Assessment of Exposures to Mobile Source Air Toxics

1. 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

2. 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

3. 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

4. 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 California’s 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.54:1138-1150. 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.57:705-720. 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.57:721-740. 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

5. 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

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

7. 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

8. 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

9. 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

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

11. 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

12. 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

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

14. 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

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

16. 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

17. Tunnel Inlet Tunnel outlet Regional Background 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

18. 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

19. 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

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

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

22. Distributions of BTEX Exposures in Atlanta MEs 132 65 583 304 25 2454 58 80 98 465 40 533 Max 3rd Qtr Ave Med 1st Qtr Min API Section 211(B) Tier 2 Exposure Study June 12, 2007 Desert Research Institute

23. 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

24. 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 (<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). June 12, 2007 Desert Research Institute