AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Evolution of Traffic-Related Atmospheric Pollutants Near Roadways
CHEOL-HEON JEONG, Greg J. Evans, John Liggio, Jeremy Wentzell, Ralf Staebler, Jeff Brook, SOCAAR, University of Toronto
Abstract Number: 250 Working Group: Urban Aerosols
Abstract Traffic-related atmospheric pollutants (TRAP) are believed to adversely impact the health of populations living and working near roadways. Estimation of the exposure of these populations to TRAP is a challenging task as concentrations of TRAP varies both spatially and temporally.
To characterize the spatial and temporal variations of TRAP in near-road environments, the evolution of ambient pollutants near a highway was investigated in Toronto in the summer of 2010 through the Fast Evolution of Vehicle Emissions near Roadways (FEVER) campaign. For this study, the U of T mobile laboratory (MAPLE) was deployed to measure the decay gradients of TRAP as a function of the distance from the highway. The study included mobile measurements of particle size distributions and chemical composition using a Fast Mobility Particle Spectrometer (FMPS), an Aerodynamic Particle Sizer (APS), an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS), an Aethalometer, a particle-bound PAH (p-PAH) monitor including trace gases and meteorology. The ATOFMS was equipped with an automated thermo-denuder (TD) allowing rapid alternation between TD-treated and untreated sampling, to characterize variation of non-volatile particle composition. In addition, the micro-scale gradient of ultrafine particles (UFP) within 20 m from the highway was evaluated using two FMPSs with the TD system. Preliminary results indicate that downwind UFP, p-PAH, and black carbon concentrations at 30 m distance from the highway was 3-6 times higher than average concentrations measured downwind at 270 m. For near-roadside (< 20 m) particles, volatility measurements showed a loss of ~60% by number and ~80% by volume with a heating of 250 $^oC. High-time resolution mobile measurements of TRAP spatial patterns upwind and downwind of a highway will be discussed.