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Marzo 2001
Danish study
shows no cancer risk
The much-anticipated
study from Denmark (see November 1999 and April 2000 updates) has
now been published. The cancer rates were studied in all cellular
telephone subscribers and compared with expected rates, derived
from the entire Danish population. There were no increased rates
in the telephone users, either for overall cancer, or for specific
cancer types, such as brain cancer or leukaemia. For further details
of this article, see "Research
- Epidemiology".
Robert Park,
in an editorial in the same issue of the journal, comments on public
perception of risk.
This is the
third large epidemiological study on cell phones and cancer to be
published in recent months - see the January and February 2001 updates
for news of the studies by Muscat and Inskip.
References:
Johansen C, Boice JD, McLaughlin JK, Olsen JH. Cellular telephones
and cancer - a nationwide cohort study in Denmark. J Natl Cancer
Inst 2001;93:203-207.
Park
RL. Cellular telephones and cancer: how should science respond?
J Natl Cancer Inst 2001;93:166-167.
Another study on EEGs from Finnish group
In July 2000
we noted that a group of Finnish researchers had reported that RF
radiation could affect the electroencephalogram
(EEG) tracings during performance of an auditory memory task.
These authors
have repeated their study on volunteers performing a visual memory
task. For further details of these articles, see "Research
- Clinical - EEG".
Reference:
Krause CM, Sillanmaki L, Koivisto M, Haggquist A, et al. Effects
of electromagnetic fields emitted by cellular phones on the electroencephalogram
during a visual working memory task. Intl J Rad Biol 2000;76:1659-1667.
Study
shows no genotoxic effect from RF radiation
Claims have
been made from time to time that RF radiation can produce genotoxic
effects on cells - that is, genetic damage in the DNA
that could predispose the cell to cancer formation. A new study
reports that no such effects were seen in human blood cells that
had been exposed to RF radiation at a cellular telephone frequency
(835.62 MHz). The mean SAR was 4.4 or 5.0 W/kg. The paper by Vijayalaxmi
and colleagues includes a useful summary of previous experiments
in this area of research. Another paper by this group is summarised
in the January 2001 "What's New".
Reference:
Vijayalaxmi, Pickard WF, Bisht KS, Leal BZ, et al. Cytogenetic studies
in human blood lymphocytes exposed in vitro to radiofrequency radiation
at a cellular telephone frequency (835.62 MHz, FDMA). Radiat Res
2001;155:113-121.
No
effect from RF radiation on cancer promotion in laboratory study
While there
have been some laboratory studies that have suggested that RF radiation
can induce cancer, "the great majority of these studies have
failed to demonstrate genotoxic effects" (Royal Society of
Canada Expert Panel). Another study, by Roti Roti and colleagues,
has also failed to demonstrate cancer transformation in cells exposed
to RF radiation in the cell phone range. In a further experiment,
the cells were first exposed to X-rays and then to the RF radiation.
The cells showed no difference from controls in the rate of cancer
transformation.
Reference:
Roti Roti JL, Malyapa RS, Bisht KS, Ahern EW, et al. Neoplastic
transformation in C3H 10T1/2 cells after exposure to 835.62 MHz
FDMA and 847.74 MHz CDMA radiations. Radiat Res 2001;155:239-247
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