AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Short and Long Term Temporal Patterns and Chemical Profile of Airborne Urban Road Dust near a Major Road
CHEOL-HEON JEONG, Nathan Hilker, Jon M Wang, Angela Huang, Dennis Herod, Ewa Dabek-Zlotorzynska, Luc White, Tony Munoz, Greg J. Evans, SOCAAR, University of Toronto
Abstract Number: 245 Working Group: Urban Aerosols
Abstract Urban road dust is a complex mixture of mineral dust and metals from non-exhaust emissions originating from paved road surface, brake, and tire wear. This dust can be a major source of airborne metals in urban areas and may contribute to oxidative stress related adverse health impacts. Due to the strong influence of meteorology and traffic patterns on the emission, re-suspension, and mitigation of urban road dusts, the temporal and spatial variations of the non-tailpipe sources can be highly varied. However, the short-term and long-term temporal variability and chemical profile of urban road dusts in PM2.5 are not well characterized.
The hourly contribution of urban road dust to PM2.5 beside a major urban road was elucidated by applying a receptor model, Positive Matrix Factorization (PMF). Trace metals were measured by a continuous metals monitor (Copper Environ., Xact 625) in late winter and spring at a near road site in Toronto, located 15 m from a roadway, and at an urban background site located 5 km south of the near road site. In addition, long-term variation in the contribution of road dust was elucidated by applying PMF to twenty-four hour integrated PM2.5 chemical speciation data collected from 2004 to 2014. Road dust episodic days were further identified and characterized by analyzing meteorological conditions, traffic patterns, and the mixing state of traffic-related road dust particles obtained by using an aerosol time-of-flight mass spectrometer (ATOFMS, TSI 3800). In this presentation, the chemical profiles and temporal patterns for road dust revealed through these three complementary approaches will be compared and contrasted.