Being exposed to high levels of airport noise could raise your risk of heart disease, according to two new studies published in the British Medical Journal.
One study, conducted by researchers from Imperial College London and King's College London, looked at the association between aircraft noise and hospital admission and death rates of people living near London's Heathrow airport. It showed that people living in areas exposed to the highest aircraft noise levels had a 10 to 20 percent higher risk of hospital admissions and heart- and stroke-related deaths, compared with people exposed to the lowest levels of aircraft noise.
That research involved analysis of 12 boroughs in London, as well as nine districts outside of London, where aircraft noise was louder than 50 decibels (which is how loud a typical conversation in a room might be). Researchers divided the boroughs up into 12,110 areas (with about 300 people in each area), and examined noise levels in 2001 and compared them with hospital admissions data from 2001 to 2005.
"These findings suggest a possible link between high levels of aircraft noise and risk of heart disease and stroke. The exact role that noise exposure may play in ill health is not well established. However, it is plausible that it might be contributing, for example by raising blood pressure or by disturbing people's sleep," study researcher Dr. Anna Hansell, of the School of Public Health at Imperial College London, said in a statement. "The relative importance of daytime and night-time noise also needs to be investigated further."
The second study was based on U.S. data and conducted by researchers from the Harvard School of Public Health and Boston University School of Public Health. The researchers looked at 2009 heart-related hospital admission data from 6 million Medicare recipients who lived near 89 U.S. airports.
Just like in the first study, researchers found an association between higher levels of noise and increased risk of hospitalization. Specifically, a 10 decibel increase in aircraft noise in a ZIP code was associated with a 3.5 percent increase in the cardiovascular hospitalization rate. And the people living in ZIP codes with the highest airport noise (more than 55 decibels) also had the highest risk of hospitalization. The results held true even after taking into other potential risk factors, such as socioeconomic status, air pollution and proximity to roadways.
"Our results provide evidence of a statistically significant association between exposure to aircraft noise and cardiovascular health, particularly at higher exposure levels," the researchers wrote in the study. "Further research should refine these associations and strengthen causal interpretation by investigating modifying factors at the airport or individual level."
This isn't the first time noise has been linked with heart risks. A study presented at the American Thoracic Society meeting earlier this year showed an association between cardiovascular disease risk and exposure to air pollution and noise pollution. And HealthDay reported on a study in the journal Environmental Health Perspectives showing that even everyday noise could cause heart rate to go up and negatively affect heart rate "variability" (the ability of the heart to adapt to environmental influences).