Title: | "Diurnal and seasonal variability of gasoline-related volatile organic compound emissions in Riverside, California" |
Author(s): | Gentner DR; Harley RA; Miller AM; Goldstein AH; |
Address: | "Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, USA" |
ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
Abstract: | "On- and off-road mobile sources are the dominant contributors to urban anthropogenic volatile organic compound (AVOC) emissions. Analyses of gasoline samples from California for both summer and winter indicate significant differences in liquid fuel and vapor chemical composition due to intentional seasonal adjustments. Ambient concentrations of 55 VOCs were measured via in situ gas chromatography in the 2005 Study of Organic Aerosols at Riverside (SOAR) during both summer and fall. A chemical mass balance analysis was used to differentiate vapor pressure-driven VOC emissions from other motor vehicle-related emissions such as tailpipe exhaust. Overall, fuel vapor emissions accounted for 31 +/- 2% of gasoline-related VOC in Riverside; California's emission factor model similarly estimates 31% of gasoline-related VOC emissions are fuel vapor. The diurnal pattern of vapor pressure-driven VOC source contributions is relatively stable around 10 microg/m3, while whole gasoline (i.e., tailpipe) contributions peak at approximately 60 microg/m3 during the morning commute. There is no peak in whole gasoline source contributions during the afternoon, due to rapid dilution associated with high mixing heights and wind speeds in the Riverside area. The relationship between estimated gasoline-related VOC and observed carbon monoxide concentrations in this study is similar to California's 2005 emission inventory; we calculated a VOC to CO mass ratio of 0.086 +/- 0.006 (95% CI) compared to 0.097 in the emission inventory for all gasoline-related sources" |
Keywords: | Air Pollutants/chemistry Air Pollution California Circadian Rhythm Environmental Monitoring *Gasoline Seasons Vehicle Emissions/*analysis Volatile Organic Compounds/*chemistry; |
Notes: | "MedlineGentner, Drew R Harley, Robert A Miller, Angela M Goldstein, Allen H eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2009/07/17 Environ Sci Technol. 2009 Jun 15; 43(12):4247-52. doi: 10.1021/es9006228" |