Using a mobile phone before going to bed
could stop you getting a decent night's sleep, research
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
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
Another theory is that radiation may
disrupt production of the hormone melatonin, which controls
the body's internal rhythms.
About half the people in the study believed
themselves to be "electrosensitive", reporting symptoms
such as headaches and impaired cognitive function from
mobile phone use.
But they proved to be unable to tell
if they had been exposed to the radiation in the test.
Alasdair Philips is director of Powerwatch,
which researches the effects of electromagnetic fields
He said: "The evidence is getting stronger
that we should treat these things in a precautionary way.
"This research suggests that if you need
to make a phone call in the evening it is much better
to use a land line, and don't have your mobile by your
Mike Dolan, executive director of the
Mobile Operators Association, said the study was inconsistent
with other research.
He said: "It is really one small piece
in a very large scientific jigsaw. It is a very small
effect, one researcher likened it to less than the effect
you would see from a cup of coffee."
Last September a major six-year study
by the UK Mobile Telecommunications and Health Research
Programme (MTHRP) concluded that mobile phone use posed
no short-term risk to the brain.
However, the researchers said they could
not rule out the possibility that long-term use may raise
the risk of cancer.
In the UK, mobile services operate within
the frequency ranges 872 to 960 MHz, 1710 to 1875 MHz
and 1920 to 2170 MHz.