SOURCE: London School of Hygiene & Tropical Medicine, news release, June 23, 2015
TUESDAY, June 23, 2015 (HealthDay News) -- Long-term exposure to noise pollution from traffic may reduce life expectancy, a new study contends.
Living near busy roads may also increase the risk of stroke, particularly among older people, the researchers said.
"Road traffic noise has previously been associated with sleep problems and increased blood pressure, but our study is the first in the U.K. [United Kingdom] to show a link with deaths and strokes," study author Jaana Halonen, from the London School of Hygiene & Tropical Medicine, said in a university news release.
But, it's important to note that the study only showed an association between road noise and these health outcomes, and not a cause-and-effect relationship.
"From this type of study, we can't tell for certain what the risks of noise are to an individual, but these are likely to be small in comparison with known risk factors for circulatory diseases like diet, smoking, lack of exercise and medical conditions such as raised blood pressure and diabetes," study co-author Dr. Anna Hansell, from the MRC-PHE Centre for Environment & Health at Imperial College London, said in the news release.
"However, our study does raise important questions about the potential health effects of noise in our cities that need further investigation," she added.
The findings were published June 23 in the European Heart Journal.
The study looked at information from 8.6 million people living in London between 2003 and 2010. During this time, almost 450,000 adults died. About 290,000 of those adults were elderly. Just over 400,000 adults were admitted to the hospital for heart problems during the same time period. About 180,000 of these people were elderly, the study reported.
Researchers measured how much traffic noise these people were exposed to, day and night. They also looked at other risk factors, such as the participants' age, sex and neighborhood characteristics, including smoking rates and air pollution.
Deaths were 4 percent more common in areas with daytime road traffic noise of more than 60 decibels (dB) compared to areas with noise levels less than 55 dB.
The World Health Organization says community noise levels above 55 dB are potentially harmful. As many as 1.6 million people in London live in areas with daytime traffic noise levels above 55 dB, the researchers noted.
The study authors suggested that chronic noise levels may cause troubling sleeping and stress, which might contribute to high blood pressure and heart disease.
Adults living in areas with the most daytime noise pollution were also 5 percent more likely to be treated for a stroke in the hospital than those living in areas with less noise. The risk of stroke was even higher for elderly people living in the noisiest daytime areas. These residents were 9 percent more likely to have a stroke. Elderly people exposed to noise pollution at night had a 5 percent higher stroke risk, the study said.
These findings add to a growing body of evidence that reductions in noise pollution could have health benefits, the researchers concluded.
The U.S. Environmental Protection Agency provides more information on noise pollution.