Assessment of Exposures to Mobile Source Air Toxics

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Assessment of Exposures to Mobile Source Air
Toxics
Eric M. Fujita Barbara Zielinska Division of
Atmospheric Sciences Desert Research
Institute Reno, NV Air Toxics Workshop
II Houston, Texas June 12-13, 2007
June 12, 2007
Desert Research Institute
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Assessing Exposures to MSATs

• Estimating Exposures to MSAT
• Ambient concentrations at fixed sites versus
  vehicle dominated microenvironments.
• Time spent in various microenvironments by
  population groups.
• Ambient versus personal breathing zone
  concentrations.
• Variations in pollutant concentrations and
  composition in mobile source dominated locations.
• Spatial variations due to proximity.
• Temporal variations (diurnal, daily, day-of-week,
  and seasonal).
• Traffic mix (diesel vs. gasoline, gross polluters
  vs. normal emitters, vehicle operating mode).
• Atmospheric transformation (chemical and
  physical).

June 12, 2007
Desert Research Institute
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Acknowledgments

• Comparative Toxicity Study
• Sponsor DOEs Office of FreedomCAR and Vehicle
  Technologies
• Weekend Ozone Study
• Sponsor DOEs Office of FreedomCAR and Vehicle
  Technologies Coordinating Research Council
• Additional Support South Coast Air Quality
  Management District
• Gasoline/Diesel PM Split Study
• Sponsor DOEs Office of FreedomCAR and Vehicle
  Technologies
• Additional Support U.S. Environmental Protection
  Agency. California Bureau of Automotive Repair,
  South Coast Air Quality Management District,
  Ralphs Supermarket Distribution Center
• Kansas City Vehicle Characterization Study
• Sponsor U.S. Environmental Protection Agency
  Office of Transportation and Air Quality
• Additional Support DOEs Office of FreedomCAR
  and Vehicle Technologies, Coordinating Research
  Council, U.S. Federal Highway Administration.
• Section 211(B) Tier 2 High End Exposures
• Sponsor American Petroleum Institute
• Additional Input U.S. Environmental Protection
  Agency
• Assessing Exposure to Air Toxics in
  Microenvironments Dominated by Mobile Sources
• Sponsor Health Effects Institute
• Additional Support South Coast Air Quality
  Management District.
• Atmospheric Transformations of Diesel Exhaust
• Sponsor Health Effects Institute

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References
Fujita, E.M., D.E. Campbell, B. Zielinska, J.C.
Sagebiel, J.L. Bowen, W. Goliff, W.R. Stockwell,
and D.R. Lawson (2003). Diurnal and Weekday
Variations in Source Contributions of Ozone
Precursors in Californias South Coast Air Basin.
J. Air Waste Manage. Assoc. 53
844-863. Zielinska, B., W.S. Goliff, M. McDaniel,
T. Cahill, D. Kittleson and W. Watts (2003).
Chemical Analyses of Collected Diesel Particulate
Matter Samples in the CRC E-43 Project. Prepared
for the National Renewable Energy Laboratory,
Golden, CO. Zielinska, B. J. Sagebiel, J.D.
McDonald, K. Whitney and D.R. Lawson (2004).
Emission Rates and Comparative Chemical
Composition from Selected In-Use Diesel and
Gasoline-Fueled Vehicles. J. Air Waste Manage.
Assoc. 541138-1150. Fujita, E.M. and D.E.
Campbell (2006). Spatial and Temporal Variations
in Exposure to Air Toxics in the South Coast Air
Basin. Final report submitted by Desert Research
Institute to the National Renewable Energy
Laboratory, Golden, CO, August 31, 2006. Fujita,
E.M., D.E. Campbell, B. Zielinska, W.P. Arnott
and J.C. Chow (2007). Exposure to Air Toxics in
Mobile Source Dominated Microenvironments. Draft
report submitted by Desert Research Institute to
the Health Effects Institute, Boston, MA,
February 6, 2007. Fujita, E.M., B. Zielinska,
D.E. Campbell, W.P. Arnott, J. Sagebiel, L.
Reinhart, J.C. Chow, N. P.A. Gabele, W. Crews, R.
Snow, N. Clark, S. Wayne and D.R. Lawson (2007).
Variations in speciated emissions from
spark-ignition and compression ignition motor
vehicles in the California's South Coast Air
Basin. J. Air Waste Manage. Assoc.
57705-720. Fujita, E. M., D. E. Campbell, W. P.
Arnott, B. Zielinska (2007). Evaluations Of
Source Apportionment Methods for Determining
Contributions Of Gasoline and Diesel Exhaust to
Ambient Carbonaceous Aerosols. J. Air Waste
Manage. Assoc. 57721-740. Zielinska, B., J.
Sagebiel, S. Samy, JC. Seagrave, J. McDonald, P.
Wiesen and K. Wirtz (2007) Atmospheric
Transformation of Diesel Emissions, Poster
presented at 2006 HEI Annual Conference, Chicago,
Il, April 15-17, 2006.
June 12, 2007
Desert Research Institute
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Average Hourly Light-Duty and Heavy-Duty Traffic
Volumes Weigh-in-Motion Sites in Interior of
South Coast Air Basin
Light-Duty
Heavy-Duty
DOE NREL Weekend Ozone Study Courtesy of Sonoma
Technology, Inc., 2002
June 12, 2007
Desert Research Institute
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Photoacoustic Black Carbon (1-minute averages)
Sunday
Weekday
Gasoline/Diesel PM Split Study
June 12, 2007
Desert Research Institute
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Weekday Variations in CO and Black Carbon at
Azusa9/30/00 to 10/8/00 - Weekend Ozone Study
Weekend Ozone Study
June 12, 2007
Desert Research Institute
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Weekday Variations in BC NOx versus CO NMHC
at Azusa9/30/00 to 10/8/00 - Weekend Ozone Study
CO and NMHC
BC and NOx
Weekend Ozone Study
June 12, 2007
Desert Research Institute
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CMB Source Contribution Estimates for Total
Carbonat Azusa, Los Angeles and Other Sites
Mainly diesel at Azusa and LA, but mixed at other
sites Large residual fraction.
Gasoline/Diesel PM Split Study
June 12, 2007
Desert Research Institute
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CMB Source Contribution Estimates for Benzene
Toluene
Weekend Ozone Study
June 12, 2007
Desert Research Institute
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DustTrak PM mass (ug/m3) for Phase 2 of the LA92
CycleSummer Study
Stratum 5 (pre-81) Stratum 6 (1981-90)
Stratum 7 (1991-95) Stratum 8 (1996)
Kansas City Vehicle Emissions Characterization
Study
June 12, 2007
Desert Research Institute
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Ascending PM2.5 Emission Rates within Model Year
GroupsKansas City Vehicle Emissions
Characterization Study
High emitters contributed a disproportionate
share of the PM emissions (17 in Round 1 and 24
in Round 2 contribute 75 of the total).
Source EPA OTAQ
June 12, 2007
Desert Research Institute
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Kansas City Vehicle Characterization Study-
Summer Volatile, Semi-Volatile and Particulate
PAHs
Kansas City Vehicle Characterization Study
June 12, 2007
Desert Research Institute
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Comparative Emissions and Toxicity of Gasoline
and Diesel Vehicles
F Filter P PUF/XAD
Gasoline Vehicles G Average Gasoline at 72
F BG Black Smoker at 72 F WG White Smoker at
72 F G30 G at 30 F NG New Technology
Diesel Vehicles D Average Diesel at 72
F HD High PM Emitter at 72 F D30 D at 30 F
June 12, 2007
Desert Research Institute
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Chamber Reaction of Toluene with Diesel
ExhaustOpen Path FTIR Data
HEI Study Atmospheric Transformations of Diesel
Exhaust
June 12, 2007
Desert Research Institute
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Time Evolution of Diesel Exhaust Particle Size
Distributions with Photochemical Reactions of
Toluene

• Addition of 500 ppb of toluene (NOx 100 ppb)
  resulted in a substantial secondary aerosol
  formation.
• Initial DPM concentration 9 µg/m3
• peak PM concentration 57 µg/m3

HEI Study Atmospheric Transformations of Diesel
Exhaust
June 12, 2007
Desert Research Institute
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Particle Number Concentration Distribution at the
Tuscarora Tunnel, 5/21/99
Source HEI Project 98-3 courtesy of Dr. Fred
Rogers, Desert Research Institute.
June 12, 2007
Desert Research Institute
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Concentration Distributions on nano-MOUDI
Stagesof Organic Compounds in Diesel Exhaust
(Light Cruise)
Source Zielinska et al. 2003, Project Report for
CRC-E43.
June 12, 2007
Desert Research Institute
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Black Carbon (1-minute) by Photoacoustic
Diamond Bar
60
Lynwood
710
605
405
110
91
Long Beach
Health Effects Institute Project RFA03-1
June 12, 2007
Desert Research Institute
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Comparisons of On-Road Versus Fixed
StationSummer Morning CO
Health Effects Institute Project RFA03-1
June 12, 2007
Desert Research Institute
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Comparisons of On-Road Versus Fixed
StationSummer Morning NOx
Health Effects Institute Project RFA03-1
June 12, 2007
Desert Research Institute
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Distributions of BTEX Exposures in Atlanta MEs
132
65
583
304
25
2454
58
80
465
98
40
533
Max
3rd Qtr
Ave
Med
1st Qtr
Min
API Section 211(B) Tier 2 Exposure Study
June 12, 2007
Desert Research Institute
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Mean ME to Air Monitoring Station Ratiosof MSAT
for Corresponding Hours - Houston
Log Scale
API Section 211(B) Tier 2 Exposure Study
June 12, 2007
Desert Research Institute
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Summary and Conclusions

• Ambient levels of volatile organic MSATs in the
  SoCAB were mainly associated with gasoline
  vehicles.
• On-road CO, NMHC, and volatile MSATs were 2-5
  times higher than fixed monitoring sites (1-hour
  averages).
• Diesel vehicles were the dominant mobile source
  of EC and TC at two fixed monitoring sites (Azusa
  and Los Angeles).
• However source contributions of gasoline and
  diesel vehicles varied with location and time.
• On-road NO and BC were about an order of
  magnitude higher than at fixed monitoring sites
  (1-hour averages).
• Short-term on-road exposures (few minute or less)
  can be substantially higher (10 to 100 times
  higher) and depend on proximity of high gasoline
  emitters and diesel trucks.
• Over half of the organic carbon during summer in
  the SoCAB could not be apportioned to
  directly-emitted PM emissions from motor
  vehicles.
• Gasoline vehicles are predominant source of
  anthropogenic SOA precursors (volatile and
  semi-volatile aromatic hydrocarbons.
• Concentrations of ultrafine particles (lt0.1 ?m)
  are greatest in fresh emissions and rapidly grow
  to accumulation size particles (0.1 to 1.0 ?m).
• High emitters contributed a disproportionate
  share of the PM emissions (about 20 of the
  vehicles contributed 75 of the total).

June 12, 2007
Desert Research Institute