June 24, 2015

expert reaction to effect of road traffic noise on stroke and death

A new study has been published that examines possible effects of long-term exposure to road traffic noise on life expectancy and risk of stroke.

Prof. Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said:

“This carefully conducted study shows that there is a detectable, but very small, excess risk of cardiovascular death amongst people chronically exposed to greater levels of traffic noise.  The investigators tried to take account of other related factors, in particular traffic-generated air pollution, which is already known to significantly increase risk.  Their results suggest that reducing air pollution from traffic is more important for heart health than reducing noise.”

Prof. Francesco Cappuccio, Chair of Cardiovascular Medicine and Epidemiology, University of Warwick, said:

“The present study is a welcome addition to the growing body of evidence to suggest that environment, in its own entirety as well as in its different facets, plays an important role in determining avoidable ill-health. The authors show that long term excessive road traffic noise, even when allowing for the effect of pollution, is associated with a small but significant increased risk of death and hospitalisation in one of the largest urbanised areas of Europe (Greater London), most of which is due to strokes.

“The results do not imply a direct cause-effect relationship. However, they are consistent with other evidence to suggest a possible causal link. For instance, it has been well established that nocturnal traffic noise disrupts sleep quantity and quality. If sustained over time, these disturbances, like sleep deprivation, have been associated with a 12% increased risk of all-cause mortality (1), mainly due to a 15% increase in stroke events (2) and high blood pressure (3). Public health policies must pay more attention to this emerging evidence.”

(1) Cappuccio FP, D’Elia L, Strazzullo P & Miller MA. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep 2010; 33(5): 585-592

(2) Cappuccio FP, Cooper D, D’Elia L, Strazzullo P & Miller MA. Sleep duration predicts cardiovascular outcomes: a systematic review and meta-analysis of prospective studies. Eur Heart J 2011; 32: 1484-92

(3) Cappuccio FP, Stranges S, Kandala N-B, Miller MA, Taggart FM, Kumari M, Ferrie JE, Shipley MJ, Brunner E, Marmot MG. Gender-specific associations of short sleep duration with prevalent and incident hypertension: the Whitehall II Study. Hypertension 2007; 50: 694-701

Dr Tim Chico, Reader in Cardiovascular Medicine / consultant cardiologist, University of Sheffield, said:

“This study finds that people who live in areas of high traffic noise have a slightly higher risk of stroke and death. The risk seems to be about 5% higher compared to living in a low noise area, which is far less than the risk of smoking, being overweight, or not exercising. However, the risk of an individual developing heart disease probably reflects all such influences, big and small.

“This study cannot and does not prove that noise causes cardiovascular disease, although its findings are consistent with other studies showing that noise increases blood pressure, and this could contribute to developing cardiovascular disease. There may be other factors that link high noise areas with cardiovascular disease, and it is difficult to take all of these into account. Nevertheless, given what we know about traffic emissions increasing heart disease, we should remember that travelling by foot or bike is definitely healthier, both for you and for the people around you.”

‘Road traffic noise is associated with increased cardiovascular morbidity and mortality and all-cause mortality in London’ by Jaana I. Halonen et al. published in the European Heart Journal on Wednesday 24 June 2015.

Declared interests

Prof. Francesco Cappuccio and Dr Tim Chico declared no interests.

None others received.