London, UK (Web Desk): A recent study has revealed that radiation from mobile phones may cause brain tissue damage.
Scientists discovered that emissions from handsets affect the delicate make-up of cells in blood vessels, and could be a health hazard to regular users of the UK's 50million mobile phones.
They stated that the radiations might disable a safety barrier in the body which protects the brain from harmful substances in the blood, they believe.
It is the first time scientists have used cells from human blood vessels rather than rats, bringing researchers closer to the truth about long-term mobile phone use.
Despite the millions spent on research in the last decade, the health implications of sustained use are still unclear.
The biggest British study, led by Sir William Stewart, found two years ago that there was no evidence of a risk to health. A study published last year by the American National Cancer Institute also could not find a link between increased risk of brain cancer and mobile use.
But the latest study by the Radiation and Nuclear Safety Authority in Finland - the home of mobile phone giant Nokia - has found that one hour of mobile radiation triggered potentially harmful changes in human cells.
The radiation made the cells in blood vessel walls shrink - allowing potentially harmful substances in the blood to 'leak' into the brain.
Repeated exposure, the study found, could make the blood-brain barrier more permeable, leading to increased brain damage.
It concluded: 'Repeated occurrences of these events on a daily basis, over a long period of time, could become a health hazard due to possible accumulation of brain tissue damage.'
Professor Dariusz Leszczynski, who led the study, said: 'There is massive use of mobile phones in society now; our brains are being bombarded with radiation all the time.
'We really don't know what the impact is going to be on people regularly using a mobile phone for ten or 20 years. That is why more studies are urgently needed.'
Mobile phone radiation may also contribute to the growth of tumours caused by other factors, he said.
He is due to present the findings at a conference in Quebec City on Monday. They were published in the German scientific journal Differentiation.
In January, a new £ 7.4million UK research programme was announced, backed by the Government and the mobile phone industry, to be managed by an international committee of experts led by Sir William.
The programme includes 15 studies which will seek clear conclusions about the health hazards of mobile phones, in particular fears of an association-between radiation and brain cancer.
Sir William blasted mobile firms earlier this year for selling phones to children, because their skulls are thinner and more at risk from the effects of radiation.
The skull of a five-year-old, for example, is as thin as half a millimetre at the ear, whereas the skull of a 21-year-old is about two millimetres.
Fears over the safety of mobile phones are soon to be tested in court in the U.S. where lawsuits filed against Vodafone have alleged personal injury, including brain cancer.
Vodafone revealed in its annual report yesterday that it is named in four lawsuits - but would be 'vigorously defending' the claims.
Meanwhile, the Consumers' Association said there was still insufficient evidence to say whether mobiles are safe.
A spokesman said: 'At the moment, it's too soon to reach a definitive verdict on health risks from mobile phones, but neither has research given it the all clear.'