Changes in PM2.5-attributable mortality in the US by sector, 2002-2019

Levels of fine particulate matter (PM2.5) air pollution in the United States have declined substantially in recent decades, yielding substantial benefits for public health. This study evaluates emission reductions across five key economic sectors—electricity, industrial, transportation, agriculture, and residential—and their impact on air quality and health. We employ a recently developed sector-specific inventory that provides emissions and their spatial disaggregation across time in a self-consistent framework. Using a national source-receptor matrix, we estimate annual PM2.5-attributable mortality and its variability spatiotemporally and by sector. We find that annual PM2.5-attributable mortality decreased 53% between 2002 (142,300 deaths) and 2019 (66,300 deaths). The largest reductions were in secondary PM2.5 from NOₓ, SOₓ, and VOC emissions from electricity and transportation. Emissions reductions from industrial and residential sectors have been more modest. In contrast, agricultural emissions, especially NH3, increased over time; the importance of agriculture among the five sectors increased from second smallest (2002) to the largest (2019). While the reductions in PM2.5-attributable mortality have been large (more than a factor of 2), future progress may need to focus greater attention on agricultural emissions, in addition to traditionally dominant sources such as transportation and industry.