title: Modeling the intraurban variability of ambient traffic pollution in Toronto, Canada.
abstract: The objective of this paper is to model determinants of intraurban variation in ambient concentrations of nitrogen dioxide (NO2) in Toronto, Canada, with a land use regression (LUR) model. Although researchers have conducted similar studies in Europe, this work represents the first attempt in a North American setting to characterize variation in traffic pollution through the LUR method. NO2 samples were collected over 2 wk using duplicate two-sided Ogawa passive diffusion samplers at 95 locations across Toronto. Independent variables employed in subsequent regression models as predictors of NO2 were derived by the Arc 8 geographic information system (GIS). Some 85 indicators of land use, traffic, population density, and physical geography were tested. The final regression model yielded a coefficient of determination (R2) of .69. For the traffic variables, density of 24-h traffic counts and road measures display positive associations. For the land use variables, industrial land use and counts of dwellings within 2000 m of the monitoring location were positively associated with NO2. Locations up to 1500 m downwind of major expressways had elevated NO2 levels. The results suggest that a good predictive surface can be derived for North American cities with the LUR method. The predictive maps from the LUR appear to capture small-area variation in NO2 concentrations. These small-area variations in traffic pollution are probably important to the exposure experience of the population and may detect health effects that would have gone unnoticed with other exposure estimates.
authors: Division of Environmental Health Sciences School of Public Health, University of California-Berkeley, Berkeley, California 94720-7360, USA. jerrett@berkeley.edu
authors: M
authors: M
authors: Jerrett
authors: M A
authors: MA
authors: Arain
authors: P
authors: P
authors: Kanaroglou
authors: B
authors: B
authors: Beckerman
authors: D
authors: D
authors: Crouse
authors: N L
authors: NL
authors: Gilbert
authors: J R
authors: JR
authors: Brook
authors: N
authors: N
authors: Finkelstein
authors: M M
authors: MM
authors: Finkelstein
mesh_terms: D000397:Air Pollution / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D005544:Forecasting; D008962:Models, Theoretical; D018986:Motor Vehicles; D009585:Nitrogen Dioxide / Q000032:analysis; D009864:Ontario; D012044:Regression Analysis; D015203:Reproducibility of Results
chemical_list: D009585:Nitrogen Dioxide