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 Desert Research Institute June 12, 2007

 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). Assessing Exposures to MSATs Desert Research Institute June 12, 2007

Acknowledgments Comparative Toxicity Study – Sponsor: DOE’s Office of FreedomCAR and Vehicle Technologies Weekend Ozone Study – Sponsor: DOE’s Office of FreedomCAR and Vehicle Technologies; Coordinating Research Council – Additional Support: South Coast Air Quality Management District Gasoline/Diesel PM Split Study – Sponsor: DOE’s Office of FreedomCAR and Vehicle Technologies – Additional Support: U.S. Environmental Protection Agency. California Bureau of Automotive Repair, South Coast Air Quality Management District, Ralph’s Supermarket Distribution Center Kansas City Vehicle Characterization Study – Sponsor: U.S. Environmental Protection Agency Office of Transportation and Air Quality – Additional Support: DOE’s 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

References Desert Research Institute June 12, 2007 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 California’s South Coast Air Basin. J. Air & Waste Manage. Assoc. 53: 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. 54: 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, 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, 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. 57: 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. 57: 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.

Average Hourly Light-Duty and Heavy-Duty Traffic Volumes Weigh-in-Motion Sites in Interior of South Coast Air Basin Desert Research Institute June 12, 2007 DOE NREL Weekend Ozone Study Courtesy of Sonoma Technology, Inc., 2002 Heavy-Duty Light-Duty

Photoacoustic Black Carbon (1-minute averages) Desert Research Institute June 12, 2007 Gasoline/Diesel PM Split Study Sunday Weekday

Weekday Variations in CO and Black Carbon at Azusa 9/30/00 to 10/8/00 - Weekend Ozone Study Desert Research Institute June 12, 2007 Weekend Ozone Study

Desert Research Institute June 12, 2007 Weekday Variations in BC & NOx versus CO & NMHC at Azusa 9/30/00 to 10/8/00 - Weekend Ozone Study BC and NOx CO and NMHC Weekend Ozone Study

CMB Source Contribution Estimates for Total Carbon at Azusa, Los Angeles and Other Sites Desert Research Institute June 12, 2007 Gasoline/Diesel PM Split Study Mainly diesel at Azusa and LA, but mixed at other sites Large residual fraction.

Desert Research Institute June 12, 2007 CMB Source Contribution Estimates for Benzene & Toluene Weekend Ozone Study

DustTrak PM mass (ug/m3) for Phase 2 of the LA92 Cycle Summer Study Stratum 5 (pre-81) Stratum 6 ( ) Stratum 7 ( ) Stratum 8 (1996+) Kansas City Vehicle Emissions Characterization Study Desert Research Institute June 12, 2007

Ascending PM 2.5 Emission Rates within Model Year Groups Kansas 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 Desert Research Institute June 12, 2007

Kansas City Vehicle Characterization Study- Summer Volatile, Semi-Volatile and Particulate PAHs Desert Research Institute June 12, 2007 Kansas City Vehicle Characterization Study

Comparative Emissions and Toxicity of Gasoline and Diesel Vehicles Desert Research Institute June 12, 2007 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 F = Filter P = PUF/XAD

Chamber Reaction of Toluene with Diesel Exhaust Open Path FTIR Data Desert Research Institute June 12, 2007 HEI Study – Atmospheric Transformations of Diesel Exhaust

Time Evolution of Diesel Exhaust Particle Size Distributions with Photochemical Reactions of Toluene Desert Research Institute June 12, 2007 Addition of ~500 ppb of toluene (NOx ~100 ppb) resulted in a substantial secondary aerosol formation. Initial DPM concentration: 9 µg/m 3 peak PM concentration: 57 µg/m 3 HEI Study – Atmospheric Transformations of Diesel Exhaust

Particle Number Concentration Distribution at the Tuscarora Tunnel, 5/21/99 Desert Research Institute June 12, 2007 Tunnel Inlet Tunnel outlet Regional Background * Source: HEI Project 98-3 courtesy of Dr. Fred Rogers, Desert Research Institute.

Concentration Distributions on nano-MOUDI Stages of Organic Compounds in Diesel Exhaust (Light Cruise) Desert Research Institute June 12, 2007 Source: Zielinska et al. 2003, Project Report for CRC-E43.

Desert Research Institute June 12, 2007 Health Effects Institute Project RFA03-1 Black Carbon (1-minute) by Photoacoustic Long Beach Diamond Bar Lynwood

Comparisons of On-Road Versus Fixed Station Summer Morning CO Desert Research Institute June 12, 2007 Health Effects Institute Project RFA03-1

Comparisons of On-Road Versus Fixed Station Summer Morning NOx Desert Research Institute June 12, 2007 Health Effects Institute Project RFA03-1

Distributions of BTEX Exposures in Atlanta MEs Desert Research Institute June 12, st Qtr Max Min 3 rd Qtr Med Ave API Section 211(B) Tier 2 Exposure Study

Mean ME to Air Monitoring Station Ratios of MSAT for Corresponding Hours - Houston Desert Research Institute June 12, 2007 Log Scale API Section 211(B) Tier 2 Exposure Study

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 (<0.1  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). Summary and Conclusions Desert Research Institute June 12, 2007