Research by German scientists indicates that the electromagnetic fields given off by a phone can raise your blood pressure, even if you do not know the phone is working.
The finding is the third piece of medical evidence in the past year pointing towards malignant effects of such phones, which have spread rapidly in the past 15 years. Previous research showed that phones could increase cancer risk for rats, and cause memory loss and confusion.
The latest study, published today in the Lancet, was carried out by a team at Freiburg University with the German telephone company Deutsche Telekom. A team of 10 healthy people aged between 26 and 36 had phones strapped to the sides of their head. These were turned on and off remotely, so the volunteers did not know if the phones were emitting microwaves or not.
The volunteers' blood pressure, heart rate and estimates of "well-being" were measured over a number of days while their phones were on and off. The researchers found a small but significant rise in blood pressure, though no statistical effect on heart rate.
The research is another piece in a jigsaw that does not seem to favour the phones. Fears that they could trigger cancers first surfaced in the United States in 1993, when a man rang a television talk show and claimed his wife had developed a tumour behind her left ear after using an early model of mobile phone.
The National Radiological Protection Board, the organisation which is responsible for monitoring the health effects of radiation, said it could not comment on the latest research. But it has previously accepted that low-level radiation could alter the way brain cells behave.Reuse content