Copenhagen, June 23 (QNA) - Traffic noise may increase the risk of a stroke, a Danish study has found.
The noisiest roads are linked to the highest risk of having a stroke among the middle-aged and older people.
Researchers say there is a low risk to young people, but road noise could account for one in five strokes among pensioners.
The first study to investigate the link found that for every ten decibels more noise, the risk of a stroke increased by 14 per cent. The risk increased by 27 per cent for those aged 65 and over.
When the noise gets above 60dB, the risk of stroke goes higher still, according to a report in the European Heart Journal.
The Danish study investigated 51,485 volunteers aged between 50 and 64 for around ten years. A total of 1,881 had a stroke.
The participants were estimated to be exposed to noise levels between 40dB and 82dB.
In a major city, typical noise levels can average 50-55dB compared with 60-70 for residents living near an airport.
Researcher Dr. Mette Sorensen said the strokes were probably caused by noise disturbing sleep, which in turn raised stress hormones and blood pressure. (QNA)