Short-term exposure to ozone air pollution ups risks of hospital admissions for MI, stroke

Individuals with short-term exposure to ozone (O₃) air pollution are at risk of myocardial infarction (MI) and stroke requiring hospitalization, according to a systematic review and meta-analysis.

Researchers searched for multiple online databases for epidemiological studies in which the associations between short‐term exposure to O₃ and the risks of hospital admissions for cardiovascular diseases (CVDs) were examined.

A total of 111 articles involving more than 65 million participants were included in the meta‐analysis. Forty-two effect estimates quantified the association between short‐term exposure to O₃ and the risk of hospital admissions for all‐cause CVD; nine effect estimates quantified the association with arrhythmia, seven with AF, 14 with cardiac diseases, 29 with heart failure, 36 with ischaemic heart disease, 33 with MI, and 52 with stroke.

Of the articles, 51 were from low-to-middle-income countries and 60 were from high‐income countries. Seventy-six were time‐series studies. Study quality was considered poor in two articles, moderate in 75, and high in 34.

Pooled data showed that each 10-μg/m³–increase in short‐term exposure to O₃ was associated with relative risks of 1.0084 (95 percent confidence interval [CI], 1.0019–1.0151) for hospital admissions for MI and 1.0023 (95 percent CI, 1.0012–1.0034) for hospital admissions for stroke.

In subgroup and meta‐regression analyses, study area and national economic status modified the impact of O₃ on different subtypes of CVD.