A small study published today suggests that using a mobile for at least four years seems to be linked to a doubling in the risk of developing chronic tinnitus, a persistent ringing or hissing in the ear.
Regular use is defined as 10 minutes per day by the researchers, from the Institute of Environmental Health atthe University of Vienna.Chronic tinnitus is becoming more common and affects around 10 to 15 per cent of people in the developed world; there are few treatment options.
While there are some known causes or triggers, such as head trauma or ear disorders, there are few known risk factors or clear explanations for the increasing prevalence.The authors compared 100 patients who needed treatment for chronic tinnitus with 100 people, matched for sex and age and who did not have the disorder, over the period of a year.All were asked about the type of phone they used and where, which was seen as relevant because mobile phone output tends to be stronger in rural areas.They were also asked about how long their calls took, how intensely they used the phone, which ear they preferred and whether they used hand-held devices.Most tinnitus was one-sided with the left side accounting for 38 cases. More than a third described it as distressing “most of the time” which almost a third also had vertigo.Although almost all the participants were mobile users, but only 84 tinnitus patients were using a mobile when the symptoms appeared (compared to 78 in the comparison group at the start of the study).The patients who had used a mobile before the onset of tinnitus were 37 per cent more likely to have the condition than those in the comparison group, while those who used their mobiles for an average of 10 minutes per day were 71 per cent more likely to have the condition.Most people use their phones on both ears and those who had used one for four years or more were twice as likely to have tinnitus compared with those in the comparison group.There are limitations with the study – including the small number of patients included and people’s likelihood of over or underestimating their mobile phone usage. But the authors say: “Considering all potential biases and con founders, it is unlikely that the increased use of tinnitus from prolonged mobile phone use obtained in this study is spurious.“Because of the high prevalence of tinnitus and the widespread use of mobile phones, even a slightly increased risk would be of public health importance.”They suggest that the microwave energy emitted by mobiles and absorbed by the cochlea and auditory pathway may be to blame.The study, published online in the journal Occupational and Environmental Medicine, comes shortly after a warning that children should reduce their mobile phone use where possible. The chief medical officer of Wales, Dr Tony Jewell, put out advice to children which suggested keeping calls short and texting rather than phoning, although it acknowledges that “at the moment it seems that using a mobile phone won’t cause health problems”.