title: Ambient Particulate Matter Air Pollution Exposure and Mortality in the NIH-AARP Diet and Health Cohort.
abstract: BACKGROUND
  Outdoor fine particulate matter (≤ 2.5 μm; PM2.5) has been identified as a global health threat, but the number of large U.S. prospective cohort studies with individual participant data remains limited, especially at lower recent exposures.
  
  
  OBJECTIVE
  We aimed to test the relationship between long-term exposure PM2.5 and death risk from all nonaccidental causes, cardiovascular (CVD), and respiratory diseases in 517,041 men and women enrolled in the National Institutes of Health-AARP cohort.
  
  
  METHODS
  Individual participant data were linked with residence PM2.5 exposure estimates across the continental United States for a 2000-2009 follow-up period when matching census tract-level PM2.5 exposure data were available. Participants enrolled ranged from 50 to 71 years of age, residing in six U.S. states and two cities. Cox proportional hazard models yielded hazard ratio (HR) estimates per 10 μg/m3 of PM2.5 exposure.
  
  
  RESULTS
  PM2.5 exposure was significantly associated with total mortality (HR = 1.03; 95% CI: 1.00, 1.05) and CVD mortality (HR = 1.10; 95% CI: 1.05, 1.15), but the association with respiratory mortality was not statistically significant (HR = 1.05; 95% CI: 0.98, 1.13). A significant association was found with respiratory mortality only among never smokers (HR = 1.27; 95% CI: 1.03, 1.56). Associations with 10-μg/m3 PM2.5 exposures in yearly participant residential annual mean, or in metropolitan area-wide mean, were consistent with baseline exposure model results. Associations with PM2.5 were similar when adjusted for ozone exposures. Analyses of California residents alone also yielded statistically significant PM2.5 mortality HRs for total and CVD mortality.
  
  
  CONCLUSIONS
  Long-term exposure to PM2.5 air pollution was associated with an increased risk of total and CVD mortality, providing an independent test of the PM2.5-mortality relationship in a new large U.S. prospective cohort experiencing lower post-2000 PM2.5 exposure levels.
  
  
  BACKGROUND
  Thurston GD, Ahn J, Cromar KR, Shao Y, Reynolds HR, Jerrett M, Lim CC, Shanley R, Park Y, Hayes RB. 2016. Ambient particulate matter air pollution exposure and mortality in the NIH-AARP Diet and Health cohort. Environ Health Perspect 124:484-490; http://dx.doi.org/10.1289/ehp.1509676.
authors.affiliation: Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, USA.
authors.forename: George D
authors.initials: GD
authors.lastname: Thurston
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Ahn
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Cromar
authors.forename: Yongzhao
authors.initials: Y
authors.lastname: Shao
authors.forename: Harmony R
authors.initials: HR
authors.lastname: Reynolds
authors.forename: Michael
authors.initials: M
authors.lastname: Jerrett
authors.forename: Chris C
authors.initials: CC
authors.lastname: Lim
authors.forename: Ryan
authors.initials: R
authors.lastname: Shanley
authors.forename: Yikyung
authors.initials: Y
authors.lastname: Park
authors.forename: Richard B
authors.initials: RB
authors.lastname: Hayes
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects; D002318:Cardiovascular Diseases / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects*; D011446:Prospective Studies; D012140:Respiratory Tract Diseases / Q000401:mortality; D012907:Smoking; D014481:United States / Q000453:epidemiology
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D010126:Ozone