(CBS News) Living in an area with lots of traffic noise may do more than give you a headache. A new study from Denmark suggests exposure to too much traffic noise may raise a person's heart attack risk.
For the study, researchers looked at more than 57,000 Danes who have been part of a long-running population study of cancer that enrolled participants between the ages of 50 and 64 from 1993 to 1997, and tracked them for an average of ten years.
Of the study pool, 1,600 people suffered their first ever myocardial infarction (MI) - or heart attack - between study enrollment and the follow-up period ending in 2006. Using address information, the researchers estimated the participants' exposure to traffic noise and air pollution over a more than 20-year period. The researchers determined participants were exposed from anywhere from 42 decibels of traffic noise - considered ambient noise - to 84 decibels. Repeated exposure to sounds at or above 85 decibels can cause hearing loss.
The researchers found that for every 10 decibels of added traffic noise near a participant's residence, heart attack risk jumped up 12 percent. The study is published in the June 20 issue of PLoS One.
Previous research suggests air pollution from living near lots of traffic could raise heart attack risk. HealthPop reported last September on a large study that found high levels of car exhaust could significantly raise heart attack risk within only six hours.
The researchers, led by Dr. Mette Sorenson of the Danish Cancer Society, however wrote that for this study air pollution wasn't a factor.
"We found that exposure to road traffic noise was significantly associated with risk for MI both before and after adjustment by air pollution, suggesting an independent effect of road traffic noise."
The exact cause for this association is unknown, but may have to do with sleep disturbances, they wrote, which become more likely with age and especially affect the elderly.
Sorenson told MyHealthNewsDaily one of the dangers with noise pollution is mpost people don't realize they are experiencing it.
"You might wake up thinking that you had a quiet night, but when you look at it in a lab, you see that your sleep stages have been disturbed," she said.
She suggested sleeping in a room with less exposure to traffic noise or insulating the house.