finds no association between cell phone use and auditory tumours
The risk of
acoustic neuroma (a rare and benign tumour of the auditory nerve)
was unrelated to the frequency and duration of cell phone use, according
to a recently published study. Muscat and his colleagues conducted
a case-control study
as part of a larger study on brain tumours (see "Research
- Epidemiology" and "What's
New", January 2001). They interviewed 90 patients with
acoustic neuroma and 86 controls, focusing on handheld cellular
telephone use and lifestyle. The risk of tumours did not increase
with cell phone use and did not vary significantly by the frequency,
duration, and lifetime hours of use. In patients who used cell phones
the tumour occurred more often on the opposite side of the head
from the side on which they used their phone.
recommend that further studies should be conducted on long-term
phone users. More details of this study can be found in "Research
Muscat JE, Malkin MG, Shore RE, Thompson S, et al. Handheld cellular
telephone use and risk of acoustic neuroma. Neurology 2002;58:1304-1306.
study on brain tumours
colleagues from Helsinki have done a study on tumours of the brain
and salivary glands, comparing ownership of cellular phones by tumour
patients and controls. Their results were that "cellular phone
use was not associated with brain tumors or salivary gland cancers
overall, but there was a weak association between gliomas
and analog cellular phones." The latter association was based
on only 26 cases who had owned a cellular phone. The authors also
state that a register-based approach has limited value because of
lack of information on exposure. More details of this study can
be found at "Research - Epidemiology".
A, Hietanen M, Luukkonen R, Koskela R-S. Brain tumors and salivary
gland cancers among cellular telephone users. Epidemiology 2002;13:356-359.
Microwaves fail to promote tumours in rats
Experiments - cancer studies" we review studies that have
looked at the effect of RF radiation on the promotion of tumours.
Another study is now reported that is in agreement with the results
of most other studies, which have shown no effect. Bartsch and colleagues
did three experiments one year apart on rats that were given DMBA
(a known carcinogen) and
then exposed to RF radiation for 24 hours a day for 11 to 12 months.
The radiation was the equivalent of that found 6.3 metres from a
typical base station antenna of 200 W. There was no significant
effect of the radiation on tumour latency (the time it takes for
a tumour to develop) or on tumour incidence. There was a reduction
in latency for the development of the first malignant tumour in
each animal in the first experiment but not in the others. The authors
have some difficulty in explaining this finding, since each experiment
used similar, highly standardized conditions.
details, see "Toxicological
Experiments - cancer studies".
Bartsch H, Bartsch C, Seebald E, Deerburg F, et al. (2002): Chronic
exposure to a GSM-like signal (mobile phone) does not stimulate
the development of DMBA-induced mammary tumors in rats: Results
of three consecutive studies. Radiation Research 157:183-190.
- Or in mice
study also used DMBA, this time painted on the skins of ten-week-old
mice, which were then exposed to 1.5 GHz (TDMA) signal for 90 minutes
per day, 5 days a week, for 19 weeks. Control mice had the DMBA,
but not the EMF, exposure. There were no differences in the incidence
of skin tumours, or of leukaemias
or lymphomas between
the RF-exposed and the control mice.
This study is
also summarized in more detail in " oxicological
Experiments - cancer studies".
Imaida K, Kuzutani K, Wang J, Fujiwara O, et al. Lack of promotion
of 7,12-dimethylbenz(a)anthracene initiated mouse skin carcinogenesis
by 1.5 GHz electromagnetic near fields. Carcinogenesis 2001;11:1837-1841