Source-Specific PM and Atherosclerotic Cardiovascular Disease Mortality.

BACKGROUND

Fine particulate matter (PM) exposure is adversely linked to atherosclerotic cardiovascular disease (ASCVD). However, most studies focused on PM mass rather than its chemical composition and specific sources. Particulate pollution sources can have distinct, cumulative, and potentially synergistic health impacts. We investigated the associations of source-specific PM exposure with ASCVD mortality in the United States, considering the combined associations and regional variations.

METHODS

We used data from the Centers for Medicare & Medicaid Services (including data from 65,838,403 participants) from 2000 to 2016. We estimated PM exposure using machine-learning models and attributed components to five source categories. We used Poisson survival models to assess the associations with the source categories.

RESULTS

Higher ASCVD mortality rate (rate ratio [95% confidence interval (CI)] per interquartile range increase) was associated with oil combustion (1.051 [1.049 to 1.052]), industrial pollution (1.054 [1.052 to 1.056]), coal and biomass burning (1.065 [1.062 to 1.067]), and motor vehicle pollution (1.044 [1.042 to 1.046]). These associations persisted even after limiting our sample to ZIP code-years with PM<9 μg/m - the current National Ambient Air Quality Standard. In these areas the observed rate ratio for a one-unit increase in PM mass was 1.028 (95% CI, 1.026 to 1.029).

CONCLUSIONS

We found higher ASCVD mortality rate associated with PM, with differential effects across sources. These data highlight the importance of considering local population characteristics and exposure patterns when assessing health risks associated with PM.