DOI: 10.1016/j.atmosenv.2016.10.042
Scopus记录号: 2-s2.0-84995471886
论文题名: Oxidative potential of on-road fine particulate matter (PM2.5) measured on major freeways of Los Angeles, CA, and a 10-year comparison with earlier roadside studies
作者: Shirmohammadi F ; , Wang D ; , Hasheminassab S ; , Verma V ; , Schauer J ; J ; , Shafer M ; M ; , Sioutas C
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 148 起始页码: 102
结束页码: 114
语种: 英语
英文关键词: Dithiothreitol (DTT) assay
; EC and OC
; Metals and elements
; Oxidative potential
; Particulate matter
; Tailpipe and non-tailpipe emissions
Scopus关键词: Aromatic hydrocarbons
; Diesel locomotives
; Iodine
; Lead
; Manganese
; Organic carbon
; Particles (particulate matter)
; Roads and streets
; Roadsides
; Trace elements
; Transportation
; Urban growth
; Dithiothreitol
; EC and OC
; Oxidative potential
; Particulate Matter
; Tailpipe emission
; Polycyclic aromatic hydrocarbons
; aluminum
; antimony
; barium
; benzo[a]pyrene
; benzo[e]pyrene
; benzo[ghi]perylene
; calcium
; carbon
; chromium
; chrysene
; copper
; dithiothreitol
; fluoranthene
; indeno[1,2,3 cd]pyrene
; iron
; lead
; magnesium
; manganese
; metal
; nickel
; organic carbon
; phenanthrene
; polycyclic aromatic hydrocarbon
; potassium
; sodium
; sulfur
; titanium
; trace element
; vanadium
; zinc
; chemical composition
; comparative study
; concentration (composition)
; diesel engine
; elemental carbon
; emission control
; exhaust emission
; motorway
; organic carbon
; oxidation
; PAH
; particle size
; particulate matter
; pollution monitoring
; road
; roadside environment
; sulfide
; Article
; California
; combustion
; controlled study
; correlational study
; highway
; measurement
; molecular weight
; oxidation reduction potential
; particulate matter
; priority journal
; reduction
; surface property
; California
; Los Angeles Basin
; Los Angeles [California]
; United States
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: This study describes on-road measurements of fine particulate matter (PM2.5) using a mobile instrumentation platform to assess the chemical composition and oxidative potential of PM2.5, using the dithiothreitol (DTT) assay, over three representative roadways in the Los Angeles Basin: the I-110 and I-710 freeways, the Wilshire/Sunset boulevards as well as the main campus of the University of Southern California (USC), used as a reference urban background site. Samples were chemically analyzed for elemental carbon (EC), organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs) and 50 elements. The cumulative mass fraction of the measured PAHs was highest on the freeways (0.16 ± 0.01 and 0.15 ± 0.01 ng/μg PM, on I-110 and I-710, respectively); which on average was 3 and 3.3-fold higher than at Wilshire/Sunset and USC site, respectively. Mass fractions of Ba, Cr, Cu, Mn, Ni, Pb, Sb and Zn, tracers of vehicular abrasion, were 3.8 ± 0.8 times higher on both freeways in comparison to Wilshire/Sunset. The observed intrinsic (normalized per PM mass) DTT activity was greatest on freeways, averaging 30.13 ± 3.15 nmol/min mg PM and being roughly 1.9 and 2.1 times higher than the values obtained at Wilshire/Sunset and USC, respectively. Furthermore, comparison of our results with previous on-road and roadside studies conducted in the last decade in Los Angeles indicated an overall reduction in the contribution of carbonaceous species and PAHs (important tracers of exhaust emissions) to PM mass, especially on I-710 freeway with the higher heavy-duty diesel vehicle fraction, indicating the effectiveness of diesel vehicle emissions control policies implemented in recent years in California. In contrast, greater contributions of certain groups of metals and trace elements that are indicators of non-tailpipe emissions compared to previous studies provide evidence on the increasing importance of non-tailpipe emissions to the oxidative potential of on-road PM2.5 as vehicular exhaust emissions becomes cleaner. This finding was also reflected in the increased levels of on-road DTT activity by factors of 1.4–1.5 in comparison to the DTT activity of vehicular emissions estimated in previous dynamometer studies. © 2016 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/82454
Appears in Collections: 气候变化事实与影响
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作者单位: University of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, United States; University of Illinois at Urbana-Champaign, Department of Civil and Environmental Engineering, Urbana-Champaign, IL, United States; University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, WI, United States
Recommended Citation:
Shirmohammadi F,, Wang D,, Hasheminassab S,et al. Oxidative potential of on-road fine particulate matter (PM2.5) measured on major freeways of Los Angeles, CA, and a 10-year comparison with earlier roadside studies[J]. Atmospheric Environment,2017-01-01,148