazonas - Brazil
[4] Univ Sao Paulo, Sch Publ Hlth, Sao Paulo - Brazil
[5] Pontifical Catholic Univ Rio de Janeiro, Dept Chem, Rio De Janeiro - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Environmental Science & Technology; v. 49, n. 19, p. 11381-11387, OCT 6 2015.
Web of Science Citations: 14

The Sao Paulo Metropolitan Area (SPMA) is a megacity with 20 million people and over 8 million vehicles. Over the past decade a large increase in biofuel usage, more notably ethanol by light-duty vehicles, has made Brazil, and in particular Sao Paulo, a unique case worldwide. This study presents the first assessment of emission ratios of a selected group of volatile organic compounds (VOCs) relative to carbon monoxide (CO) under ambient conditions. The VOCs studied here include aromatics such as benzene (1.03 pptv/ppbv CO), toluene (3.10 pptv/ppbv CO) and Oxygenated VOCs such as methanol (5.39 pptv/ppbv CO), acetaldehyde (3.93 pptv/ppbv CO), acetone (3.59 pptv/ppbv CO), methyl ethyl ketone (1.42 pptv/ppbv CO), and others. Despite the specificity of the fuel composition, emission ratios were in surprisingly close agreement with other megacities in Europe or in North America. Such results include species whose emission factors have been previously reported to decline (e.g., benzene) or increase (e.g., acetaldehyde) with ethanol usage. Furthermore, diurnal profiles and temperature analysis aid separating the primary anthropogenic, secondary or biogenic components of the species studied here. This study shows that a significant fraction of ethanol in gasoline blends does not result in a well-defined trend in VOC emission profile and certainly motivates further studies. (AU)

FAPESP's process: 13/25058-1 - Impact of Manaus urban pollution on gases and particulate matter composition in the Amazon forest
Grantee:Joel Ferreira de Brito
Support type: Scholarships in Brazil - Post-Doctorate