A study from Austria shows that people who used their mobiles for an average of 10 minutes a day were 71 percent more likely to have tinnitus than other people. The study also found that those who used a cell for four or more years were twice as likely to have chronic ringing in the ears as those in the control group.
Researchers at the Institute for Environmental Health at the University of Vienna, Austria, compared 100 patients needing treatment for chronic tinnitus with 100 random participants who didn't have the disorder but were of similar age and gender. The two groups were tracked for a full year. Patients with impaired hearing due to noise, high blood pressure or another ear-related illness weren't included, nor were those taking medication that causes ringing or hissing in the ears.
Subjects were questioned about what kind of phone they used and where, the length of time and frequency of the calls, the ear they usually held the phone to and the use of hands-free devices.
Mainly on one side
Patients who had regularly talked on a mobile phone before the tinnitus started were 37 percent more likely to have it than those in the control group, the findings indicated. People who were on their cell phones for an average of 10 minutes a day had a 71 percent greater chance of suffering from the condition.
Those who used a cell for four or more years were twice as likely to have chronic ringing in the ears as those in the control group, according to the study. The majority of the tinnitus was on only one side, with about 40 patients describing it as distressing "most of the time."
"It is unlikely that the increased risk of tinnitus from prolonged mobile phone use obtained in this study is spurious," wrote lead author Hans-Peter Hutter and colleagues.
A widespread problem
It is thought about 10 - 15 % of the world's population have some form of tinnitus.
Because of the widespread use of the cell phones, even a slightly increased risk of tinnitus would be of "public health importance", the authors wrote, particularly given that the condition can in some cases profoundly interfere with daily life.
The high radio frequency emitted from mobile phones is thought to be a cause of the hearing problems, though there is no conclusive data proving the theory. The Researchers said that a possible explanation for their findings could be that the auditory pathway directly absorbs a significant amount of microwave energy emitted by a cell phone.
The study was published in Occupational & Environmental Medicine, July 2010.
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