There are over 4,000 new cases of brain tumours per year of
which glioma is the most common type. Early symptoms include
headaches and feelings of nausea; but the causes of these tumours
are currently unknown. Fears have been expressed that mobile phone
use might be a factor.
The four year study by the Universities of Leeds, Nottingham and
Manchester and the Institute of Cancer Research, London found those
who had regularly used a mobile phone were not at a greater overall
risk of developing this type of tumour.
There was no relationship for risk of glioma and time since
first use of a mobile phone, lifetime years of use and cumulative
number of calls and hours of use. Risk was not associated with
phone use in rural areas which was found to be associated with an
increased risk in an earlier Swedish study.
A significantly increased risk was found for tumours which
developed on the same side of the head as the phone was reported to
have been held; but this was mirrored by a decrease in the risk on
the opposite side of the head making it difficult to interpret as a
real effect.
This finding may be due to people with glioma brain tumours
linking mobile phone use to the side of the tumour and therefore
over reporting the use of a phone on the same side as their tumour.
This results in under reporting use on the opposite side of the
head, say the authors.
Mobile phones have been available in the UK since 1985, but
widespread use did not begin until the late 1990s making the number
of long term users (over 10 years) quite small. This study had
limited numbers for estimating the risk of using a phone over a
long period.
Early mobile phones were designed to use analogue signals and
emitted higher power than current digital phones but the study
showed no increased risk of glioma brain tumours with the use of
analogue phones.
