Clearing the air: Which pollution source matters most for health?

Air pollution remains a significant public health challenge, contributing to substantial morbidity and mortality. The aim of this study is to identify effective intervention strategies for mitigating air pollution and its health effects in southern Quebec.

We employ the Polair3D chemical transport model to estimate population-weighted concentrations of fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃) at the census division level under four scenarios: replacing residential wood stoves with U.S. Environmental Protection Agency (EPA)-certified models (EPA), eliminating industrial emissions (IND), full vehicle electrification (EV), and removing emissions from refineries and smelters (RS). Health impacts were quantified with the Air Quality Benefits Assessment Tool for chronic PM_2.5 exposure and chronic NO₂ exposure, in addition to the commonly assessed acute NO₂ exposure and acute O₃ exposure.

All scenarios reduced air pollutant concentrations and associated mortality to varying degrees. The EPA and EV interventions are the most effective in reducing mortality, lowering deaths attributable to pollutants by 15.26% (789 deaths from 5169 to 4380) and 16.13% (834 deaths from 5169 to 4335), respectively. The EPA scenario yields the greatest reduction in PM_2.5-related mortality, while the EV scenario provides the most benefit for NO₂-related mortality.

Targeted interventions can significantly reduce air pollution-related mortality. Replacing residential wood stoves and fully electrifying vehicles are particularly effective, with distinct benefits for PM_2.5- and chronic NO₂-related health outcomes. A multi-sectoral approach is essential to maximize public health gains.