Abstract
Fine particulate matter (PM(2.5)) is a leading risk factor for morbidity and mortality worldwide. Recent studies have shown substantial heterogeneity in exposure to PM(2.5) within populations, with socially disadvantaged subgroups exhibiting disproportionally higher exposure. However, the extent to which reductions in PM(2.5) and its components may differentially affect these subgroups remains unclear. Leveraging state-of-the-art exposure surfaces that simulate annual reductions in total and compositional PM(2.5) from major emission sectors under two policy scenarios (20% and 100%), based on satellite observations and a global chemical transport model, we characterized the expected reductions in total and compositional population-weighted PM(2.5) exposure by selected subgroups for 2007 and 2016. Under both scenarios, we found that certain subgroups, particularly low-income people, immigrants, and racialized groups, would experience larger reductions in exposure to total and compositional PM(2.5). The largest decreases were associated with nitrates, sulfates, and ammonia from agriculture, nitrates and black carbon from transportation, and organic matter from residential wood combustion. These findings have important implications for PM(2.5) mitigation strategies aimed at reducing population exposure and associated disparities in Canada.