Associations between long-term air pollution exposure and the incidence of cardiovascular diseases among American older adults

• Authors: Tingfan Jin, Harvard T.H. Chan School of Public Health; Qian Di, Tsinghua University; Weeberb J Réquia, Fundação Getúlio Vargas, Brasília, Distrito Federal, Brazil; Mahdieh Danesh Yazdi, Stony Brook University; Edgar Castro, Harvard T.H. Chan School of Public Health; Tszshan Ma, Emory University; Yifan Wang, Emory University; Haisu Zhang, Emory University; Liuhua Shi, Emory University; Joel Schwartz, Harvard T.H. Chan School of Public Health
• Journal Title: ENVIRONMENT INTERNATIONAL
• Volume: Volume 170
• Publisher: PERGAMON-ELSEVIER SCIENCE LTD | 2022-10-22, Pages 107594-107594
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.envint.2022.107594
• Subjects: Environmental Sciences; Health Sciences, Public Health
• Keywords: Science & Technology; Life Sciences & Biomedicine; Environmental Sciences; Environmental Sciences & Ecology; PM2; 5; NO2; Warm-seasonO3; Atrial fibrillation; Congestive heart failure; Stroke; HEART-FAILURE; EUROPEAN COHORTS; PM2.5 EXPOSURE; MORTALITY; HOSPITALIZATION; STROKE; INFLAMMATION; VIOLENCE; STATINS

Abstract

Background & aim: Numerous studies have linked air pollution with cardiovascular diseases. Fewer studies examined the associations at low concentration levels or assessed potential modifiers. Some investigations only examined hospitalizations, which can miss incident cases. This study aims to address these gaps through a nationwide cohort study of Medicare enrollees. Methods: Our study cohort comprise all Medicare enrollees (≥65 years old) continuously enrolled in the fee-for-service program and both Medicare part A and B across the contiguous U.S. from 2000 to 2016. We examined the associations of population-weighted ZIP code-level annual average PM2.5, NO2, and warm-season O3 (May-October), with the first diagnoses of atrial fibrillation (AF), congestive heart failure (CHF), and stroke. We fit multi-pollutant Cox proportional hazards models adjusted for individual demographic characteristics and area-level covariates. We further examined these associations at low pollutant concentration levels and the potential effect modifications by race/ethnicity and comorbidities (diabetes, hypertension, hyperlipidemia). Results: Elevated PM2.5 and NO2 levels were associated with increased incidence of AF, CHF, and stroke. For each 1 μg/m3 increase in annual PM2.5, hazard ratios (HRs) were 1.0059 (95%CI: 1.0054-1.0064), 1.0260 (95%CI: 1.0256-1.0264), and 1.0279 (95%CI: 1.0274-1.0284), respectively. For each1 ppb increase in annual NO2, HRs are 1.0057 (95%CI: 1.0056-1.0059), 1.0112 (95%CI: 1.0110-1.0113), and 1.0095 (95%CI: 1.0093-1.0096), respectively. For warm-season O3, each 1 ppb increase was associated with increased incidence of CHF (HR=1.0035, 95%CI: 1.0033–1.0037) and stroke (HR=1.0026, 95%CI: 1.0023–1.0028). Larger magnitudes of HRs were observed when restricted to pollutants levels lower than NAAQS standards. Generally higher risks were observed for Black people and diabetics. Conclusions: Long-term exposure to PM2.5, NO2, and warm-season O3 were associated with increased incidence of cardiovascular diseases, even at low pollutant concentration levels. Black people and people with diabetes were found to be vulnerable populations.