Environmental Injustice in Peel Region: A Cross-Sectional Analysis of Air Pollution and Social Vulnerability

Abstract

Background: Nitrogen dioxide (NO2), a traffic-related air pollutant, is co-emitted with greenhouse gasses that contribute to climate change and negatively affect health. This research examines the relationship between air pollution exposure and social vulnerability to determine whether communities at a social disadvantage experience environmental injustice. Methods: The 2016 census measures for Peel Region were assessed. Peel Region has 1,381,739 people across Mississauga, Brampton, and Caledon; the spatial unit of analysis was the dissemination area (DA) with an average size of 837 people in Peel. Average ambient NO2 concentrations for 2016 came from the Canadian Urban Environmental Health Research Consortium and resampled to DAs. Social disadvantage was defined by the Ontario Marginalization Index (ON-Marg). Measures within index components came from the Canadian census. Environmental injustice was identified through correlation analysis between ON-Marg and NO2 exposure and an analysis of index components with exposure. Results: The 2016 annual NO2 concentrations were positively correlated with the overall ON-Marg quintiles (Spearman: 0.34, p < .001, 95% CI 0.29 to 0.37). The components and their correlations with NO2 were residential instability (Spearman: 0.37, p < .001, 95% CI 0.33 to 0.42), material deprivation (Spearman: 0.15, p < .001, 95% CI 0.10 to 0.19), dependency (Spearman: 0.31, p < .001, 95% CI 0.26 to 0.35), and ethnic concentration (Spearman: −0.06, p = .02, 95% CI −0.11 to −0.01). Conclusions: In Peel Region, a correlation exists between social vulnerability and air pollution, indicating inequitable exposure to NO2. Marginalized communities may not be able to choose their living environment. Environmental justice research in the context of NO2 will support policy aiming to reduce inequitable exposure.