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

Cathryn Tonne,Sean D Beevers,Frank J Kelly,Paul Wilkinson,Jaana I Halonen,H Ross Anderson,David Dajnak,John Gulliver

doi:10.1016/j.ijheh.2015.09.003

Abstract

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. 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. 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. 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.

Highlights

The coefficient of variation was greater for primary traffic pollutants compared to pollutants representing regional and urban background
There was no indication that primary traffic pollutants were more strongly associated with prognosis compared to regional or urban background pollutants
Traffic noise was only moderately correlated with air pollution and did not fully explain the observed associations with air pollution

Summary

Introduction

Health effects of long-term exposure to air pollution have been primarily examined among general populations (Beelen et al, 2014; Hoek et al, 2013; Carey et al, 2013; Cesaroni et al, 2014).studies among susceptible sub-groups, such as survivors of myocardial infarction (MI), are scarcer and results have included positive as well as null findings (Zanobetti and Schwartz, 2007; von Klot et al, 2009; Koton et al, 2013; Tonne and Wilkinson, 2013; Rosenlund et al, 2008). Health effects of long-term exposure to air pollution have been primarily examined among general populations (Beelen et al, 2014; Hoek et al, 2013; Carey et al, 2013; Cesaroni et al, 2014). In contrast to air pollution, individual-level estimates of road traffic noise in relation to all-cause mortality are not currently available in general populations or among MI survivors. 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. Traffic noise appeared to have a modest association with prognosis independent of air pollution

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