Spatial variation of roadside C2–C6 hydrocarbon concentrations during low wind speeds: A note

O’Donoghue, R.T.; Broderick, Brian

doi:10.1016/j.trd.2007.07.003

Cited by 5 publications

(4 citation statements)

References 7 publications

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“…Our analysis unit was one distance/concentration pair (e.g., a single CO measurement at 30 m from the edge of road). We identified 780 such pairs from 41 papers ,− ; the literature represents wide geographic, meteorological, and traffic operational variation. (The Supporting Information includes an annotated bibliography of all studies.…”

Section: Methodsmentioning

confidence: 99%

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Near-Roadway Air Quality: Synthesizing the Findings from Real-World Data

Karner

Eisinger

Niemeier

2010

Environ. Sci. Technol.

631

430

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Despite increasing regulatory attention and literature linking roadside air pollution to health outcomes, studies on near roadway air quality have not yet been well synthesized. We employ data collected from 1978 as reported in 41 roadside monitoring studies, encompassing more than 700 air pollutant concentration measurements, published as of June 2008. Two types of normalization, background and edge-of-road, were applied to the observed concentrations. Local regression models were specified to the concentration-distance relationship and analysis of variance was used to determine the statistical significance of trends. Using an edge-of-road normalization, almost all pollutants decay to background by 115-570 m from the edge of road; using the more standard background normalization, almost all pollutants decay to background by 160-570 m from the edge of road. Differences between the normalization methods arose due to the likely bias inherent in background normalization, since some reported background values tend to underpredict (be lower than) actual background. Changes in pollutant concentrations with increasing distance from the road fell into one of three groups: at least a 50% decrease in peak/edge-of-road concentration by 150 m, followed by consistent but gradual decay toward background (e.g., carbon monoxide, some ultrafine particulate matter number concentrations); consistent decay or change over the entire distance range (e.g., benzene, nitrogen dioxide); or no trend with distance (e.g., particulate matter mass concentrations).

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Section: Methodsmentioning

confidence: 99%

“…Monitored concentration data are typically normalized to wind speed or traffic volume , to a reference near-road distance , , or by subtracting out background concentration , . There are problems in normalizing to traffic volume or meteorological conditions when aggregating data across numerous studies.…”

Section: Methodsmentioning

confidence: 99%

Near-Roadway Air Quality: Synthesizing the Findings from Real-World Data

Karner

Eisinger

Niemeier

2010

Environ. Sci. Technol.

631

430

View full text Add to dashboard Cite

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“…As has been established previously (O'Donoghue & Broderick, 2005), this ratio is more useful in determining the extent of local traffic emission sources, rather than the extent of catalytic converter efficiency. We have ascertained that the higher the relative ethene/acetylene ratio obtained the nearer the road traffic emission source.…”

Section: Ethene/acetylene (E/a) Ratiomentioning

confidence: 96%

C2-C6 Background Hydrocarbon Concentrations Monitored at a Roof Top and Green Park Site, in Dublin City Centre

O’Donoghue

Broderick

2006

Environ Monit Assess

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A 5 week monitoring campaign was carried out in Dublin City centre, to establish which site gave a more accurate background city centre estimation: a roof-top or green field site. This background represented a conservative estimate of HC exposure in Dublin City centre, useful for quantifying health effects related to this form of pollution and also for establishing a local background relative to the four surrounding main roads when the wind direction is travelling towards each road with the background receptor upwind. Over the entire monitoring campaign, the lowest concentrations and relative standard deviations were observed at the green field site, regardless of time of day or meteorological effects.

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“…Many other VOCs besides the eight aromatics identified in this study are present in motor vehicle exhaust and likely taken up by travelers, but are difficult to use as breath biomarkers of exposure. Aromatics are often concentrated near roadways, , whereas alkanes tend to be more widely distributed due to nonroadway sources, and traffic-related aldehydes such as acetaldehyde and acrolein have large secondary components from oxidation of primary VOC emissions; acetaldehyde was poorly correlated with benzene in the ambient air sample data (see SI Table S4). Breath concentrations of alcohols, acetates, and ketones may be less representative of their respective blood concentrations than breath concentrations of BTEX and other aromatics due to greater solubility in water. − Some compounds have very low solubility in blood (e.g., short-chain alkanes), and so absorbed doses during riding might be too small to measurably change breath concentrations .…”

Section: Discussionmentioning

confidence: 99%

Breath Biomarkers to Measure Uptake of Volatile Organic Compounds by Bicyclists

Bigazzi

Figliozzi

Luo

et al. 2016

Environ. Sci. Technol.

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Breath biomarkers were used to study uptake of traffic-related volatile organic compounds (VOCs) from urban bicycling. Breath analysis was selected because it is one of the least invasive methods to assess urban traveler exposure. Research hurdles that were overcome included considering that factors other than on-road exposure can influence concentrations in the body, and absorbed doses during a trip can be small compared to baseline body burdens. Pre-trip, on-road, and post-trip breath concentrations and ambient air concentrations were determined for 26 VOCs for bicyclists traveling on different path types. Statistical analyses of the concentration data identified eight monoaromatic hydrocarbons potentially useful as breath biomarkers to compare differences in body levels brought about by urban travel choices. Breath concentrations of the biomarker compounds were significantly higher than background levels after riding on high-traffic arterial streets and on a path through a high-exposure industrial area, but not after riding on low-traffic local streets or on other off-street paths. Modeled effects of high-traffic streets on ambient concentrations were 100-200% larger than those of low-traffic streets; modeled effects of high-traffic streets on breath concentrations were 40-100% larger than those of low-traffic streets. Similar percentage increases in breath concentrations are expected for bicyclists in other cities.

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Spatial variation of roadside C2–C6 hydrocarbon concentrations during low wind speeds: A note

Cited by 5 publications

References 7 publications

Near-Roadway Air Quality: Synthesizing the Findings from Real-World Data

Near-Roadway Air Quality: Synthesizing the Findings from Real-World Data

C2-C6 Background Hydrocarbon Concentrations Monitored at a Roof Top and Green Park Site, in Dublin City Centre

Breath Biomarkers to Measure Uptake of Volatile Organic Compounds by Bicyclists

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