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Dominutti P, Nogueira T, Fornaro A, Borbon A. One decade of VOCs measurements in São Paulo megacity: Composition, variability, and emission evaluation in a biofuel usage context. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139790. [PMID: 32559485 DOI: 10.1016/j.scitotenv.2020.139790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
In South America, the observations of atmospheric pollutants are deficient, and few cities have implemented air quality monitoring programs. In addition, Volatile Organic Compounds (VOCs) observations are still missing, and little is known about their contributions to the atmospheric composition and impacts in a large ethanol usage context like Brazil. Here, we present a wide range of VOCs that have been measured for ten years in São Paulo Megacity (SPM) in different campaigns at traffic, urban and background sites. When compared with other cities worldwide, the average VOCs ambient concentrations in SPM were higher by factors of 2 to 10. However, the ambient VOCs distribution among these cities is homogeneous even for ethanol, aldehydes and alkenes species. Emission ratios (ER) were established related to carbon monoxide and acetylene, which did not depict strong seasonal and interannual variability in SPM. When compared with previous studies, ERs showed an enrichment from road-tunnel to background, suggesting the presence of other sources than traffic. A good agreement in ER was found with Los Angeles and Paris; but limited consistencies with Middle East and Asia cities. Our ethanol measurements show that contrasted ER can be obtained depending on the emission process involved, with a strong impact of evaporation on ethanol concentrations. The multiyear acetaldehyde analysis displayed that ER could be a valuable metric to assess the long-term changes in emissions sources. Finally, VOCs emissions were calculated from ER and compared with those estimated by the global emission inventory (Edgar). The total VOC emissions estimated by the global inventory agree very well with those from our observations up to 75%. Nevertheless, the VOCs speciation is misrepresented in the inventory, mainly for oxygenated and heavier alkanes compounds. These inconsistencies will also have an impact on the quantification of secondary atmospheric pollutants formation associated to road transport emissions.
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Affiliation(s)
- Pamela Dominutti
- Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo (IAG-USP), São Paulo, Brazil; Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK; Laboratoire de Météorologie Physique, LaMP-UMR 6016, CNRS, Université Clermont Auvergne, 63178 Aubière, France.
| | - Thiago Nogueira
- Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo (IAG-USP), São Paulo, Brazil; Departamento de Saúde Ambiental, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil
| | - Adalgiza Fornaro
- Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo (IAG-USP), São Paulo, Brazil
| | - Agnès Borbon
- Laboratoire de Météorologie Physique, LaMP-UMR 6016, CNRS, Université Clermont Auvergne, 63178 Aubière, France
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Dunmore RE, Whalley LK, Sherwen T, Evans MJ, Heard DE, Hopkins JR, Lee JD, Lewis AC, Lidster RT, Rickard AR, Hamilton JF. Atmospheric ethanol in London and the potential impacts of future fuel formulations. Faraday Discuss 2016; 189:105-20. [DOI: 10.1039/c5fd00190k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
There is growing global consumption of non-fossil fuels such as ethanol made from renewable biomass. Previous studies have shown that one of the main air quality disadvantages of using ethanol blended fuels is a significant increase in the production of acetaldehyde, an unregulated and toxic pollutant. Most studies on the impacts of ethanol blended gasoline have been carried out in the US and Brazil, with much less focus on the UK and Europe. We report time resolved measurements of ethanol in London during the winter and summer of 2012. In both seasons the mean mixing ratio of ethanol was around 5 ppb, with maximum values over 30 ppb, making ethanol currently the most abundant VOC in London air. We identify a road transport related source, with ‘rush-hour’ peaks observed. Ethanol is strongly correlated with other road transport-related emissions, such as small aromatics and light alkanes, and has no relationship to summer biogenic emissions. To determine the impact of road transport-related ethanol emission on secondary species (i.e. acetaldehyde and ozone), we use both a chemically detailed box model (incorporating the Master Chemical Mechanism, MCM) and a global and nested regional scale chemical transport model (GEOS-Chem), on various processing time scales. Using the MCM model, only 16% of the modelled acetaldehyde was formed from ethanol oxidation. However, the model significantly underpredicts the total levels of acetaldehyde, indicating a missing primary emission source, that appears to be traffic-related. Further support for a primary emission source comes from the regional scale model simulations, where the observed concentrations of ethanol and acetaldehyde can only be reconciled with the inclusion of large primary emissions. Although only constrained by one set of observations, the regional modelling suggests a European ethanol source similar in magnitude to that of ethane (∼60 Gg per year) and greater than that of acetaldehyde (∼10 Gg per year). The increased concentrations of ethanol and acetaldehyde from primary emissions impacts both radical and NOx cycling over Europe, resulting in significant regional impacts on NOy speciation and O3 concentrations, with potential changes to human exposure to air pollutants.
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Affiliation(s)
| | - Lisa K. Whalley
- School of Chemistry
- University of Leeds
- Leeds
- UK
- National Centre for Atmospheric Science
| | - Tomás Sherwen
- Wolfson Atmospheric Chemistry Laboratory
- University of York
- York
- UK
| | - Mathew J. Evans
- Wolfson Atmospheric Chemistry Laboratory
- University of York
- York
- UK
- National Centre for Atmospheric Science
| | - Dwayne E. Heard
- School of Chemistry
- University of Leeds
- Leeds
- UK
- National Centre for Atmospheric Science
| | - James R. Hopkins
- Wolfson Atmospheric Chemistry Laboratory
- University of York
- York
- UK
- National Centre for Atmospheric Science
| | - James D. Lee
- Wolfson Atmospheric Chemistry Laboratory
- University of York
- York
- UK
- National Centre for Atmospheric Science
| | - Alastair C. Lewis
- Wolfson Atmospheric Chemistry Laboratory
- University of York
- York
- UK
- National Centre for Atmospheric Science
| | | | - Andrew R. Rickard
- Wolfson Atmospheric Chemistry Laboratory
- University of York
- York
- UK
- National Centre for Atmospheric Science
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Galbán J, Andreu Y, Sierra JF, de Marcos S, Castillo JR. Intrinsic fluorescence of enzymes and fluorescence of chemically modified enzymes for analytical purposes: a review. LUMINESCENCE 2001; 16:199-210. [PMID: 11312548 DOI: 10.1002/bio.633] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In recent years our research group has developed new alternatives for fluorescence enzymatic determinations. First, we observed that the intrinsic fluorescence of enzymes changes during enzymatic reactions, proportionally to the substrate concentration, avoiding the combination of the enzymatic reaction with a fluorophore-involving reaction. The main disadvantage of this method is that the excitation and emission wavelengths of the enzymes are in the UV region of the spectrum. An alternative to overcome this problem consisted of covalently bonding the enzyme to a fluorophore. In this paper, an overview is given of all of the applications and future developments on both types of alternatives that we have developed. Apart from the analytical characteristics of the methods, we have also reviewed all of the information about mathematical models we have elaborated to date.
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Affiliation(s)
- J Galbán
- Analytical Spectroscopy and Sensors Group (GEAS), Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, -E-50009 Zaragoza, Spain.
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