Research shows that the chance of developing a malignant brain tumour could be eight times higher in the countryside compared with towns. And the risk of developing any brain tumour rises fourfold for country-dwellers using mobile phones for five years or more, says a study published today.
It is thought the extra risk may be triggered by the higher power output from phones used in rural areas. Base stations tend to be further apart outside towns, which means the phone needs to generate higher radiowave intensity to compensate for the poor signal.
This could result in higher exposure to radiation emissions. Experts say there are no proven health risks in using mobile phones, but they are such a new phenomenon that problems could still emerge. There are 60m mobile users in Britain - up from 9m in 1998 - with around one quarter aged under 18.
In the latest study from Sweden, researchers looked at more than 1,400 adults aged 20 to 80 who had been diagnosed with a malignant or benign brain tumour between 1997 and 2000. The brain cancer patients were compared with a similar number of healthy adults living in the same area. Each group was asked to recall their daily use of mobile and cordless phones, according to a report in the journal of Occupational and Environmental Medicine.
The researchers at University Hospital in Orebro found there was a higher risk of all types of tumours for people living in rural areas - defined as fewer than 90,000 inhabitants - compared with towns. People living in a rural area who had been using a digital mobile phone for more than three years were more than three times more likely to be diagnosed with a brain tumour than those living in urban areas.
There was a fourfold higher risk for those using a digital mobile phone for five or more years in the countryside compared with towns. An eightfold increase in malignant brain tumours was found in country dwellers compared to those in towns. Researchers said the length of time users spent on the phone had little impact on the chances of being diagnosed with a brain tumour.
Professor Lennart Hardell, who led the research, said the findings should be treated with caution because the actual number of brain tumours in areas classified as rural was very small. 'Clearly our results support the notion that exposure may differ between geographical areas,' he added. 'But there is no information on the exact difference between geographical areas.'
There are 45,000 base stations fitted with antenna or 'masts' situated 200 metres-500 metres apart in towns and up to 5 kilometres apart in rural areas of the UK. Alasdair Philips, director of the mobile phone emission pressure group Powerwatch, said: 'It would be sensible for those in areas with a poor signal to limit their calls.'
Mike Dolan, executive director of the Mobile Operators Association, said: 'All mobile handsets in the UK comply with international health and safety guidelines which apply whether the phones are used in rural or urban areas. Individual studies must be seen in the light of the total research effort into mobile phone safety.'