PM2.5 chemical source profiles for vehicle exhaust, vegetative burning, geological material, and coal burning in Northwestern Colorado during 1995

Abstract. Fine particles (PM2.5, i.e., particles with an aerodynamic diameter of ≤2.5 μm) were collected from the air in August 2005, August–September 2006, and January–February 2007, in Beijing, China. The chemical compositions of particulate organic matter in the ambient samples were quantified by gas chromatography/mass spectrometry. The dominant compounds identified in summertime were n-alkanoic acids, followed by dicarboxylic acids and sugars, while sugars became the most abundant species in winter, followed by polycyclic aromatic hydrocarbons, n-alkanes, and n-alkanoic acids. The contributions of seven emission sources (i.e., gasoline/diesel vehicles, coal burning, wood/straw burning, cooking, and vegetative detritus) to particulate organic matter in PM2.5 were estimated using a chemical mass balance receptor model. The model results present the seasonal trends of source contributions to organic aerosols. Biomass burning (straw and wood) had the highest contribution in winter, followed by coal burning, vehicle exhaust, and cooking. The contribution of cooking was the highest in summer, followed by vehicle exhaust and biomass burning, while coal smoke showed only a minor contribution to ambient organic carbon.

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Receptor Model Source Apportionment of Nonmethane Hydrocarbons in Mexico City

The Scientific World JOURNAL ◽

10.1100/tsw.2002.147 ◽

2002 ◽

Vol 2 ◽

pp. 844-860 ◽

Cited By ~ 13

Author(s):

V. Mugica ◽

J. Watson ◽

E. Vega ◽

E. Reyes ◽

M.E. Ruiz ◽

...

Keyword(s):

Mexico City ◽

Motor Vehicle ◽

Ambient Air ◽

Nonmethane Hydrocarbons ◽

Receptor Model ◽

Liquefied Petroleum Gas ◽

Vehicle Exhaust ◽

Source Profiles ◽

Source Contributions ◽

Initial Source

With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC) to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas), asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

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Aromatic Hydrocarbons in Urban and Suburban Atmospheres in Central China: Spatiotemporal Patterns, Source Implications, and Health Risk Assessment

Atmosphere ◽

10.3390/atmos10100565 ◽

2019 ◽

Vol 10 (10) ◽

pp. 565 ◽

Cited By ~ 2

Author(s):

Zeng ◽

Guo ◽

Cheng ◽

Wang ◽

Zeng ◽

...

Keyword(s):

Risk Assessment ◽

Health Risk ◽

Health Risk Assessment ◽

Aromatic Hydrocarbons ◽

Local Governments ◽

Central China ◽

Urban Site ◽

Air Pollution Control ◽

Vehicle Exhaust ◽

Coal Burning

: Ambient aromatic hydrocarbons (AHs) are hazardous air pollutants and the main precursors of ozone (O3). In this study, the characteristics of ambient AHs were investigated at an urban site (Ziyang, ZY) and a suburban site (Jiangxia, JX) in Wuhan, Central China, in 2017. The positive matrix factorization (PMF) model was used to investigate the sources of AHs, and a health risk assessment was applied to estimate the effects of AHs on human health. The concentrations of total AHs at ZY (2048 ± 1364 pptv) were comparable (p > 0.05) to that (2023 ± 1015 pptv) at JX. Source apportionment results revealed that vehicle exhaust was the dominant source of both, total AHs, and toluene, contributing 51.9 ± 13.1% and 49.3 ± 9.5% at ZY, and 44.7 ± 12.6% and 43.2 ± 10.2% at JX, respectively. Benzene was mainly emitted from vehicle exhaust at ZY (50.2 ± 15.5%), while it was mainly released from biomass and coal burning sources at JX (50.6 ± 16.7%). The health risk assessment results indicated that AHs did not have a significant non-carcinogenic risk, while the carcinogenic risks of benzene exceeded the regulatory limits set by the USEPA for adults (1 × 10−6) at both sites. Hence, controlling the emissions of vehicular and biomass/coal burning sources will be an effective way to reduce ambient AHs and the health risk of benzene exposure in this region. These findings will enhance our knowledge of ambient AHs in Central China and be helpful for local governments to formulate air pollution control strategies.

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Chemical source profiles for particulate motor vehicle exhaust under cold and high altitude operating conditions

The Science of The Total Environment ◽

10.1016/0048-9697(90)90107-6 ◽

1990 ◽

Vol 93 ◽

pp. 183-190 ◽

Cited By ~ 14

Author(s):

J.G. Watson ◽

J.C. Chow ◽

L.C. Pritchett ◽

J.A. Houck ◽

R.A. Ragazzi ◽

...

Keyword(s):

High Altitude ◽

Motor Vehicle ◽

Operating Conditions ◽

Vehicle Exhaust ◽

Source Profiles

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Source apportionment of fine organic aerosols in Beijing

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-9043-2009 ◽

2009 ◽

Vol 9 (2) ◽

pp. 9043-9080 ◽

Cited By ~ 3

Author(s):

Q. Wang ◽

M. Shao ◽

Y. Zhang ◽

Y. Wei ◽

M. Hu ◽

...

Keyword(s):

Organic Matter ◽

Particulate Organic Matter ◽

Biomass Burning ◽

Fine Particles ◽

Organic Aerosols ◽

Abundant Species ◽

Gas Chromatography Mass Spectrometry ◽

Vehicle Exhaust ◽

Coal Burning ◽

Alkanoic Acids

Abstract. Fine particles (PM2.5, i.e., particles with an aerodynamic diameter of ≤2.5 μm) were collected from the air in August 2006, August–September 2006, and January–February 2007, in Beijing, China. Particulate organic matter in the ambient samples was quantified by gas chromatography/mass spectrometry. The dominant compounds identified in summertime were n-alkanoic acids, followed by dicarboxylic acids and sugars, while sugars became the most abundant species in winter, followed by polycyclic aromatic hydrocarbons, n-alkanes, and n-alkanoic acids. The contributions of seven emission sources (i.e., gasoline/diesel vehicles, coal burning, wood/straw burning, cooking, and vegetative detritus) to particulate organic matter in PM2.5 were estimated using a chemical mass balance receptor model. The model runs the present seasonal trends regarding the contributions of various sources to organic aerosols. Biomass burning (straw and wood) had the highest contribution in winter, followed by coal burning, vehicle exhaust, and cooking. The contribution of cooking was the highest in summer, followed by vehicle exhaust and biomass burning, while coal smoke showed only a minor contribution to ambient organic carbon.

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Determination and Similarity Analysis of PM2.5 Emission Source Profiles Based on Organic Markers for Monterrey, Mexico

Atmosphere ◽

10.3390/atmos12050554 ◽

2021 ◽

Vol 12 (5) ◽

pp. 554

Author(s):

Yasmany Mancilla ◽

Gerardo Medina ◽

Lucy T. González ◽

Pierre Herckes ◽

Matthew P. Fraser ◽

...

Keyword(s):

Source Apportionment ◽

Ad Hoc ◽

Pollution Abatement ◽

Chemical Species ◽

Airborne Particulate Matter ◽

Source Attribution ◽

Vehicle Exhaust ◽

Industrial Emissions ◽

Source Profiles ◽

Organic Markers

Source attribution of airborne particulate matter (PM) relies on a host of different chemical species. Organic molecular markers are a set of particularly useful marker compounds for estimating source contributions to the fine PM fraction (i.e., PM2.5). Although there are many source apportionment studies based on organic markers, these studies heavily rely on the few studies that report region-specific emission profiles. Source attribution efforts, particularly those conducted in countries with emerging economies, benefit from ad hoc information to conduct the corresponding analyses. In this study, we report organic molecular marker source profiles for PM2.5 emitted from 12 major sources types from five general source categories (meat cooking operations, vehicle exhausts, industries, biomass and trash burning, and urban background) for the Monterrey Metropolitan Area (Mexico). Source emission samples were obtained from a ground-based source-dominated sampling approach. Filter-based instruments were utilized, and the loaded filters were chemically characterized for organic markers by GC-MS. Levoglucosan and cholesterol dominate charbroiled-cooking operation sources while methoxyphenols, PAHs and hopanes dominate open-waste burning, vehicle exhaust and industrial emissions, respectively. A statistical analysis showed values of the Pearson distance < 0.4 and the similarity identity distance > 0.8 in all cases, indicating dissimilar source profiles. This was supported by the coefficient of divergence average values that ranged from 0.62 to 0.72. These profiles could further be utilized in receptor models to conduct source apportionment in regions with similar characteristics and can also be used to develop air pollution abatement strategies.

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The 'well-known' theory of electron image formation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075233 ◽

1983 ◽

Vol 41 ◽

pp. 288-289

Author(s):

M.A. O'Keefe ◽

W.O. Saxton

Keyword(s):

Image Processing ◽

Image Formation ◽

Source Profiles ◽

Electron Image

A recent paper by Kirkland on nonlinear electron image processing, referring to a relatively new textbook, highlights the persistence in the literature of calculations based on incomplete and/or incorrect models of electron imageing, notwithstanding the various papers which have recently pointed out the correct forms of the appropriate equations. Since at least part of the problem can be traced to underlying assumptions about the illumination coherence conditions, we attempt to clarify both the assumptions and the corresponding equations in this paper, illustrating the effects of an incorrect theory by means of images calculated in different ways.The first point to be made clear concerning the illumination coherence conditions is that (except for very thin specimens) it is insufficient simply to know the source profiles present, i.e. the ranges of different directions and energies (focus levels) present in the source; we must also know in general whether the various illumination components are coherent or incoherent with respect to one another.

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