Wednesday, 9 October 2013

Does aircraft noise raise the risk of heart disease?

Scientists have found a possible link between the noise from living directly under an airport flight path and increased risk of strokes and heart disease.

A study published in the British Medical Journal has found a 10 to 20% higher risk among those most exposed to the highest levels of noise around Heathrow airport

The study by researchers at Imperial College and King's College, London, found the biggest increased risk in those exposed to noise levels above 50 decibels  both at day and night - about the volume of a normal conversation in a quiet room.

The researchers at the UK Small Area Health Statistics Unit looked at 12 London boroughs covering 3.6 million people living in 12,000 neighbourhoods and compared noise exposure with deaths and hospital admissions.

The highest risk was among the 2% or 7,000 people exposed to daytime aircraft noise up to 63 decibels.

The researchers stress that they haven't found enough evidence to say that aircraft noise actually causes stroke, heart disease or cardio-vascular disease.

And while 20% may sound high it is dwarfed by the two to three times increased risk from such things as smoking, obesity, bad diet, diabetes and lack of exercise.

The stats on noise come from 2001 and better plane design and routing has cut noise since then - although many living in west London might not notice much difference.

That said, it is one of the first studies to show a possible link between the noise of planes landing and taking off, and increased risk of heart problems and strokes.

Dr Anna Hansell, lead author of the study,, said: "These findings suggest a possible link between high levels of aircraft noise and risk of heart disease and stroke.

“We have increasing level of increasing risk with increasing levels of aircraft noise.”

It is known that heart rates and blood pressure can increase when people are exposed to sudden loud noise. Noise can raise anxiety and night-time flights disturb sleep.

Factors such as the ethnic background of those living closest to the runways, air pollution and road traffic noise were taken into account but at the moment any link between plane noise and heart health is only a suggestion.

One problem is that they only looked at areas, not individuals. And they could not measure the individual exposure to noise in each area.

Nevertheless the findings are interesting - not least to the debate on where to expand London airports - if they need to be expanded at all.

"Our study raises the possibility that aircraft noise could be a contributing factor to stroke, heart disease and cardio vascular disease. But the precise role that noise, including aircraft noise, might play in that isn’t fully understood, Dr Hansell added.

A study in America looked at 89 airports and also found a link between noise and health.

Other scientists praised the studies but warned on their limitations.

Professor Ken McConway, professor of Applied Statistics, at the Open University, said: "Because of the kind of data the researchers used, the studies can't do more than suggest very strongly that we find out much more about aircraft noise and circulatory disease, using different kinds of study that could come much closer to sorting out what causes what. The researchers make these limitations clear in their reports."

No comments:

Post a Comment