Studies from both sides of the pond show that people exposed to high levels of aircraft noise are at a higher risk of cardiovascular disease, according to the BMJ.
Previous research has shown that people living near airports experience physiological and psychological reactions to the high noise levels. These include disturbed sleep patterns, nervousness, annoyance and higher blood pressure.
But the extent to which aircraft noise influences the risk of adverse health outcomes had not been well-studied - until now.
According to the National Air Traffic Controllers Association, there are more than 87,000 flights crossing the US every day. And they all have to take off and land somewhere.
Researchers from Boston, MA, used a multi-airport retrospective study of approximately 6 million older people (aged 65 and over) living near 89 airports, while researchers from London focused on Heathrow Airport and the 3.6 million people who live nearby.
Two studies found a link between aircraft noise exposure and increased CVD risks, with one finding a link between aircraft noise and increased stroke risk.
In the Boston study, researchers from the Harvard School of Public Health and Boston University's School of Public Health analzyed data from the national medical insurance program (Medicare) and superimposed contours of aircraft noise levels provided by the US Federal Aviation Administration over the 2,218 zip codes surrounding the airports.
To help standardize the results, all the participants in the study lived within the 45 decibel (dB) contour of the airports.
But even after the figures had been adjusted for other factors, including socioeconomic status, demographics, air pollution and proximity to any major roads, they found that, on average, zip codes with 10 dB higher aircraft noise experienced a 3.5% higher hospital admission rate for cardiovascular disease.
And participants exposed to the highest noise levels - more than 55 dB - experienced the highest number of hospital admissions for cardiovascular disease.
"Our results provide evidence of a statistically significant association between exposure to aircraft noise and cardiovascular health, particularly at higher exposure levels. Further research should refine these associations and strengthen causal interpretation by investigating modifying factors at the airport or individual level."
Heathrow airport is one of the busiest airports in the world and is situated in a densely populated area of west London. The research focused on 12 London boroughs and nine districts, all of which were in the 50 dB noise contour, as defined by the Civil Aviation Authority (CAA).
Researchers compared the post codes for people living within their designated study area with hospital admissions, using data from the Office for National Statistics and the Department of Health.
Taking into account other factors that could influence the results, such as social depravation, air pollution and road traffic noise, the researchers concluded that high levels of aircraft noise are also associated with an increased risk of stroke, coronary heart disease and cardiovascular disease.
While the link between aircraft noise and stroke is new, it does fit with the link between noise and high blood pressure.
Two studies, one conclusion
Taking both studies into account, the results suggest that aircraft noise does have a direct impact on people's health.
Researchers from both teams agree that further work is needed to understand the possible health implications associated with aircraft noise, and they are particularly interested in clarifying the relative importance of nighttime noise, as compared with daytime noise.
Researchers from the Heathrow study point out the importance of the study when expanding or building airports:
"How best to meet commercial aircraft capacity for London and other major cities is a matter of active debate, as this may provide major economic benefits. However, policy decisions need to take account of potential health related concerns, including possible effects of environmental noise on cardiovascular health."
Stephen Stansfeld, professor of psychiatryat Wolfson Institute of Preventive Medicine writes in the BMJ:
"These studies provide 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."
"The results imply that the siting of airports and consequent exposure to aircraft noise may have direct effects on the health of the surrounding population. Planners need to take this into account when expanding airports in heavily populated areas or planning new airports."