10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Characterization of the Potential Exposure of Vulnerable Communities to Traffic-related Air Pollutants in Urban Microenvironments
CHEOL H. JEONG, James M. Johnson, Cuilian Fang, Peter Murphy, Jon M. Wang, Kerolyn Shairsingh, Barbara Lachapelle, Christopher Morgan, Greg J. Evans, SOCAAR, University of Toronto
Abstract Number: 850 Working Group: Aerosol Exposure
Abstract Epidemiological and toxicological studies have demonstrated that exposure to traffic-related air pollutants (TRAP) has a wide range of adverse health impacts, especially in more susceptible population groups like children. The concentrations of TRAP (e.g. ultrafine particles (UFP), black carbon (BC), and nitrogen oxides (NOx)) vary spatially with distance from roadways due to rapid changes in atmospheric processes and meteorological conditions. In a busy downtown area, concentrations of TRAP show more localized gradients due to frequent vehicle congestions, the urban street canyon effect, and compact land and building development. For children, school location is an important determinant of exposure to traffic-related air pollution since students attending schools close to major roads can be exposed to elevated TRAP. High spatial and temporal resolution measurements are needed to evaluate personal exposure to air pollution levels in various urban environments.
To better characterize spatial gradients of TRAP in an urban environment, mobile measurements were made around busy downtown streets, urban recreational areas, and school areas in Toronto, Canada. A suite of portable devices was carried along timed and planned routes through traffic dense downtown streets up to a few kilometers, while a mobile laboratory van equipped with laboratory scale instruments was used to investigate potential exposure to TRAP around school sites. In addition to the mobile monitoring, TRAP measurements at multiple fixed monitoring stations across Toronto were made to validate the mobile monitoring data and increase the spatial and temporal resolution. The proximity of schools to major roads was determined and the relationship between TRAP concentrations measured at the school sites and the school proximity to major roads was evaluated.
Strong spatial variation of BC and UFP were found within a few kilometers in the compact downtown area and levels increased within deep urban canyons caused by tall office towers. Preliminary results indicated that BC and UFP levels increased at schools as their distance from major roadways decreased from 800 m to 100 m. UFP and BC levels at schools as far as 350 m from major highways were still higher than at a fixed site in downtown Toronto. Development of micro land use regression models for UFP and BC using the mobile and stationary monitoring data will be discussed.