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Concerns have been raised about whether cell phone
use can be linked to the development of brain tumors. Now, a study from
Swedish researchers provides evidence backing the claim.
Researchers at the Karolinska Institute in Stockholm,
Sweden, based their findings on questionnaire and interview data obtained
from 209 persons with brain tumors and 425 healthy control subjects. In
a 2-year study, the team found an increased risk in anatomical areas of
the brain exposed to microwaves during a mobile phone call. This risk
holds even when statistical adjustments are made for other risk factors
including ionizing radiation and laboratory exposures.
The researcher pointed out, however, that most of
the people in the study used the older analog system, which gives two
to three times higher exposure than the digital system, which is now mostly
used -- at least in Europe. Larger studies are necessary to make firm conclusions.
The investigators have a much larger brain tumor study ongoing with about
1,500 incident patients and 1,500 controls and the results are expected
within one year.
In light of their current findings, the authors offer
several suggestions about cell phone usage. Use an earpiece to reduce
exposure to the brain and, in a car, use an external fixed antenna. Otherwise,
your exposure to microwaves might even be higher than using the phone
outside the car. In addition, extended conversations should be conducted
on a regular corded telephone.
Insofar as children are concerned, since the developing
brain might be more sensitive to microwaves, children's exposure should
be limited. One useful tip is to find out the specific absorption rate
(SAR) value of various cell phone types. The SAR may differ by as much
as a factor of 20 between different brands.
Original
Study Medscape
General Medicine, May 4, 2000
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