The relationship between particulate air pollution and emergency hospital visits for hypertension in Beijing, China

Background: A number of epidemiological studies have examined the adverse effect of air pollution on mortality and morbidity. Also, several studies have investigated the associations between air pollution and specific-cause diseases including arrhythmia, myocardial infarction, and heart failure. However, little is known about the relationship between air pollution and the onset of hypertension. Objective: To explore the risk effect of particulate matter air pollution on the emergency hospital visits (EHVs) for hypertension in Beijing, China. Methods: We gathered data on daily EHVs for hypertension, fine particulate matter less than 2.5μm in aerodynamic diameter (PM_2.5), particulate matter less than 10μm in aerodynamic diameter (PM₁₀), sulfur dioxide, and nitrogen dioxide in Beijing, China during 2007. A time-stratified case-crossover design with distributed lag model was used to evaluate associations between ambient air pollutants and hypertension. Daily mean temperature and relative humidity were controlled in all models. Results: There were 1,491 EHVs for hypertension during the study period. In single pollutant models, an increase in 10μg/m³ in PM_2.5 and PM₁₀ was associated with EHVs for hypertension with odds ratios (overall effect of five days) of 1.084 (95% confidence interval (CI): 1.028, 1.139) and 1.060% (95% CI: 1.020, 1.101), respectively. Conclusion: Elevated levels of ambient particulate matters are associated with an increase in EHVs for hypertension in Beijing, China.