Research shows link between those living close to a busy road and heart problems

With one of the busiest roads in the country running through the heart of it, Chiswick residents will be concerned to hear that exposure to noise from road traffic can increase the risk of stroke in the over 65s.

According to a report published in The Daily Telegraph, researchers found that for every 10 decibel (dB) increase in noise, the risk of stroke increases by more than a quarter (27%).

Although the study shows a link rather than a cause, NHS experts agree that it seems plausible that noise might increase stroke risk, especially very high levels of noise, via raised blood pressure or lack of sleep or other theoretical mechanisms, this is quite a weak link. As the researchers acknowledge, these differences could be due to unmeasured or incompletely adjusted factors that also increase stroke risk. The researchers point out some other strengths and limitations to their study:

• The findings are made more robust with the adjustment for air pollution, which is known to correlate with road traffic noise, as both air pollution and noise increased the nearer the participants lived to busy roads.

• They acknowledge the link between stroke and socioeconomic status by saying that there was a higher proportion of people on a low income among those exposed to high noise levels. As socioeconomic status has been found to be a predictor for stroke, this potential confounder needs further exploration.

• A potential weakness is that the noise estimates were based on modelled geographic averages and not on measured values.

• The researchers also say that they had information only on residential addresses and not, for example, work or holiday-home addresses. This could have affected the accuracy of the modelled noise levels.


March 1, 2011