COPENHAGEN, Denmark, Jan. 28 (UPI) -- Danish researchers say exposure to traffic noise increases the risk of stroke, especially among people age 65 and older.

Study leader Dr. Mette Sorensen of the Institute of Cancer Epidemiology, Danish Cancer Society in Copenhagen, Denmark, says the researchers found that for every 10 decibels added to noise level, the risk of having a stroke increased by 14 percent.

The study, published online in the European Heart Journal, found people age 65 and under had no statistically significant increased risk of stroke. However, among those 65 and older, the risk increased by 27 percent for every 10 decibels of higher road traffic noise. For older people, researchers found indications of a threshold limit at approximately 60 decibels -- above which the risk for stroke seemed to increase even more.

"These studies highlight the need for action to reduce people's exposure to noise," Sorensen said in a statement. "If we assume that our findings represent the true risk, and the association between traffic noise and stroke is causal, then an estimated 8 percent of all stroke cases and 19 percent of cases in those age 65 and older could be attributed to road traffic noise."

Sorensen and colleagues studied medical and residential histories for 51,485 participants, ages 50-64, in the Copenhagen and Aarhus areas for 10 years. A total of 1,881 suffered a stroke during the study period.