Hayes, Richard B, Lim, Chris, Zhang, Yilong, Cromar, Kevin, Shao, Yongzhao, Reynolds, Harmony R, Silverman, Debra T, Jones, Rena R, Park, Yikyung, Jerrett, Michael, Ahn, Jiyoung, and Thurston, George D
BackgroundAmbient air pollution is a modifiable risk factor for cardiovascular disease, yet uncertainty remains about the size of risks at lower levels of fine particulate matter (PM2.5) exposure which now occur in the USA and elsewhere.MethodsWe investigated the relationship of ambient PM2.5 exposure with cause-specific cardiovascular disease mortality in 565477 men and women, aged 50 to 71 years, from the National Institutes of Health-AARP Diet and Health Study. During 7.5 x 106 person-years of follow up, 41286 cardiovascular disease deaths, including 23328 ischaemic heart disease (IHD) and 5894 stroke deaths, were ascertained using the National Death Index. PM2.5 was estimated using a hybrid land use regression (LUR) geostatistical model. Multivariate Cox regression models were used to estimate relative risks (RRs) and 95% confidence intervals (CI).ResultsEach increase of 10 μg/m3 PM2.5 (overall range, 2.9-28.0 μg/m3) was associated, in fully adjusted models, with a 16% increase in mortality from ischaemic heart disease [hazard ratio (HR) 1.16; 95% CI 1.09-1.22] and a 14% increase in mortality from stroke (HR 1.14; CI 1.02-1.27). Compared with PM2.5 exposure