Long-term traffic air and noise pollution in relation to mortality and hospital readmission among myocardial infarction survivors

Int J Hyg Environ Health. 2016 Jan;219(1):72-8. doi: 10.1016/j.ijheh.2015.09.003. Epub 2015 Sep 21.


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.

Keywords: Cohort; Long-term air pollution; Myocardial infarction; Noise; Traffic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / adverse effects
  • Air Pollution / adverse effects*
  • Environmental Exposure / adverse effects*
  • Female
  • Humans
  • London
  • Male
  • Motor Vehicles*
  • Myocardial Infarction* / complications
  • Myocardial Infarction* / mortality
  • Noise / adverse effects*
  • Particulate Matter / adverse effects
  • Patient Readmission*
  • Proportional Hazards Models
  • Survivors
  • Vehicle Emissions*


  • Air Pollutants
  • Particulate Matter
  • Vehicle Emissions