Spatial and racial/ethnic disparities in cardiovascular mortality attributable to PM2.5 components in the contiguous United States

Long-term exposure to fine particulate matter (PM2.5) is a well-established risk factor for cardiovascular disease (CVD) mortality, yet the contributions of its components remain unclear, particularly across geographic regions and racial/ethnic groups. We extended the generalized weighted quantile sum regression model by incorporating two-way fixed effects (gWQS-feglm) to quantify PM2.5 component-attributable CVD deaths across the contiguous United States. PM2.5 component-attributable CVD deaths declined from 42,200 (28,200,57,600) in 2001 to 23,500 (15,700,32,100) in 2020, driven by ammonium (NH4+) and sulfate (SO42-) reductions. In 2020, high-attributable-mortality regions remained and regional disparities in PM2.5 composition pronounced, with NH4+ dominant in California and the East North Central, SO42- in the South, and black carbon and SO42- in the Middle Atlantic. Racial/ethnic disparities persisted, with non-Hispanic Blacks and Hispanics experiencing slower attributable-mortality declines compared with non-Hispanic whites. Our findings highlight the importance of targeted interventions based on components to address disparities in PM2.5-attributable burden.