Respeciation of organic gas emissions and the detection of excess unburned gasoline in the atmosphere

Harley, Robert A.; Hannigan, Michael P.; Cass, Glen R.

doi:10.1021/es00036a010

Cited by 182 publications

(159 citation statements)

References 25 publications

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“…emissions of aromatic hydrocarbons [Harley et al, 1992;Grosjean et al, 2001;Kristensson et al, 2004]. The presently found emission ratios of OVOCs are much higher, suggesting that vehicles are not the dominant sources of OVOCs in urban areas.…”

Section: Sources and Chemistry Of Ovocsmentioning

confidence: 84%

“…Nevertheless, the contribution from diesel trucks to the total vehicle emissions is relatively small in the U.S. (4% [Kirchstetter et al, 1999]), which means that OVOC emission ratios averaged over the entire fleet will be close to those for gasoline-powered vehicles. Larger sources of OVOCs may include their use as solvent in coatings and adhesives [Harley et al, 1992]. It is also possible that the vegetation in cities, which is typically different from the surrounding areas, contributes to the emissions of species like methanol.…”

Section: Sources and Chemistry Of Ovocsmentioning

confidence: 99%

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Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002

et al. 2005

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[1] An extensive set of volatile organic compounds (VOCs) and particulate organic matter (POM) was measured in polluted air during the New England Air Quality Study in 2002. Using VOC ratios, the photochemical age of the sampled air masses was estimated. This approach was validated (1) by comparing the observed rates at which VOCs were removed from the atmosphere with the rates expected from OH oxidation, (2) by comparing the VOC emission ratios inferred from the data with the average composition of urban air, and (3) by the ability to describe the increase of an alkyl nitrate with time in terms of the chemical kinetics. A large part of the variability observed for oxygenated VOCs (OVOCs) and POM could be explained by a description that includes the removal of the primary anthropogenic emissions, the formation and removal of secondary anthropogenic species, and a biogenic contribution parameterized by the emissions of isoprene. The OVOC sources determined from the data are compared with the available literature, and a satisfactory agreement is obtained. The observed sub-mm POM was highly correlated with secondary anthropogenic gas-phase species, strongly suggesting that the POM was from secondary anthropogenic sources. The results are used to describe the speciation and total mass of gas-and particle-phase organic carbon as a function of the photochemical age of an urban air mass. Shortly after emission the organic carbon mass is dominated by primary VOCs, while after two days the dominant contribution is from OVOCs and sub-mm POM. The total measured organic carbon mass decreased by about 40% over the course of two days. The increase in sub-mm POM could not be explained by the removal of aromatic precursors alone, suggesting that other species must have contributed and/or that the mechanism for POM formation is more efficient than previously assumed.Citation: de Gouw, J. A., et al. (2005), Budget of organic carbon in a polluted atmosphere: Results from the New England Air

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Section: Sources and Chemistry Of Ovocsmentioning

confidence: 84%

Section: Sources and Chemistry Of Ovocsmentioning

confidence: 99%

Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002

et al. 2005

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“…A characterization of hydrocarbons, in particular, is important for an assessment of: human exposure to air toxics (Dann and Wang, 1992), the reactive potential of the urban mixture with respect to ozone formation, and more recently for the verification of HC emission inventories that are ultimately used in air quality management plans and photochemical modelling (Harley et al, 1992).…”

mentioning

confidence: 99%

“…This source-receptor modelling approach has been applied in a number of urban source apportionment studies with the intention of reconciling emissions inventories with ambient measurements (Aronian et aI., 1989;Harley et al, 1992;Kenski et al, 1993). CMB modelling has also been applied specifically to the apportionment of mobile source VOCs to tailpipe and non-tailpipe sources from ambient air and tunnel samples (Gertler et ai" 1993;Lin and Milford, 1993).…”

mentioning

confidence: 99%

Analysis of motor vehicle sources and their contribution to ambient hydrocarbon distributions at urban sites in Toronto during the Southern Ontario oxidants study

McLaren¹,

Singleton²,

Lai³

et al. 1996

Atmospheric Environment

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Abstract-Hydrocarbon distributions measured in the urban area of Toronto during the Southern Ontario Oxidants Study of 1992 are presented. Comparison is made to hydrocarbon distributions measured in other urban areas. Relative concentrations of olefins were found to be depleted aloft compared to the surface level measurements. Chemical mass balance modelling was used to apportion the measured hydrocarbon distributions at York University and other roadside sites to gasoline based sources. The most dominant contributing source was vehicle exhaust. The relative amount of unburned gasoline at York University was found to be significant in the summer, and higher than that observed there during the winter or at other roadside sites. The relative amount of evaporative emissions (gasoline vapour) apportioned by the CMB model at roadside sites was compared to evaporative emissions predicted by a mobile emission factor model, MOBILESC. The percentage-of-gasoline-based non-methane-hydroearbons (NM-He) apportiorre-d to gasoline vapour by the CMB model was equivalent within error to the relative amount of evaporative NMHC predicted by the MOBILE5C model for summer temperatures. For winter temperatures, the MOBILE5C model predicted significantly less evaporative emissions than that apportioned by the CMB model. An anthropogenic souroe of isoprene in the urban area has been proposed and tested. The inclusion of an isoprene flux in the exhaust source profile, consistent with that measured in the Auto/Oil Air Quality Improvement Research Program, results in calculated isoprene concentrations that are in agreement with observed concentrations at roadside' sites and at York University in the winter. During summer, the combustion related isoprene can only account for a small fraction of the observed isoprene at downtown sites and at York University, at most 20%.. . .

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“…bAir basin-wide mass emission rates in the South Coast Air Basin that surrounds Los Angeles for 27 August 1987 (8). cRank is determined from the product of Bayes' probability value (see Table 2) x MC units (potency) x atmospheric concentration.…”

Section: Methodsmentioning

confidence: 99%

Prioritizing testing of organic compounds detected as gas phase air pollutants: structure-activity study for human contact allergens.

Johnson

Macina

Graham

et al. 1997

Environ Health Perspect

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Organit compounds that are used or gend anthropogenically in Lag quantities i cities call be identified through their presence in the urban atmosphere and in air pollutant source enissions. Compounds ideqtified by this method were screned to evauate their potental to ac as contact allergens. The CASE and MULTICASE computer programs, which are based on the detection of structure-aciity relationships (SAl), were used to evaluate this potential. These relationships first are dte ed by comparing chemial stctures to biological activity within a learning set comprised of 458 compounds, each of which had been tested experimentally in human trials for its sensitization potential. Using the inormation contained in this learning set, CASE and MULTiCASE predicted! the activity of 238 comp found. in-the atmosphere for their ability to act as contact allergens. The analysis finds that 21 of 238 compounds are predicted to be active contact aIlergens (probability >0.5), with potencies rnging fiom mild to very strong. The compounds come from chemical dames that indude chlorinated aromatics and chiorinated hydrocarbons, N-containing compounds, phenols, alienes, and an S&containing compound. U,sig the measured airborne concentrations or emission rates of these compounds as an indication of the extent oftheir use, together with their predicted potencies, provides an efficient methed to prioritize the expeimental assessment of contact sensitization of untested organic compounds that can be detectd as air pollutants.

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Respeciation of organic gas emissions and the detection of excess unburned gasoline in the atmosphere

Cited by 182 publications

References 25 publications

Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002

Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002

Analysis of motor vehicle sources and their contribution to ambient hydrocarbon distributions at urban sites in Toronto during the Southern Ontario oxidants study

Prioritizing testing of organic compounds detected as gas phase air pollutants: structure-activity study for human contact allergens.

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