Using spatio-temporal modeling for exposure assessment in an investigation of fine particulate air pollution and cardiovascular mortality

摘要

Background: U.S. urban air quality has improved dramatically over the past decades. We evaluated acute effects of fine particulate matter (PM_(2.5)) on cardiovascular (CVD) mortality among residents of Allegheny County in SW Pennsylvania (1999-2011) using spatio-temporal modeling of air pollutants (AP) to reduce misclassification error in exposure assessment. Methods: Spatio-temporal kriging of daily PM_(2.5) and ozone (O_3) was used to produce daily exposure estimates at the residence ZIP code. Time-stratified case-crossover analysis was conducted to examine short-term effects of PM_(2.5) on CVD mortality, adjusting for O_3 and apparent mean temperature. We studied both single and distributed lags for days 0-5. All CVD mortality and subcategories of ischemic heart disease (IHD), acute myocardial infarction, cerebrovascular disease, peripheral vascular disease (PVD), heart failure and cardiac arrhythmia were examined. Results: A total of 62,135 deaths were identified. We found significant associations of PM_(2.5) with IHD and PVD mortality at lag day 5: (2.1% (95% CI, 0.2-4.1%) and (7.6%, 95% CI, 0.05-15.7%) per 10 μg/m~3 increase of PM_(2.5) in single lag models and for IHD in distributed lag models. There were no statistically significant associations with PM_(2.5) for any of the other outcomes. Conclusions: The application of finer scale geographically resolved AP exposures made it possible to study acute effects of PM_(2.5) on CVD mortality in a large metropolitan area. Our study results demonstrated the continued presence of a dose response relationship of increased risk of CVD mortality within this lower range of PM_(2.5) exposure.