title: Long-term traffic air and noise pollution in relation to mortality and hospital readmission among myocardial infarction survivors.
abstract: BACKGROUND
  There is relatively little evidence of health effects of long-term exposure to traffic-related pollution in susceptible populations. We investigated whether long-term exposure to traffic air and noise pollution was associated with all-cause mortality or hospital readmission for myocardial infarction (MI) among survivors of hospital admission for MI.
  
  
  METHODS
  Patients from the Myocardial Ischaemia National Audit Project database resident in Greater London (n = 1 8,138) were followed for death or readmission for MI. High spatially-resolved annual average air pollution (11 metrics of primary traffic, regional or urban background) derived from a dispersion model (resolution 20 m × 20 m) and road traffic noise for the years 2003-2010 were used to assign exposure at residence. Hazard ratios (HR, 95% confidence interval (CI)) were estimated using Cox proportional hazards models.
  
  
  RESULTS
  Most air pollutants were positively associated with all-cause mortality alone and in combination with hospital readmission. The largest associations with mortality per interquartile range (IQR) increase of pollutant were observed for non-exhaust particulate matter (PM(10)) (HR = 1.05 (95% CI 1.00, 1.10), IQR = 1.1 μg/m(3)); oxidant gases (HR = 1.05 (95% CI 1.00, 1.09), IQR = 3.2 μg/m(3)); and the coarse fraction of PM (HR = 1.05 (95% CI 1.00, 1.10), IQR = 0.9 μg/m(3)). Adjustment for traffic noise only slightly attenuated these associations. The association for a 5 dB increase in road-traffic noise with mortality was HR = 1.02 (95% CI 0.99, 1.06) independent of air pollution.
  
  
  CONCLUSIONS
  These data support a relationship of primary traffic and regional/urban background air pollution with poor prognosis among MI survivors. Although imprecise, traffic noise appeared to have a modest association with prognosis independent of air pollution.
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, UK; MRC-PHE Centre for Environment and Health, King's College London, UK. Electronic address: ctonne@creal.cat.
authors.forename: Cathryn
authors.initials: C
authors.lastname: Tonne
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Jaana I
authors.initials: JI
authors.lastname: Halonen
authors.affiliation: MRC-PHE Centre for Environment and Health, King's College London, UK.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Beevers
authors.affiliation: MRC-PHE Centre for Environment and Health, King's College London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Dajnak
authors.affiliation: UK Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health, Imperial College, London, UK.
authors.forename: John
authors.initials: J
authors.lastname: Gulliver
authors.affiliation: MRC-PHE Centre for Environment and Health, King's College London, UK.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Kelly
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Wilkinson
authors.affiliation: MRC-PHE Centre for Environment and Health, King's College London, UK.
authors.forename: H Ross
authors.initials: HR
authors.lastname: Anderson
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008131:London; D008297:Male; D018986:Motor Vehicles; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality; D009622:Noise / Q000009:adverse effects*; D052638:Particulate Matter / Q000009:adverse effects; D010359:Patient Readmission; D016016:Proportional Hazards Models; D017741:Survivors; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: Cohort; Long-term air pollution; Myocardial infarction; Noise; Traffic