Determining the temporal and spatial variations of pollutants in Toronto

Abstract

This thesis aims to assess the spatial and temporal variations of pollutants in Toronto. Annual, seasonal, and monthly pollutant trends were computed from as early as 1974 to as late as the end of 2022. Decreasing NO, NO2, NOx and CO trends were found, perhaps associated with the elimination of coal-fired power plants, and vehicular technology improvements, leading to emissions reductions. Applying two different techniques to trace pollutant measurements from air quality stations upwind, NO, NO2, NOx , and CO concentrations were found to be relatively high around Downsview and Pearson Airport, as well as the York University power plant. Additionally, relatively high NO2 and NOx levels were denoted around Highway 401, suggesting vehicular and aircraft emissions sources. The greatest concentrations of PM2.5, PM10, O3, and SO2 were concluded to originate from outside the city. Income information was obtained by neighborhood and related to the spatial distribution of pollutants in Toronto. A negative relationship was found between NO and NOx levels and income. This is because the lowest and highest income neighborhoods (generally located in north and south Toronto, respectively) mostly coincided with relatively high and low NO, NOx concentrations, respectively. TROPOMI satellite measurements over a gridded plane in Toronto also display the highest and lowest NO2 and HCHO levels over Pearson Airport and Lake Ontario.