AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Real-World Vehicle Emission Factors of Gaseous and Particle Phase Pollutants from High Time Resolution Near-Road Measurements
JON M WANG, Cheol-Heon Jeong, Naomi Zimmerman, Nathan Hilker, Robert Healy, Greg J. Evans, SOCAAR, University of Toronto
Abstract Number: 413 Working Group: Urban Aerosols
Abstract Vehicles are an important contributor to outdoor urban air pollution. Exposure to traffic-related pollutants has been associated with negative impacts to human health and the environment. Emission factors (EFs) compiled from engine dynamometer studies are often used to model the impacts of vehicle emissions on air quality. However, dynamometer studies are limited, making it difficult to predict the variability of fleet emissions, especially for atypical heavy emitters. In order to better assess the representativeness of dynamometer-based EFs in real-world settings, EFs must be measured under ambient conditions for the in-use vehicle fleet.
The aim of this study is to apply near-road region measurements at a field site in downtown Toronto, Canada to calculate fuel-based EFs of passing vehicles for traffic-related pollutants. The selected pollutants and their respective instruments include ultrafine particles (FMPS 3091, TSI Inc), black carbon (PASS-3, DMT), volatile organic compounds (PTR-TOFMS 8000, Ionicon Analytik), and gaseous pollutants – NOx, CO, CO2 (42i, 48c, 410i, Thermo Scientific) all measured at high time resolution (0.5-1 Hz). The high time resolution allows for analysis of pollutant emissions on a plume-by-plume basis. Additionally, the climate in Toronto allows for comparison of EFs measured in vastly different seasons.
This study has provided EFs for both regulated and unregulated vehicle-related pollutants. The underlying methodology will be described along with associations of the EFs observed with local meteorology and vehicle classification (e.g. cars and trucks).