Characterization of non-methane hydrocarbons in the rural southeast United States

Hagerman, Lisa M.; Aneja, Viney P.; Lonneman, William A.

doi:10.1016/s1352-2310(97)00223-9

Cited by 98 publications

(83 citation statements)

References 28 publications

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“…This may indicate that the local emissions at PNTX were significantly reduced in winter. This result is in agreement with the previous concentration-temperature correlation analysis, and it is also in agreement with literature results (Hagerman et al, 1997).…”

Section: Seasonal Variationssupporting

confidence: 94%

“…Because total emissions from motor vehicles in an urban area do not vary significantly from day to day, factors other than emissions from motor vehicles contribute to the observed seasonal changes in urban air pollution. For instance, higher concentrations of hydrocarbons during the winter months are consistent with the effects of photochemical reactions, which are known to consume airborne hydrocarbons, especially in the summer (Hagerman et al, 1997). Further, the seasonal trends for hydrocarbons also can be explained by emissions from home heating sources (e.g., fireplaces, wood-burning stoves), which are notably higher during the winter months, especially for locations with cold temperatures (e.g., Vermont).…”

Section: Correlations Between Concentrations and Temperaturementioning

confidence: 66%

“…Cancer is one health effect of wide concern; others include birth defects, damage to the immune and nervous systems, and other fatal diseases (Singh et al, 1982;Kao, 1994). Recently, a number of volatile organic compounds (VOCs) have been identified as important cancer risk factors in the urban environment (Hagerman et al, 1997). These compounds (VOCs) are not routinely monitored in urban air, and no ambient air quality standards have yet been established for them.…”

Section: Introductionmentioning

confidence: 99%

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Volatile organic compounds in some urban locations in United States

2002

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Importance of this paper: Air pollution in urban locations contains many components that originate from a wide range of industrial, motor vehicle, and natural emissions sources. Some of these components include compounds known or suspected to be carcinogenic, and some of them play important roles in atmospheric chemistry such as tropospheric ozone pollution and stratospheric ozone depletion. Therefore, it is essential to characterize the composition, magnitude, and the distribution of urban air pollution through extensive ambient air monitoring and assess the impact of these components on human health and global atmospheric chemistry. AbstractVolatile organic compounds (VOCs) have been determined to be human risk factors in urban environments, as well as primary contributors to the formation of photochemical oxidants. Ambient air quality measurements of 54 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in or near 13 urban locations in the United States during September 1996 to August 1997. Air samples were collected and analyzed in accordance with US Environmental Protection Agency-approved methods. The target compounds most commonly found were benzene, toluene, xylene and ethylbenzene. These aromatic compounds were highly correlated and proportionally related in a manner suggesting that the primary contributors were mobile sources in all the urban locations studied. Concentrations of total hydrocarbons ranged between 1.39 and 11.93 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations, and no single factor seemed to explain trends for this group of compounds. The highest halogenated hydrocarbon concentrations ranged from 0.24 ppbv for methylene chloride to 1.22 ppbv for chloromethane. At participating urban locations for the year of data considered, levels of carbonyls were higher than the level of the other organic compound groups, suggesting that emissions from motor vehicles and photochemical reactions strongly influence ambient air concentrations of carbonyls. Of the most prevalent carbonyls, formaldehyde and acetaldehyde were the dominant compounds, ranging from 1.5-7.4 ppbv for formaldehyde, to 0.8-2.7 ppbv for acetaldehyde. Ó

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Section: Seasonal Variationssupporting

confidence: 94%

Section: Correlations Between Concentrations and Temperaturementioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

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Volatile organic compounds in some urban locations in United States

2002

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“…The atmospheric chemistry of these biogenic VOCs has received particular attention because of the large quantities emitted globally in comparison with the release of anthropogenic VOCs and the high reactivity of the mostly unsaturated biogenic VOCs Simpson et al, 1995]. For example, there is substantial evidence that biogenic hydrocarbons influence the regional distribution of ozone [Hagerman et al, 1997;Simpson, 1995]. However, one of the major uncertainties of the impact of biogenic hydrocarbons on atmospheric processes is the quantitative understanding of their ability to form organic aerosols.…”

Section: Introductionmentioning

confidence: 99%

Molecular composition of organic aerosols formed in the α‐pinene/O₃ reaction: Implications for new particle formation processes

Hoffmann¹,

Bandur²,

Marggraf³

et al. 1998

J. Geophys. Res.

234

231

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Abstract. The molecular composition of particle phase ozonolysis products of o•-pinene is investigated to comprehend the aerosol formation process following the VOC oxidation, focusing on an understanding of new particle formation. Two analytical approaches are applied to identify lowvolatile oxidation products in the particle phase; off-line investigations using preconcentration on Tenax TA © followed by solvent extraction and liquid chromatography/mass spectrometry as well as an on-line technique, in which the organic aerosols are introduced directly into the ion source of a mass spectrometer (atmospheric pressure chemical ionization / mass spectrometry (APCI/MS)). Both techniques showed the formation of difunctional carboxylic acids, compounds whose physico-chemical properties will govern most of their mass into the particle phase. Furthermore, stable binary diacid adducts could be identified by MSn-experiments. These observations might give insight into the process of new particle formation by heteromolecular homogeneous nucleation, indicating that the initial cluster formation cannot be described by macroscopic properties of single oxidation products. Instead, strong intermolecular forces between different diacids might play a key role in the formation of initial nuclei and their subsequent growth.

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“…Emissions of NH 3 (Aneja et al, 2000), NO (Aneja et al, 2001c), Isoprene (Hagerman et al, 1997), and H 2 S (Hill et al, 1978), respectively, versus Temperature at various locations.…”

Section: The Graphs Inmentioning

confidence: 99%

Dynamic Chamber System to Measure Gaseous Compounds Emissions and Atmospheric-Biospheric Interactions

Aneja

Blunden

Claiborn

et al.

Nato Science Series: IV: Earth and Environmental Science

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The dynamic flow-through chamber system has been developed in response to a need to measure emissions of nitrogen, sulphur, and carbon compounds for a variety of field applications. The cylindrical chamber system is constructed of chemically inert materials and internally lined with 5mil thick transparent fluorinated ethylene polypropylene (FEP) Teflon to reduce chemical reactions and build up of temperature inside the chamber. The chamber (diameter = 27cm, height = 42 cm, volume = 24.05 L) is designed with an open-ended bottom that can penetrate either soil or liquid to a depth of ~6-8 cm, thus creating a completely enclosed system. Carrier gas (e.g. compressed zero-grade air) is pumped at a constant flow rate (~2 to ~5 lpm), depending on the season. The air inside the chamber is well mixed by a variable-speed, motor-driven Teflon impeller (~40 to ~100 rpm). Many different laboratory and field experiments have been conducted using this dynamic chamber system. Oxides of nitrogen (NO, NO 2 , NO y ) emissions have been measured from agricultural soils where nitrogen-rich fertilizers have been applied. Ammonia-nitrogen (NH 3 -N) and reduced organic sulphur compounds emissions have been measured using this same technique across a gas-liquid interface at swine waste treatment anaerobic storage lagoons, and agricultural fields. Similar chamber systems have also been deployed to measure uptake of nitrogen, sulphur, ozone, and hydrogen peroxide gases by crops and vegetation to examine atmospheric-biospheric interactions. Emissions measurements have been validated by a coupled gas-liquid transfer with chemical reaction model as well as a U.S. Environmental Protection Agency (EPA) WATER 9 model.

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Characterization of non-methane hydrocarbons in the rural southeast United States

Cited by 98 publications

References 28 publications

Volatile organic compounds in some urban locations in United States

Volatile organic compounds in some urban locations in United States

Molecular composition of organic aerosols formed in the α‐pinene/O₃ reaction: Implications for new particle formation processes

Dynamic Chamber System to Measure Gaseous Compounds Emissions and Atmospheric-Biospheric Interactions

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Characterization of non-methane hydrocarbons in the rural southeast United States

Cited by 98 publications

References 28 publications

Volatile organic compounds in some urban locations in United States

Volatile organic compounds in some urban locations in United States

Molecular composition of organic aerosols formed in the α‐pinene/O3 reaction: Implications for new particle formation processes

Dynamic Chamber System to Measure Gaseous Compounds Emissions and Atmospheric-Biospheric Interactions

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Molecular composition of organic aerosols formed in the α‐pinene/O₃ reaction: Implications for new particle formation processes