Grantee Research Project Results
2012 Progress Report: Evaluation of Mobile Source Emissions and Trends Using Detailed Chemical and Physical Measurements
EPA Grant Number: R834553Title: Evaluation of Mobile Source Emissions and Trends Using Detailed Chemical and Physical Measurements
Investigators: Harley, Robert A. , Goldstein, Allen H. , Wood, Ezra
Current Investigators: Harley, Robert A. , Goldstein, Allen H.
Institution: University of California - Berkeley , Aerodyne Research Inc.
Current Institution: University of California - Berkeley
EPA Project Officer: Chung, Serena
Project Period: April 1, 2010 through March 31, 2014
Project Period Covered by this Report: April 1, 2012 through March 31,2013
Project Amount: $500,000
RFA: Novel Approaches to Improving Air Pollution Emissions Information (2009) RFA Text | Recipients Lists
Research Category: Particulate Matter , Climate Change , Air
Objective:
The overall objective is to evaluate mobile source emissions and trends over time. Both gasoline and diesel engine emissions were measured, and there was special emphasis on characterizing emission factor distributions for pollutants emitted by heavy-duty diesel trucks. Also, exhaust particulate emissions have been characterized in much greater detail than has been reported previously. This research includes as a major element a 2010 field study to measure current on-road diesel and gasoline vehicle emission rates and exhaust composition profiles, featuring new instrumentation for enhanced characterization of emission factor distributions.
Progress Summary:
During the current reporting period, we completed analyses of our field measurements of motor vehicle emissions at the Caldecott tunnel in the San Francisco Bay area. We assessed the relative importance of gasoline and diesel sources as contributors to various air pollutants. We found the diesel contribution to be dominant for nitrogen oxides (NOx), black carbon (BC), and primary organic aerosol (POA). The diesel contribution was also found to be significant for secondary organic aerosol (SOA), due to emissions of heavy hydrocarbons in diesel exhaust that have high aerosol-forming potential. We used advanced analysis methods to measure the chemical composition of primary organic aerosol emissions, and noted that gasoline and diesel emissions of this pollutant look similar, consistent with a common lubricating oil-related source of emissions for both engine types. We were able to quantify the majority of organic compound mass present in organic aerosol emissions, unlike past studies where only a small fraction (much less than half of the total) of the organics could be resolved and identified.
Future Activities:
Further reporting of project results is planned, both in the form of journal articles and conference presentations.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 19 publications | 9 publications in selected types | All 9 journal articles |
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Dallmann TR, DeMartini SJ, Kirchstetter TW, Herndon SC, Onasch TB, Wood EC, Harley RA. On-road measurement of gas and particle phase pollutant emission factors for individual heavy-duty diesel trucks. Environmental Science & Technology 2012;46(15):8511-8518. |
R834553 (2012) R834553 (Final) |
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Gentner DR, Isaacman G, Worton DR, Chan AW, Dallmann TR, Davis L, Liu S, Day DA, Russell LM, Wilson KR, Weber R, Guha A, Harley RA, Goldstein AH. Elucidating secondary organic aerosol from diesel and gasoline vehicles through detailed characterization of organic carbon emissions. Proceedings of the National Academy of Sciences of the United States of America 2012;109(45):18318-18323. |
R834553 (2012) R834553 (Final) |
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McDonald BC, Dallmann TR, Martin EW, Harley RA. Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales. Journal of Geophysical Research:Atmospheres 2012;117(D21):D00V18 (11 pp.). |
R834553 (2012) R834553 (Final) |
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Supplemental Keywords:
Gasoline, diesel, nitrogen oxides, particulate matter, carbon monoxide, formaldehyde, nitrogen dioxide, organic carbon speciation, black carbon, aerosol mass spectrometerProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.