Background

Heavy fine particulate matter with an aerodynamic diameter ≤2.5 μm (PM_2.5) pollution events continue to occur frequently in developing countries.

Objectives

The authors conducted a case-crossover study aimed at exploring the association between heavy PM_2.5 pollution events and hospital admission for cardiovascular diseases.

Methods

Hospital admissions for cardiovascular diseases were observed by Beijing Municipal Commission of Health and Family Planning Information Center from 2013 to 2017. Air pollution data were collected from the Beijing Municipal Environmental Monitoring Center. Distinct definitions were used to identify heavy and extremely heavy fine particulate pollution events. A conditional logistic regression model was used. The hospital admission burdens for cardiovascular disease were also estimated.

Results

A total of 2,202,244 hospital admissions for cardiovascular diseases and 222 days of extremely heavy PM_2.5 pollution events (PM_2.5 concentration ≥150 μg/m³) were observed. The ORs associated with extremely heavy PM_2.5 pollution events lasting for 3 days or more for total cardiovascular disease, angina, myocardial infarction, ischemic stroke, and heart failure were 1.085 (95% CI: 1.077-1.093), 1.112 (95% CI: 1.095-1.130), 1.068 (95% CI: 1.037-1.100), 1.071 (95% CI: 1.053-1.090), and 1.060 (95% CI: 1.021-1.101), respectively. The numbers and days of cardiovascular disease hospital admission annually related to extremely heavy PM_2.5 pollution events lasting for 1 day or more were 3,311 (95% CI: 2,969-3,655) and 37,020 (95% CI: 33,196-40,866), respectively.

Conclusions

Heavy and extremely heavy PM_2.5 pollution events resulted in substantial increased hospital admission risk for cardiovascular disease. With higher PM_2.5 concentration and longer duration of heavy PM_2.5 pollution events, a greater risk of cardiovascular hospital admission was observed.