Living in neighbourhoods with high levels of aircraft noise is associated with a higher risk of cardiovascular disease, U.S. and British research suggests.

Two studies published in Wednesday's British Medical Journal offered "preliminary evidence that aircraft noise exposure is not just a cause of annoyance, sleep disturbance and reduced quality of life but may also increase morbidity and mortality from cardiovascular disease," an accompanying editorial said.

In one study, Francesca Dominici's team at Harvard School of Public Health in Boston found a higher rate of admission to hospital with cardiovascular problems among people aged 65 and older living near 89 airports in the U.S. in 2009.

On average, zip codes with 10 decibel higher aircraft noise had a 3.5 per cent higher cardiovascular hospital admission rate. The association remained after taking socioeconomic status, demographic factors, air pollution proximity to roadways into account in the analysis.

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The association between hospitalization for cardiovascular disease and noise was strongest for those exposed to the most noise. (Kirsty Wigglesworth/Associated Press)

The association was strongest for those exposed to the most noise.

In total, an estimated two per cent of hospitalizations for cardiovascular disease in the study subjects were attributable to aircraft noise.

City and town planners "need to take this into account when extending airports in heavily populated areas or planning new airports," Stephen Stansfeld, a professor at Queen Mary University of London who was not part of either research team, wrote in a journal commentary.

Hugh Davies is an associate professor in the school of population and public health at the University of British Columbia, where he studies the non-auditory health effects of noise. 

"We would expect to find the same results around comparable Canadian airports," Davies said of the Harvard research. 

"I think the evidence linking noise and heart disease is sufficient enough to warrant it being considered in any health impact assessments of new airport development," he added in an email.

Davies said the EU has responded to evidence of the role of noise in heart disease, sleep disturbance and stress with a risk-reduction strategy.

A second study looked at about 3.6 million residents living near London's Heathrow airport, one of the world's busiest airports.

As in the U.S. study, researchers obtained levels of aircraft noise from aviation authorities.

"We identified significant excess risks of stroke, coronary heart disease, and cardiovascular disease, especially among the two per cent of the population affected by the highest levels of daytime and nighttime aircraft noise," Anna Hansell from Imperial College London and her co-authors concluded.

Some factors that could have affected the results, such as age, sex, ethnicity, social deprivation, smoking, air pollution, and road traffic noise, were also considered.

Questions that remain to be answered include whether noise at night or in the day is more important and if there are safe levels of exposure, Davies said.

The U.S. study was funded by the Federal Aviation Administration. The British study was funded by Public Health England.

With files from Reuters