Background: Fine particulate matter (PM2.5) has been previously linked to cardiovascular diseases (CVDs). PM2.5 is a mixture of components, each of which has its own toxicity profile which are not yet well understood. This study explores the relationship between long-term exposure to PM2.5 components and hospital admissions with CVDs in the Medicare population.
Methods: We analyzed data from U.S. Medicare fee-for-service beneficiaries between 2000 and 2016. Annual levels of fifteen PM2.5 components were derived from hyperlocal spatiotemporal models. Our outcomes included hospital admissions with CVDs, and more specifically with myocardial infarction, ischemic stroke, atrial fibrillation, and heart failure. A weighted quantile sum (WQS) approach was used, and stratification analyses examined effect modification by demographic and socioeconomic characteristics. We also restricted the analysis to zip code-years with PM2.5 levels below 8 μg/m3 to assess effects below current US standards.
Results: The analyses showed that higher levels of PM2.5 were associated with increased hospital admissions for CVDs, particularly heart failure. Each decile increase in PM2.5 levels increased the rate of CVD admissions by 4.1 % (95 % CI: 4.1 %-4.2 %). Key contributors to these effects included nickel and sulfate. Women and black individuals experienced higher rates of PM-associated CVD admissions, while white and non-Medicaid-eligible individuals had higher rates of stroke, atrial fibrillation, and heart failure admissions.
Conclusion: Exposure to PM2.5 components, particularly nickel and sulfate, increased the risk of CVD hospitalizations in the Medicare population, highlighting the potential to reduce CVD risk by controlling sources like fuel combustion, traffic pollution, industrial pollution, and coal use.
Keywords: Air pollution; Cardiovascular diseases; Long-term exposure; Mixtures analysis; PM2.5 components; Particulate matter.
Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.