AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Traffic-Related Pollutant Emission Factors from Near-Road Measurements for Various Vehicle Types in Downtown Toronto
JON M WANG, Cheol-Heon Jeong, Robert Healy, Greg J. Evans, SOCAAR, University of Toronto
Abstract Number: 460 Working Group: Urban Aerosols
Abstract Vehicle emissions contribute significantly to urban air pollution and the resulting exposure has been associated with cancer, cardiovascular, and pulmonary diseases. Models can be used to estimate traffic-related pollution exposure, but this is complicated by changing vehicle emission control technologies, unknown vehicle fleet composition, and uncertainties related to emerging unregulated pollutants. Model accuracy is greatly influenced by how well fleet average emission factors are representative of local vehicle emissions. Up-to-date and accurate emission factors relevant to specific cities would help close the gap between measured and modelled pollutant concentrations.
The goal of this study was to develop a simple method to use near-road measurements to calculate emission factors and use this to determine local emission factors for various vehicle types in downtown Toronto. Continuous stationary pollutant concentrations were measured at high time resolution 15 metres away from a major roadway. Emission factors were calculated using a carbon balance method with selected pollutants normalized to carbon dioxide measured from vehicle plumes. The selected pollutants and their respective instruments include ultrafine particles (FMPS3091, TSI), black carbon (PASS-3, DMT), volatile organic compounds (PTR-TOFMS8000, Ionicon Analytik), and gaseous pollutants – NOx, CO, CO2 (42i, 48c, 410i, Thermo Scientific).
Emission factors could be determined for various vehicle types including diesel and gasoline vehicles. Differences between the emission factors allowed inference of the emission control technologies used in some vehicles. Based on these preliminary data, this proposed near-road method may offer a simple approach for determining site specific factors that can be deployed in other sites or cities.