Thesis
Air toxic emissions from mobile sources in winter
Washington State University
Master of Science (MS), Washington State University
2011
Handle:
https://hdl.handle.net/2376/103241
Abstract
The US Environmental Protection Agency has labeled six air toxics to be the most hazardous to human health, including formaldehyde, acetaldehyde and benzene. In urban areas, these are mainly emitted by vehicles when lower temperature inhibits biogenic emissions. Among these toxics benzene is a well known carcinogen and the aldehydes (formaldehyde and acetaldehyde) can also contribute to ground level ozone formation besides affecting human health. To estimate toxic emissions from mobile sources, toxic assessment programs can use emission ratios along with ambient monitoring data. In this study, emission ratios relative to vehicle exhaust tracers (CO and NOX) were calculated by using parameters from regression analysis. Formaldehyde, acetaldehyde and benzene along with other volatile organic compounds (VOCs) and trace gases (CO, NOX) were measured in winter from December 2008 to January 2009 as a part of the Treasure Valley PM2.5 campaign in Meridian, Idaho. By analyzing the morning rush hour period, we found that the emissions ratios with respect to CO were 3.30 ± 0.29 pptv/ppbv, 2.11 ± 0.20 pptv/ppbv and 1.30 ± 0.07 pptv/ppbv for formaldehyde, acetaldehyde and benzene respectively. The emission ratios with respect to NOX were 11.9 ± 1.2 pptv/ppbv, 7.99 ± 1.03 pptv/ppbv and 5.06 ± 0.47 pptv/ppbv for formaldehyde, acetaldehyde and benzene respectively. These emission ratios with CO were found to be in reasonable agreement with previous studies done in various cities. The measured emission ratios were also compared with calculated ones from modeled data generated by AIRPACT-3. The measured emission ratios, for aldehydes with respect to NOX and for benzene with respect to CO, were comparable to the modeled ones. The good agreement for AIRPACT versus observations, for NOX correlations compared to those with CO, suggests that the CO emission from the model is over predicted by a factor of 5.2.
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Details
- Title
- Air toxic emissions from mobile sources in winter
- Creators
- Farah N. Abedin
- Contributors
- Bertram Thomas Jobson (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525073301842
- Language
- English
- Resource Type
- Thesis