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

Brito, Joel; Wurm, Florian Μ.; Yáñez‐Serrano, Ana María; Assunção, João Vicente de; Godoy, José Marcus; Artaxo, Paulo

doi:10.1021/acs.est.5b03281

Cited by 65 publications

(59 citation statements)

References 41 publications

(74 reference statements)

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“…At an urban site, the non-anthropogenic contribution is dominated by biogenic emissions and/or secondary formation in the atmosphere [Brito et al, 2015]. The method for the quantification has been explained in detail by Reimann et al [2000].…”

Section: Estimate Of Anthropogenic Contributionmentioning

confidence: 99%

Source identification of VOCs at an urban site of western India: Effect of marathon events and anthropogenic emissions

2016

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Ambient volatile organic compounds (VOCs) were measured using a high-resolution proton transfer reaction-time of flight-mass spectrometer at an urban site of Ahmedabad in India during the winter season in 2014. Mixing ratios of VOCs show large diurnal and day-to-day variations. Although strongly influenced by local emissions, periods of higher VOCs were observed during transport from the polluted Indo-Gangetic Plains than those from the cleaner Thar Desert. However with different rates, VOCs decreased exponentially with increasing wind speed. Relative abundance of methanol varied with weather conditions contributing highest and lowest under fog and clear-sky conditions, respectively. Among the compounds reported here, oxygenated VOCs (OVOCs) contribute to a large fraction (67-85%) with methanol being most abundant (40-58%). In spite of predominant vehicular emissions, diurnal distribution and emission ratios (ERs) of several VOCs indicate the role of biogenic and secondary sources. The ratios of isoprene/benzene and OVOCs/benzene show significant enhancements during daytime suggesting their contributions from biogenic and secondary sources. During marathon and cyclothon events, mixing ratios of VOCs were 2-10 times higher compared to a normal Sunday. The ERs of VOCs estimated using the nighttime data on marathon day are well within the range of values reported for several megacities of the world. The average contributions of primary anthropogenic sources to acetaldehyde, acetone, and isoprene were 44 ± 06%, 45 ± 07%, and 63 ± 12%, respectively. During cloudy condition, the increase in anthropogenic contribution to acetaldehyde (~10%), acetone (9%) and isoprene (30%) is due to reduction in biogenic emissions and secondary formation of these VOCs.

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Section: Estimate Of Anthropogenic Contributionmentioning

confidence: 99%

Source identification of VOCs at an urban site of western India: Effect of marathon events and anthropogenic emissions

2016

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“…Terrestrial vegetation (BrachoNunez et al, 2013;Brilli et al, 2014;Davison et al, 2008;De Gouw et al, 1999;Isidorov et al, 1985;Jardine et al, 2010;Kirstine et al, 1998;König et al, 1995;McKinney et al, 2011;Ruuskanen et al, 2011;Song and Ryu, 2013;Steeghs et al, 2004;Wilkins, 1996;, fungi (Wheatley et al, 1997) and bacteria (Song and Ryu, 2013;Wilkins, 1996) are known to emit MEK. It is also emitted directly by several anthropogenic sources, including anthropogenic biomass burning (Andreae and Merlet, 2001), solvent evaporation (Kim et al, 2015;Legreid et al, 2007) and vehicle exhaust (Bon et al, 2011;Brito et al, 2015;Liu et al, 2015;Verschueren, 1983). In addition, MEK can be formed via the atmospheric oxidation of other compounds (de Gouw et al, 2003;Jenkin et al, 1997;Neier and Strehlke, 2002;Sommariva et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Atmospheric mixing ratios of methyl ethyl ketone (2-butanone) in tropical, boreal, temperate and marine environments

et al. 2016

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Abstract. Methyl ethyl ketone (MEK) enters the atmosphere following direct emission from vegetation and anthropogenic activities, as well as being produced by the gas-phase oxidation of volatile organic compounds (VOCs) such as nbutane. This study presents the first overview of ambient MEK measurements at six different locations, characteristic of forested, urban and marine environments. In order to understand better the occurrence and behaviour of MEK in the atmosphere, we analyse diel cycles of MEK mixing ratios, vertical profiles, ecosystem flux data, and HYSPLIT back trajectories, and compare with co-measured VOCs. MEK measurements were primarily conducted with protontransfer-reaction mass spectrometer (PTR-MS) instruments. Results from the sites under biogenic influence demonstrate that vegetation is an important source of MEK. The diel cycle of MEK follows that of ambient temperature and the forest structure plays an important role in air mixing. At such sites, a high correlation of MEK with acetone was observed (e.g. r 2 = 0.96 for the SMEAR Estonia site in a remote hemiboreal forest in Tartumaa, Estonia, and r 2 = 0.89 at the ATTO pristine tropical rainforest site in central Amazonia). Under polluted conditions, we observed strongly enhanced MEK mixing ratios. Overall, the MEK mixing ratios and flux data presented here indicate that both biogenic and anthropogenic sources contribute to its occurrence in the global atmosphere.

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“…Furthermore, ratios to CO are regularly reported in the literature for biomass burning and urban emissions (Baker et al, 2008;Borbon et al, 2013;Brito et al, 2015;Gilman et al, 2015;de Gouw et al, 2017;Koss et al, 2018;Wang 245 et al, 2014), which can be useful for further comparisons. Emission ratios were calculated in ppbv of VOC per ppmv of CO, which is similar to a molar ratio (mmol VOC per mol CO).…”

Section: Emission Ratiosmentioning

confidence: 98%

Anthropogenic VOC in Abidjan, southern West Africa: from source quantification to atmospheric impacts

Dominutti¹,

Keita²,

Bahino³

et al. 2018

Preprint

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Several field campaigns were deployed in the framework of the project Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) to measure a broad range of atmospheric constituents. Here, we present the 20 analysis of an unprecedented and comprehensive dataset integrating up to fifty-six VOC from ambient sites and emission sources. VOCs were collected on sorbent tubes in the coastal city of Abidjan, Côte d'Ivoire, in winter and summer 2016 and analysed by gas chromatography coupled with flame ionization and mass spectrometer detectors (GC-FID and GC-MS) at the laboratory.The comparison between VOC emission source profiles and ambient profiles suggests the substantial impact of two-25 wheelers and domestic fires on the composition of Abidjan's atmosphere. However, despite the high VOC concentrations near-source, moderate ambient levels were observed (by a factor of 10 to 4000 lower) and similar to the ones observed in northern mid-latitude urban areas. Beyond photochemistry, reported high wind speeds suggest that meteorology is an essential factor that regulates air pollution in Abidjan.Emission ratios (VOC/CO) were established based on real-world measurements achieved on a selected number of 30 representative combustion sources. Maximal molar mass contributions were observed from two-wheeler (TW) emissions, overpassing other regional sources by two orders of magnitude. This source also largely governs the VOC atmospheric impacts in terms of OH reactivity, secondary aerosol formation (SOAP) and ozone production (POCP).While the contribution of aromatics dominates the atmospheric impact, our measurements reveal the systematic presence of anthropogenic terpenoids in all residential combustion sectors. Finally, emission factors were used to 35 retrieve and quantify VOC emissions from the main anthropogenic source sectors at national level. Our detailed VOC emissions estimation suggests that the road transport sector is the dominant source in Cote d'Ivoire by emitting Atmos. Chem. Phys. Discuss., https://doi.around 1200 Gg yr −1 of gas-phase VOCs. These new estimations are 100 and 160 times larger than previous global inventory estimations like MACCity or Edgar (v4.3.2). Additionally, the residential sector is also largely underestimated by a factor of 13 to 43. For the only Cote d'Ivoire, these new estimates for VOCs are three to six 40 times higher than the whole Europe. Given the significant underestimation of VOC emissions from transport and residential sectors for Côte d'Ivoire country there is an urgent need for such an effort in the whole West Africa region for building more realistic and region-specific emission inventories. This is not only true for VOCs but all atmospheric pollutants. The dearth of waste burning, fuelwood burning and charcoal representation in regional inventories need also to be addressed, particularly in low-income areas where these types of activities are essential 45 sources of VOC emissions.

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

Cited by 65 publications

References 41 publications

Source identification of VOCs at an urban site of western India: Effect of marathon events and anthropogenic emissions

Source identification of VOCs at an urban site of western India: Effect of marathon events and anthropogenic emissions

Atmospheric mixing ratios of methyl ethyl ketone (2-butanone) in tropical, boreal, temperate and marine environments

Anthropogenic VOC in Abidjan, southern West Africa: from source quantification to atmospheric impacts

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