Long-Term Effects of High Exposure to Ambient Fine Particulate Matter on Coronary Heart Disease Incidence: A Population-Based Chinese Cohort Study

Evidence of long-term effects of high exposure to ambient fine particulate matter (PM_2.5) on coronary heart disease (CHD) remains limited. We incorporated the high-resolution satellite-based PM_2.5 estimates with a large-scale, population-based Chinese cohort comprising 118 229 individuals, to assess the CHD risk of long-term exposure to high PM_2.5. During the follow-up of 908 376 person-years, 1586 incident CHD cases were identified. The long-term average PM_2.5 concentration for study population was 64.96 μg/m³, ranging from 31.17 to 96.96 μg/m³. For an increment of 10 μg/m³ in PM_2.5, the multivariate-adjusted hazard ratios (HRs) were 1.43 (95% confidence interval [CI]: 1.35-1.51) for total CHD, 1.45 (95% CI: 1.36-1.56) for nonfatal CHD, and 1.38 (95% CI: 1.25-1.53) for fatal CHD, respectively. The effects were different across specific CHD outcomes, with greater effects for unstable angina (HR, 1.71 [95% CI, 1.56-1.88]), and weaker effects for acute myocardial infarction (HR, 1.28 [95% CI, 1.19-1.39]) and other CHD (HR, 1.27 [95% CI, 1.10-1.48]). The exposure-response curve suggested that HRs increased with elevated PM_2.5 concentration over the entire exposure range. Elderly and hypertensive individuals were more susceptible to PM_2.5-induced CHD. Our findings demonstrate the adverse health effects of severe air pollution and highlight the potential health benefits of air quality improvement.