Evolution of particle number distribution near roadways. Part III: Traffic analysis and on-road size resolved particulate emission factors

Zhang, K. Max; Wexler, Anthony S.; Niemeier, Deb; Zhu, Yi; Hinds, William C.; Sioutas, Constantinos

doi:10.1016/j.atmosenv.2005.04.003

Cited by 87 publications

(71 citation statements)

References 32 publications

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“…In order to obtain the size distribution a combination of an electrostatic classifier and a CPC is used. The function of the electrostatic classifier is to separate particles on the basis of their electrical mobility, which is a function of particle diameter (Zhang et al, 2005). This gives an accurate and effective method for size determination of sub-micrometre particles.…”

Section: Particle Countersmentioning

confidence: 99%

“…Several articles and textbooks discuss different aspects of the relations between meteorology and air pollution (see, e.g., Finlayson-Pitts and Pitts, 2000; Seinfeld and Pandis, 1998;Stull, 1995;Zhang et al, 2005). Common parameters such as temperature, wind speed and direction, solar radiation, air pressure, relative humidity and rain, but also, boundary level height and temperature inversions can have an effect on the composition of air.…”

Section: Meteorologymentioning

confidence: 99%

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Personal exposures and indoor, residential outdoor, and urban background levels of fine particle trace elements in the general population

et al. 2006

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The general population is exposed to particulate air pollution from many different local and regional sources. Examples of local sources are traffic, biomass burning and resuspended dust, while regional sources are dominated by combustion processes from heating, traffic and industries. The overall aim of this thesis was to characterise the personal exposure to trace elements in fine particles, mainly PM 2.5 and investigate how the exposure is related to indoor and outdoor levels. Particulate matter was collected on filters and analysed for elemental content by X-ray fluorescence (XRF) spectroscopy.In the general population in Göteborg, personal exposures to Cl, Ca, Ti and Fe were significantly higher compared with indoor, residential outdoor and urban background levels. Significant correlations were also found between urban background PM mass and personal exposure to elements related to both combustion (S, V and Pb) and resuspended dust (Ti, Fe and Zn), indicating that both sources could be relevant for health effects from urban background PM. In a community where wood burning for domestic heating is common, significantly (66-80%) higher personal exposures and indoor levels were found for K, Ca and Zn compared with a reference group living in the same area, indicating that these elements could be good markers for wood smoke. In a study in Stockholm concerning children's environments (home, school and preschool), higher indoor than outdoor levels of Ti were found, while long-range-transported (LRT) elements (S, Ni, Br and Pb) were higher outdoors. A community located 25 km from the city centre had significantly lower outdoor levels of crustal and traffic-related elements compared with both the city centre and a suburban area. The levels of Fe and Cu were four times higher in the central communities. Outdoors, Cu levels were found to correlate well with the traffic marker NO 2 , making it a possible elemental marker for traffic-related aerosols in health studies. Roadside measurements of fine and ultrafine (<100 nm) particles were performed along a major approach road to Göteborg and the levels of ultrafine particles were influenced not only by traffic intensity, but also, by wind speed and direction, as well as boundary layer height. No correlation was found between PM 2.5 and ultrafine particles or traffic, but there was a correlation between PM 2.5 and particles sized 100-368 nm. In all environments studied, the origin of LRT air masses had a strong effect on exposure and levels of PM elements.In conclusion, this thesis demonstrates that elemental analysis is a useful method for better characterising human exposure to fine particles. For several elements, the personal exposure is often higher than corresponding indoor levels. The origin of LRT elements affected not only outdoor levels, but also, the personal exposure and indoor levels, and should be taken into account in time series studies of air pollution and health.

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Section: Particle Countersmentioning

confidence: 99%

Section: Meteorologymentioning

confidence: 99%

Personal exposures and indoor, residential outdoor, and urban background levels of fine particle trace elements in the general population

et al. 2006

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“…This result is not surprising in areas where heavy traffic is widespread, as particles may undergo condensation, agglomeration, evaporation and dilution processes, and, consequently, they may change modal characteristics in time and space. Such atmospheric processes are the main mechanisms reshaping PNSDs after primary exhaust is emitted into the atmosphere, and they have been discussed in several studies (Shi et al, 1999;Kim et al, 2004;Zhang et al, 2005;Zhou et al, 2005;Kulmala and Kerminen, 2008;Zhang et al, 2011;Harrison et al, 2016).…”

Section: Warm Seasonmentioning

confidence: 99%

Sources of sub-micrometre particles near a major international airport

Masiol

Harrison

et al. 2017

Atmos. Chem. Phys.

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Abstract. The international airport of Heathrow is a major source of nitrogen oxides, but its contribution to the levels of sub-micrometre particles is unknown and is the objective of this study. Two sampling campaigns were carried out during warm and cold seasons at a site close to the airfield (1.2 km). Size spectra were largely dominated by ultrafine particles: nucleation particles (< 30 nm) were found to be ∼ 10 times higher than those commonly measured in urban background environments of London. Five clusters and six factors were identified by applying k means cluster analysis and positive matrix factorisation (PMF), respectively, to particle number size distributions; their interpretation was based on their modal structures, wind directionality, diurnal patterns, road and airport traffic volumes, and on the relationship with weather and other air pollutants. Airport emissions, fresh and aged road traffic, urban accumulation mode, and two secondary sources were then identified and apportioned. The fingerprint of Heathrow has a characteristic modal structure peaking at < 20 nm and accounts for 30-35 % of total particles in both the seasons. Other main contributors are fresh (24-36 %) and aged (16-21 %) road traffic emissions and urban accumulation from London (around 10 %). Secondary sources accounted for less than 6 % in number concentrations but for more than 50 % in volume concentration. The analysis of a strong regional nucleation event showed that both the cluster categorisation and PMF contributions were affected during the first 6 h of the event. In 2016, the UK government provisionally approved the construction of a third runway; therefore the direct and indirect impact of Heathrow on local air quality is expected to increase unless mitigation strategies are applied successfully.

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“…Zhang et al 94,95 simulated the evolution of the UFPM size distribution by considering only condensation and evaporation processes with a box model. Although they were able to reproduce observed size distributions, some of their assumptions have been challenged.…”

Section: Modeling Atmospheric Ufpmmentioning

confidence: 99%

Current Understanding of Ultrafine Particulate Matter Emitted from Mobile Sources

Seigneur

2009

Journal of the Air & Waste Management Association

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The physics and chemistry of ultrafine particulate matter (UFPM) associated with mobile source emissions is reviewed. UFPM includes those particles that are less than 0.1 m in diameter. Measurements of UFPM emitted from mobile sources have been conducted in the laboratory, on roadways, and downwind of roadways. In addition, UFPM formation and evolution have been modeled and the modeling results have been compared with available measurements. The results of those measurement programs and modeling studies are synthesized into a coherent description of the formation of UFPM in mobile source emissions and its subsequent evolution in the ambient atmosphere. Recommendations are provided to address the gaps in our current understanding of the processes leading to the formation of UFPM, its chemical composition, and its evolution in the atmosphere.

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Evolution of particle number distribution near roadways. Part III: Traffic analysis and on-road size resolved particulate emission factors

Cited by 87 publications

References 32 publications

Personal exposures and indoor, residential outdoor, and urban background levels of fine particle trace elements in the general population

Personal exposures and indoor, residential outdoor, and urban background levels of fine particle trace elements in the general population

Sources of sub-micrometre particles near a major international airport

Current Understanding of Ultrafine Particulate Matter Emitted from Mobile Sources

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