Characterization of Fine Particle and Gaseous Emissions during School Bus Idling

Kinsey, John S.; Williams, D. C.; Dong, Yuanji; Logan, Russell

doi:10.1021/es0625024

Cited by 20 publications

(13 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This increase in the level of PM 2.5 and UFP during operating hours was attributable to emissions from diesel buses. Kinsey et al (2007) demonstrated that PM 2.5 emissions from buses were generally higher during continuous idle compared to post-restart. The restart and immediate departure of buses demonstrated the lowest emissions of PM 2.5 .…”

Section: Introductionmentioning

confidence: 97%

“…Bus stations often present high concentrations of PM released as a result of the incomplete combustion of fuel when buses decelerate, idle and accelerate (Yip et al, 2006;Kinsey et al, 2007;Jayaratne et al 2009;Richmond-Bryant et al, 2009;Wang et al, 2010). See et al (2006) showed that average levels of PM 2.5 and UFP in a major bus interchange increased by a factor of 2.3 and 5.1, respectively, during operating hours compared to non-operating hours.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Temporal Variations in Airborne Particulate Matter Levels at an Indoor Bus Terminal and Exposure Implications for Terminal Workers

Chen

Chang

Yan

2012

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

This study investigates temporal variations in PM levels in Taipei bus terminal and assesses exposure levels for bus terminal workers. Measurement results show that temporal variations in PM levels in the waiting room and on the platform of this indoor bus terminal were strongly associated with bus traffic volume. The PM 10 , PM 2.5 , and ultrafine particle (UFP) levels on the bus platform were 1.9, 2.0, and 1.2 times higher than those inside the waiting room, respectively. Additionally, PM 10 and PM 2.5 levels on the platform were approximately 2.3 and 2.8 times higher than those at an ambient monitoring station, respectively. Measurement results indicate that the major PM source inside this bus terminal is diesel buses and that PM can be trapped in this semi-confined bus terminal to a far greater extent than in typical open-air bus stations. Daily PM exposure levels for station ticket inspectors who check passenger tickets in the waiting room and manage arriving and departing buses on the bus platform are assessed. Daily PM exposure levels for station ticket inspectors during different shifts are calculated based on average PM levels and working time spent in the waiting room and on the platform. Based on observational results, station ticket inspectors spend approximately 80-85% and 15-20% of their working time in the waiting room and on the platform, respectively. Daily PM 10 and PM 2.5 exposure levels for station ticket inspectors were approximately 1.3-1.5 and 1.6-1.8 times higher than those in the outdoor atmosphere, respectively. Additionally, daily UFP exposure levels for station ticket inspectors were approximately 5.6-7.2 times higher than those in the urban background. Measurement results demonstrate that potential health risk induced by PM is high for station ticket inspectors who work for long periods at this indoor bus terminal.

show abstract

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Temporal Variations in Airborne Particulate Matter Levels at an Indoor Bus Terminal and Exposure Implications for Terminal Workers

Chen

Chang

Yan

2012

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

show abstract

“…The wake of a moving vehicle could significantly enhance particle dispersion, a factor that is absent during idling (Jiang et al 2005;Liu et al 2011). In recent years, some researchers have focused on the dispersion of vehicle exhaust pollutants during idling (Ketzel and Berkowicz 2004;Ning et al 2005;Kinsey et al 2007;McNabola et al 2009;Chan et al 2010). The results show that exhaust pollution concentrations, including gaseous pollutants and particles near the tailpipe, decreased rapidly in the first 2 m from the exhaust; similar conclusions were not drawn under moving vehicle conditions.…”

Section: Introductionmentioning

confidence: 90%

“…The results show that exhaust pollution concentrations, including gaseous pollutants and particles near the tailpipe, decreased rapidly in the first 2 m from the exhaust; similar conclusions were not drawn under moving vehicle conditions. Most studies were conducted in open spaces such as an onthe-road environment (Canagaratna et al 2004;Ning et al 2005;Ristovski et al 2005;Kinsey et al 2007;McNabola et al 2009). Few researches have focused on particle variation under idling conditions in an enclosed environment, which is the reality of an underground parking lot (Obaidullah et al 2012;Li et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of particle coagulation in an underground parking lot

Zhao

Kato

Zhao

2015

Environ Sci Pollut Res

View full text Add to dashboard Cite

Particles in vehicle exhaust plumes in underground parking lots have adverse health effects due to the enclosed environment in which they are released and the temperature difference between the tailpipe and ambient environment; at the same time, particle coagulation might be obvious near the tailpipe in an underground parking lot. In the present study, airflow and temperature fields were calculated using the Realizable k-ε model, and the Eulerian particle transport model was selected in the numerical simulation of particle concentration dispersion. Polydisperse thermal coagulation due to Brownian collisions was employed to calculate the particle coagulation. The results show that particle coagulation rate and half-time were significant within 1 m from the tailpipe. The variations in the particle coagulation rate and half-time were similar, but their directions were opposite. Air exhaust time was nearly four times longer than averaged half-time and 40 times longer than minimum half-time. The peak particle diameter increased approximately 1.43 times due to coagulation. A double particle concentration at the tailpipe caused the fourfold rise in the particle coagulation rate in the distance ranging less than 1 m from the tailpipe. An increase in exhaust velocity at the tailpipe could shorten the obvious range of particle coagulation along the centerline of the tailpipe from 1 to 0.8 m in the study.

show abstract

“…Idle exhaust hydrocarbon emissions contain noncombusted fuel compounds and the volatile organics dominate the particle mass emissions. Soot mass emissions, on the other hand, are often considerably lower at idle than at operating loads (Kinsey et al, 2007;Lindgren et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Heavy-duty, off-road diesel engine low-load particle number emissions and particle control

Lähde

Virtanen

Happonen

et al. 2014

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

Exhaust gas particle and ion size distributions were measured from an off-road diesel engine complying with the European Stage IIIB emission standard. The measurements were performed at idling and low load conditions on an engine dynamometer. Nucleation-mode particles dominated the diesel exhaust particle number emissions at idle load. The nonvolatile nucleation-mode geometric mean diameter was detected at 10 nm or below. The nonvolatile nucleation-mode charge state implied that it has evolved through a highly ionizing environment before emission from the engine. The determined charging probabilities were 10.0 AE 2.2% for negative and 8.0 AE 2.0% for positive polarity particles. The nonvolatile nucleation particle concentration and size was also shown to be dependent on the lubricant oil composition. The particle emissions were efficiently controlled with a partial filter or with partial filter þ selective catalytic reduction (SCR) combination. The particle number removal efficiencies of the aftertreatment systems were over 95% for wet total particle number (>3nm) and over 85% for dry particle total number. Nevertheless, the aftertreatment systems' efficiencies were around 50% for the soot-mode particles. The low-load nonvolatile nucleation particle emissions were also dependent on the engine load, speed, and fuel injection pressure. The low load particle number emissions followed the soot-core trade-off, similar to medium or high operating loads.Implications: Idling and low-load diesel engine exhaust emissions affect harmfully the ambient air quality. The low-load particle number emissions are here shown to peak in the 10-nm size range for a modern off-road engine. The particles are electrically charged and nonvolatile and they originate from the combustion process. Tailpipe particle control by open channel filter can remove more than 85% of the nonvolatile 10-nm particles and about 50% of the soot-mode particles, while the fuel injection pressure increase can lead to particle number increase. The study provides a new viewpoint for low-load particle emissions and control.

show abstract

Characterization of Fine Particle and Gaseous Emissions during School Bus Idling

Cited by 20 publications

References 15 publications

Temporal Variations in Airborne Particulate Matter Levels at an Indoor Bus Terminal and Exposure Implications for Terminal Workers

Temporal Variations in Airborne Particulate Matter Levels at an Indoor Bus Terminal and Exposure Implications for Terminal Workers

Characteristics of particle coagulation in an underground parking lot

Heavy-duty, off-road diesel engine low-load particle number emissions and particle control

Contact Info

Product

Resources

About