Background: Long-term fine particulate matter (PM2.5) exposure is linked with cardiovascular disease, and disadvantaged status may increase susceptibility to air pollution-related health effects. In addition, there are concerns that this association may be partially explained by confounding by socioeconomic status (SES).
Objectives: We examined the roles that individual- and neighborhood-level SES (NSES) play in the association between PM2.5 exposure and cardiovascular disease.
Methods: The study population comprised 51,754 postmenopausal women from the Women’s Health Initiative Observational Study. PM2.5 concentrations were predicted at participant residences using fine-scale regionalized universal kriging models. We assessed individual-level SES and NSES (Census-tract level) across several SES domains including education, occupation, and income/wealth, as well as through an NSES score, which captures several important dimensions of SES. Cox proportional-hazards regression adjusted for SES factors and other covariates to determine the risk of a first cardiovascular event.
Results: A 5 μg/m3 higher exposure to PM2.5 was associated with a 13% increased risk of cardiovascular event [hazard ratio (HR) 1.13; 95% confidence interval (CI): 1.02, 1.26]. Adjustment for SES factors did not meaningfully affect the risk estimate. Higher risk estimates were observed among participants living in low-SES neighborhoods. The most and least disadvantaged quartiles of the NSES score had HRs of 1.39 (95% CI: 1.21, 1.61) and 0.90 (95% CI: 0.72, 1.07), respectively.
Conclusions: Women with lower NSES may be more susceptible to air pollution-related health effects. The association between air pollution and cardiovascular disease was not explained by confounding from individual-level SES or NSES.
1Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington, USA; 2Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington, USA; 3RAND Corporation, Santa Monica, California, USA; 4Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, USA; 5RAND Corporation, Arlington, Virginia, USA; 6Department of Medicine, Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, California, USA; 7Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, North Carolina, USA; 8Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
Recommended Citation:
Gloria C. Chi,1 Anjum Hajat,2 Chloe E. Bird,et al. Individual and Neighborhood Socioeconomic Status and the Association between Air Pollution and Cardiovascular Disease[J]. Environmental Health Perspectives,2016-01-01,Volume 124(Issue 12):1840