Short-term residential exposure to air pollution and risk of acute myocardial infarction deaths at home in China

Abstract

Air pollution remains a major threat to cardiovascular health and most acute myocardial infarction (AMI) deaths occur at home. However, currently established knowledge on the deleterious effect of air pollution on AMI has been limited to routinely monitored air pollutants and overlooked the place of death. In this study, we examined the association between short-term residential exposure to China's routinely monitored and unmonitored air pollutants and the risk of AMI deaths at home. A time-stratified case-crossover analysis was undertaken to associate short-term residential exposure to air pollution with 0.1 million AMI deaths at home in Jiangsu Province (China) during 2016-2019. Individual-level residential exposure to five unmonitored and monitored air pollutants including PM₁ (particulate matter with an aerodynamic diameter ≤ 1 μm) and PM_2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm), SO₂ (sulfur dioxide), NO₂ (nitrogen dioxide), and O₃ (ozone) was estimated from satellite remote sensing and machine learning technique. We found that exposure to five air pollutants, even below the recently released stricter air quality standards of the World Health Organization (WHO), was all associated with increased odds of AMI deaths at home. The odds of AMI deaths increased by 20% (95% confidence interval: 8 to 33%), 22% (12 to 33%), 14% (2 to 27%), 13% (3 to 25%), and 7% (3 to 12%) for an interquartile range increase in PM₁, PM_2.5, SO₂, NO₂, and O₃, respectively. A greater magnitude of association between NO₂ or O₃ and AMI deaths was observed in females and in the warm season. The greatest association between PM₁ and AMI deaths was found in individuals aged ≤ 64 years. This study for the first time suggests that residential exposure to routinely monitored and unmonitored air pollutants, even below the newest WHO air quality standards, is still associated with higher odds of AMI deaths at home. Future studies are warranted to understand the biological mechanisms behind the triggering of AMI deaths by air pollution exposure, to develop intervention strategies to reduce AMI deaths triggered by air pollution exposure, and to evaluate the cost-effectiveness, accessibility, and sustainability of these intervention strategies.

Keywords: Acute myocardial infarction; Air pollution; Cardiovascular disease; Gaseous pollutant; Particulate matter.