Cell phone masts are harmless - say researchers
phone masts (towers) do not cause harmful short-term health effects,
according to a study of people who say they experience symptoms when
they are close to them. The study runs counter to the notion that
low-level electromagnetic fields from cell phones or their base stations
The British researchers looked at 2G and 3G phone masts in a
laboratory setting where both the participants and researchers did not
know whether the equipment was turned on.
The set-up was designed to mimic (imitate) the output from a phone
mast at 20 to 30 metres from the
"It looks like there was pretty good evidence that people couldn't
detect the signals", said Elaine Fox at Essex University who led the
study. It was published in the journal Environmental Health
Of the 159 people who participated in the experiment, 44 said they
were sensitive to electronic equipment. At first they were told when the
electric field was turned on while being tested. Under these conditions,
the electro-sensitive participants reported symptoms such as headaches
and nausea (sick feeling).
In three further tests, researchers subjected them to 2G radiation,
3G radiation or no radiation under "double blind" conditions, meaning no
one involved knew whether the equipment was switched on.
Under these conditions, two of the electro-sensitive group and five
of the control group correctly identified whether the electricity was on
every time - no better than you would expect by chance alone.
The team measured heart rate, blood volume pulse and sweatiness of
the skin. All of these should go up when the participants experience
unpleasant symptoms or anxiety.
The electro-sensitive individuals had generally higher scores than
the control group for all three, but they did not change when the 2G or
3G radiation was switched on. Anti-phone mast campaigners said the
results were skewed (twisted) since 12 volunteers who claimed to be
sensitive to electronic equipment had dropped out.
"Even a child can see that by eliminating 12 of the original 56
electro-sensitive volunteers ... the study integrity has been completely
breached(affected)," the group Mast Sanity said. It argues these people
were presumably the ones most sensitive to the radiation.
Professor Fox counters that her team was still able to test 44 people
and of the dropouts, none was able to identify correctly when the
radiation was on or off in the first double blind test.
The reduced numbers do mean the statistical power of the experiment
was compromised, though. Prof. Fox estimates there is a 30 per cent
chance that the experiment missed a real effect because of the smaller
numbers. Some anti-mast campaigners are impressed. "The Essex team have
carried out one of the best-designed and executed studies to date", the
group Powerwatch said.
Prof. Fox said scientists should now concentrate on finding the real
cause of the symptoms. "If people are convinced they are suffering
because of mobile phone masts they don't investigate other causes".