title: Long-Term Exposure to NO2 and Ozone and Hypertension Incidence in the Black Women's Health Study.
abstract: BACKGROUND
  Evidence shows that exposure to air pollutants can increase blood pressure in the short and long term. Some studies show higher levels of hypertension prevalence in areas of high pollution. Few data exist on the association of air pollution with hypertension incidence. The purpose of the present study was to prospectively assess the associations of the traffic-related nitrogen dioxide (NO2) and of ozone with the incidence of hypertension in the Black Women's Health Study (BWHS), a large cohort study of African American women.
  
  
  METHODS
  We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CI) for hypertension associated with exposure to NO2 and ozone among 33,771 BWHS participants. NO2 and ozone levels at participant residential locations were estimated with validated models.
  
  
  RESULTS
  From 1995 to 2011, 9,570 incident cases of hypertension occurred in a total of 348,154 person-years (median follow-up time, 11 years). The multivariable HRs per interquartile range of NO2 (9.7 ppb) and ozone (6.7 ppb) were 0.92 (95% CI = 0.86, 0.98) and 1.09 (95% CI = 1.00, 1.18).
  
  
  CONCLUSIONS
  In this large cohort of African American women, higher ozone levels were associated with an increase in hypertension incidence. Higher NO2 levels were not associated with greater hypertension incidence; indeed, incidence was lower at higher NO2 levels.
authors.affiliation: Slone Epidemiology Center at Boston University, Boston, MA, USA.
authors.forename: Patricia F
authors.initials: PF
authors.lastname: Coogan
authors.affiliation: Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Laura F
authors.initials: LF
authors.lastname: White
authors.affiliation: Slone Epidemiology Center at Boston University, Boston, MA, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Yu
authors.affiliation: Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brook
authors.affiliation: Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Burnett
authors.affiliation: Civil and Environmental Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Julian D
authors.initials: JD
authors.lastname: Marshall
authors.affiliation: Slone Epidemiology Center at Boston University, Boston, MA, USA.
authors.forename: Traci N
authors.initials: TN
authors.lastname: Bethea
authors.affiliation: Slone Epidemiology Center at Boston University, Boston, MA, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Rosenberg
authors.affiliation: Department of Environmental Health Sciences and Center for Occupational and Environmental Health, Fielding School of Public Health, University of California, Los Angeles, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Jerrett
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D000397:Air Pollution / Q000706:statistics & numerical data*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D015994:Incidence; D008875:Middle Aged; D015999:Multivariate Analysis; D009585:Nitrogen Dioxide; D010126:Ozone; D016016:Proportional Hazards Models; D013997:Time Factors; D055815:Young Adult
chemical_list: D010126:Ozone; D009585:Nitrogen Dioxide
keywords: African American; air pollution; blood pressure; hypertension; hypertension incidence; women.