title: Long-term exposure to traffic-related air pollution and the risk of coronary heart disease hospitalization and mortality.
abstract: BACKGROUND
  Epidemiologic studies have demonstrated that exposure to road traffic is associated with adverse cardiovascular outcomes.
  
  
  OBJECTIVE
  We aimed to identify specific traffic-related air pollutants that are associated with the risk of coronary heart disease (CHD) morbidity and mortality to support evidence-based environmental policy making.
  
  
  METHODS
  This population-based cohort study included a 5-year exposure period and a 4-year follow-up period. All residents 45-85 years of age who resided in Metropolitan Vancouver during the exposure period and without known CHD at baseline were included in this study (n=452,735). Individual exposures to traffic-related air pollutants including black carbon, fine particles [aerodynamic diameter ≤ 2.5 µm (PM(2.5))], nitrogen dioxide (NO(2)), and nitric oxide were estimated at residences of the subjects using land-use regression models and integrating changes in residences during the exposure period. CHD hospitalizations and deaths during the follow-up period were identified from provincial hospitalization and death registration records.
  
  
  RESULTS
  An interquartile range elevation in the average concentration of black carbon (0.94 × 10(-5)/m filter absorbance, equivalent to approximately 0.8 µg/m(3) elemental carbon) was associated with a 3% increase in CHD hospitalization (95% confidence interval, 1-5%) and a 6% increase in CHD mortality (3-9%) after adjusting for age, sex, preexisting comorbidity, neighborhood socioeconomic status, and copollutants (PM(2.5) and NO(2)). There were clear linear exposure-response relationships between black carbon and coronary events.
  
  
  CONCLUSIONS
  Long-term exposure to traffic-related fine particulate air pollution, indicated by black carbon, may partly explain the observed associations between exposure to road traffic and adverse cardiovascular outcomes.
authors.affiliation: School of Environmental Health, University of British Columbia, Vancouver, British Columbia, Canada. wenqi.gan@gmail.com
authors.forename: Wen Qi
authors.initials: WQ
authors.lastname: Gan
authors.forename: Mieke
authors.initials: M
authors.lastname: Koehoorn
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Davies
authors.forename: Paul A
authors.initials: PA
authors.lastname: Demers
authors.forename: Lillian
authors.initials: L
authors.lastname: Tamburic
authors.forename: Michael
authors.initials: M
authors.lastname: Brauer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D003327:Coronary Disease / Q000453:epidemiology* / Q000401:mortality; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000032:analysis; D009589:Nitrogen Oxides / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D018570:Risk Assessment; D053260:Soot / Q000032:analysis; D014186:Transportation / Q000706:statistics & numerical data
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D053260:Soot; D009585:Nitrogen Dioxide