Sources and concentration of nanoparticles (&lt;10nm diameter) in the urban atmosphere

Shi, Ji Ping; Evans, Douglas E.; Khan, Aftab Aslam Parwaz; Harrison, Roy M.

doi:10.1016/s1352-2310(00)00418-0

Cited by 259 publications

(169 citation statements)

References 25 publications

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“…This method was employed to measure nanoparticle pollution in major cities in Europe, North America, and in Asia. Among other observations in recent citations are the prominence of the nanoparticles, <10 nm, representing about one third of the curbside particle number concentration in UK urban atmospheres (Shi et al 2001). Bimodal PSDs were noted to decay with downwind distance apparently caused by coagulation and atmospheric dilution in several studies (Zhu et al 2002a(Zhu et al , 2002b.…”

Section: Fine Particle Roadway Emissionsmentioning

confidence: 89%

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Dobbins

2007

Aerosol Science and Technology

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The formation of nanoparticles in laboratory hydrocarbon flames is reviewed in terms of particle morphology, chemical composition, and health hazards. The nascent nanoparticles in the nucleation mode have been widely reported in diverse laboratory flames, and are distinguished by their occurrence as singlet particles that form translucent images in transmission electron microscopy (TEM). Their sizes range from about 10 nm or more down to 2 to 3 nm, the limit of resolution of the TEM, and they possess a liquid-like quality. These particles are widely considered to be the precursor stage to the more readily observed carbonaceous aggregates consisting of chained primary particles that are opaque to the electron beam of the TEM. Nanoparticles sampled from the inverse diffusion flame and the particle effluent from diesel engines show a strong resemblance by GCMS analysis, and they contain many of the stabilomer PAHs and their isomers in the 200 to 302 atomic mass range. Many of these chemical species have high relative mutagenicities. Distinctive bimodal particle size distributions can be observed in both flame and engine samples. Recent TEM micrographs of diesel particulates show images of precursor-like nanoparticles, of as yet unknown chemical composition, that are formed in a diesel engine at many operating conditions.

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Section: Fine Particle Roadway Emissionsmentioning

confidence: 89%

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Dobbins

2007

Aerosol Science and Technology

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“…Shi et al 66 measured UFPM concentrations near a roadway and near a stationary source. They concluded that traffic, a stationary combustion source, and secondary aerosol formation all contributed to UFPM concentrations.…”

Section: Evolution Of Ufpm In the Atmospherementioning

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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“…However, a number of recent studies at both rural and urban sites around the world have reported frequent nucleation events (Allen et al 1999;Harrison et al 1999a, b;Harrison et al 2001;Shi et al 2001;Woo et al 2001). Woo et al (2001) found elevated levels of 3-10 nm particles in Atlanta, with highest frequencies in spring and summer.…”

Section: Introductionmentioning

confidence: 99%

Nucleation Events During the Pittsburgh Air Quality Study: Description and Relation to Key Meteorological, Gas Phase, and Aerosol Parameters Special Issue ofAerosol Science and Technologyon Findings from the Fine Particulate Matter Supersites Program

Stanier

Khlystov

Pandis

2004

Aerosol Science and Technology

276

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During the Pittsburgh Air Quality Study (PAQS) aerosol size distributions between 3 nm and 680 nm were measured between July 2001 and June 2002. These distributions have been analyzed to assess the importance of nucleation as a source of ultrafine particles in Pittsburgh and the surrounding areas. The analysis shows nucleation on 50% of the study days and regional-scale formation of ultrafine particles on 30% of the days. Nucleation occurred during all seasons, but it was most frequent in fall and spring and least frequent in winter. Regional nucleation was most common on sunny days with below average PM 2.5 concentrations. Local nucleation events were usually associated with elevated SO 2 concentrations. The observed nucleation events ranged from weak events with only a slight increase in the particle number to relatively intense events with increases of total particle counts between 50,000 cm −3 up to 150,000 cm −3 . Averaging all days of the study, days with nucleation events had number concentrations peaking at around noon at about 45,000 cm −3 . This is compared to work days without nucleation, when the daily maximum was 8 am at 23,000 cm −3 , and to weekends without nucleation, when the daily maximum was at noon at 16,000 cm −3 . Twenty-four-hour average number concentrations were approximately 40% higher on days with nucleation compared to those without. Nucleation was typically observed starting around 9 am EST, although the start of nucleation events was later in winter and earlier in summer. The nucleation events are fairly well correlated with the product of [UV intensity * SO 2 concentration] and also depend on the effective area available for condensation.

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Sources and concentration of nanoparticles (<10nm diameter) in the urban atmosphere

Cited by 259 publications

References 25 publications

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Current Understanding of Ultrafine Particulate Matter Emitted from Mobile Sources

Nucleation Events During the Pittsburgh Air Quality Study: Description and Relation to Key Meteorological, Gas Phase, and Aerosol Parameters Special Issue ofAerosol Science and Technologyon Findings from the Fine Particulate Matter Supersites Program

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