Title: | Ethylene glycol emissions from on-road vehicles |
Author(s): | Wood EC; Knighton WB; Fortner EC; Herndon SC; Onasch TB; Franklin JP; Worsnop DR; Dallmann TR; Gentner DR; Goldstein AH; Harley RA; |
Address: | "daggerDepartment of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States. double daggerDepartment of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States. section signAerodyne Research, Inc., Billerica, Massachusetts 01821, United States" |
ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
Abstract: | "Ethylene glycol (HOCH2CH2OH), used as engine coolant for most on-road vehicles, is an intermediate volatility organic compound (IVOC) with a high Henry's law coefficient. We present measurements of ethylene glycol (EG) vapor in the Caldecott Tunnel near San Francisco, using a proton transfer reaction mass spectrometer (PTR-MS). Ethylene glycol was detected at mass-to-charge ratio 45, usually interpreted as solely coming from acetaldehyde. EG concentrations in bore 1 of the Caldecott Tunnel, which has a 4% uphill grade, were characterized by infrequent (approximately once per day) events with concentrations exceeding 10 times the average concentration, likely from vehicles with malfunctioning engine coolant systems. Limited measurements in tunnels near Houston and Boston are not conclusive regarding the presence of EG in sampled air. Previous PTR-MS measurements in urban areas may have overestimated acetaldehyde concentrations at times due to this interference by ethylene glycol. Estimates of EG emission rates from the Caldecott Tunnel data are unrealistically high, suggesting that the Caldecott data are not representative of emissions on a national or global scale. EG emissions are potentially important because they can lead to the formation of secondary organic aerosol following oxidation in the atmospheric aqueous phase" |
Keywords: | Aerosols/analysis Air Pollutants/*analysis Boston Environmental Monitoring/*methods Ethylene Glycol/*analysis *Motor Vehicles San Francisco Texas Vehicle Emissions/*analysis Volatile Organic Compounds/analysis; |
Notes: | "MedlineWood, Ezra C Knighton, W Berk Fortner, Ed C Herndon, Scott C Onasch, Timothy B Franklin, Jonathan P Worsnop, Douglas R Dallmann, Timothy R Gentner, Drew R Goldstein, Allen H Harley, Robert A eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2015/02/24 Environ Sci Technol. 2015 Mar 17; 49(6):3322-9. doi: 10.1021/acs.est.5b00557. Epub 2015 Mar 9" |