Impact of Short-Term Exposure to Ozone on Hospital Admissions for Multiple Cardiovascular Diseases: A Systematic Review and Meta-Analysis.

Background: The associations between short-term exposure to ambient ozone (O) pollution and the risks of hospital admissions (an indicator for morbidity) for different subtypes of cardiovascular disease (CVD) remain unclear. Therefore, this study aimed to evaluate the associations between short-term exposure to O and the risks of hospital admissions for all-cause CVD, arrhythmia, atrial fibrillation, cardiac diseases, heart failure, ischemic heart disease, myocardial infarction (MI), and stroke.

Methods: Four electronic databases, including PubMed, Web of Science, Scopus, and Embase, were searched for articles published up to December 21, 2023. Epidemiological studies reporting the associations between short-term exposure to O and the risks of hospital admissions for CVDs were included on the basis of stringent inclusion and exclusion criteria. The random-effect model was applied to estimate pooled relative risk and 95% CIs. To identify potential effect modifiers, subgroup and meta-regression analyses were also performed.

Results: A total of 111 articles with >65 million participants were included in the meta-analysis. For a 10 μg/m increase in short-term exposure to O, the relative risks of hospital admissions for MI and stroke were 1.0084 (95% CI, 1.0019-1.0151) and 1.0023 [95% confidence interval (CI), 1.0012-1.0034], respectively. Subgroup and meta-regression analyses revealed that study area and national economic status could influence the impact of O on different subtypes of CVD.

Conclusions: This meta-analysis provides compelling evidence for the adverse effects of short-term exposure to ambient O pollution on the risks of hospital admissions for MI and stroke.