LONDON, ENGLAND -- June 19, 1998 -- Radio-frequency electromagnetic fields emitted by mobile telephones cause an increase in blood pressure, report Dr. S. Braune and colleagues from Freiburg, Germany, in this week's issue of The Lancet.

The 10 volunteers studied were all young (26-36 years) and each had a mobile telephone attached to the right-hand side of their heads where a telephone would usually be held. The phones were switched on by remote control at various intervals, but without sound, so that the volunteers did not know when they were being exposed to the electromagnetic fields. The researchers then measured blood pressure while the volunteers were lying down and standing up, along with other measurements of heart function.

Dr. Braune and colleagues recorded increases of five to 10 mmHg in blood pressure while the volunteers were resting and exposed to the switched-on mobile telephone. Such an increase could have adverse effects on people with high blood pressure.

Children who use mobile phones are at risk of memory loss, sleeping disorders and other health problems.

Dr Gerard Hyland of the University of Warwick says that children are particularly vulnerable to low level, non-thermal, radiation because their immune systems are still developing and their skulls are smaller and thinner than adults'.

He explained that the body is an extremely sensitive electrochemical instrument and that the effect of microwaves on the body is a bit like interference on a radio. "It has an impact on the stability of cells in the body. The main effects are neurological, causing headaches, memory loss and sleeping disorders," he said.