Using a mobile phone before going to bed could stop you getting a decent night"s sleep, research suggests. The study, funded by mobile phone companies, suggests radiation from the handset can cause insomnia, headaches and confusion. It may also cut our amount of deep sleep - interfering with the body"s ability to refresh itself. The study was carried out by Sweden"s Karolinska Institute and Wayne State University in the US. Funded by the Mobile Manufacturers Forum, the scientists studied 35 men and 36 women aged between 18 and 45. Some were exposed to radiation equivalent to that received when using a mobile phone, others were placed in the same conditions, but given only "sham" exposure. Those exposed to radiation took longer to enter the first of the deeper stages of sleep, and spent less time in the deepest one.
The scientists concluded: "The study indicates that during laboratory exposure to 884 MHz wireless signals components of sleep believed to be important for recovery from daily wear and tear are adversely affected." Researcher Professor Bengt Arnetz said: "The study strongly suggests that mobile phone use is associated with specific changes in the areas of the brain responsible for activating and coordinating the stress system." Another theory is that radiation may disrupt production of the hormone melatonin, which controls the body"s internal rhythms.