Particulate air pollution and constituents exacerbate 10-year ASCVD risk: estimating effects of hypothetical interventions

BACKGROUND: Long-term exposure to fine particulate matter (PM2.5) increases atherosclerotic cardiovascular disease (ASCVD) risk, but evidence on its components' effects and the potential benefits achievable through PM2.5 interventions remains limited. METHODS: We used data from participants in the China Health and Retirement Longitudinal Study with low ASCVD risk at baseline. The associations between PM2.5, its components (black carbon, ammonium, nitrate, sulfate, organic matter), and 10-year ASCVD risk were evaluated using the generalized linear regression. Co-exposure effects of PM2.5 components were estimated using weighted quantile sum regression and quantile g-computation. Effects of hypothetical PM2.5 interventions (reducing annual averages to 35, 25, and 15 μg/m3) on ASCVD risk were assessed using the parametric g-formula. RESULTS: Each 10 μg/m3 increase in PM2.5 raised 10-year ASCVD risk by 18.3% (RR = 1.183, 95% CI: 1.099-1.267). Each 0.1 μg/m3 increase in black carbon and 1 μg/m3 increase in ammonium, nitrate, sulfate, and organic matter increased risks by 18.4%, 10.7%, 6.8%, 9.0%, and 6.7%, respectively. Nitrate contributed most (46.3%). Parametric g-formula estimated that reducing PM2.5 to 35, 25, and 15 μg/m3 lowered ASCVD risk by 2.78%, 3.15%, and 3.43%, respectively. Psychological conditions (e.g., depression) mediated 10-year ASCVD risk. Interaction analysis showed females were more susceptible to PM2.5 and its components. CONCLUSIONS: Long-term exposure to PM2.5 and its components elevates ASCVD risk in Chinese adults, with greater susceptibility in females. Reducing PM2.5 concentrations significantly mitigates ASCVD risk.