Keywords: air pollution, epidemiology, environment, multicity
Particulate matter (PM) air pollution is a complex mixture of chemicals emitted from sources including coal-fired power plants, wildfires, and traffic. Though exposure to total PM mass is associated with mortality and morbidity, the toxicity of PM may vary based on its generating sources. In the US, public health recommendations are generally focused on reducing total PM exposure, but source-specific recommendations may further protect health. Developing source-specific recommendations is challenging because PM exposure is measured at stationary monitors that do not directly capture information about source-specific exposure. Previously developed approaches for estimating source-specific exposure are generally not scalable to large, multicity studies; however multicity studies are necessary to determine how health effects of PM vary between cities by its generating sources. We develop approaches for comparing sources across multiple cities, and these approaches allow us to estimate source-specific health effects. Approaches for conducting multicity studies of source-specific PM and health are necessary to determine whether public health recommendations should vary by source.