Spatial and racial/ethnic disparities in cardiovascular mortality attributable to PM 2.5 components in the contiguous United States

Long-term exposure to fine particulate matter (PM 2.5 ) 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 PM 2.5 component–attributable CVD deaths across the contiguous United States. PM 2.5 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 (NH 4 + ) and sulfate (SO 4 2− ) reductions. In 2020, high-attributable-mortality regions remained and regional disparities in PM 2.5 composition pronounced, with NH 4 + dominant in California and the East North Central, SO 4 2− in the South, and black carbon and SO 4 2− 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 PM 2.5 -attributable burden.