Samsung STH-N275 User Manual page 58

short distance between the phone's antenna-the primary
source of the RF-and the person's head. The exposure to RF
from mobile phones in which the antenna is located at
greater distances from the user(on the outside of a car, for
example) is drastically lower than that from hand-held
phones, because a person's RF exposure decreases rapidly
with distance from the source. The safety of so-called
"cordless phones," which have a base unit connected to
the telephone wiring in a house and which operate at far
lower power levels and frequencies, has not been
questioned.
How much evidence is there that hand-held
mobile phones might be harmful?
Briefly, there is not enough evidence to know for sure,
either way; however, research efforts are on-going. The
existing scientific evidence is conflicting and many of the
studies that have been done to date have suffered from
flaws in their research methods. Animal experiments
investigating the effects of RF exposures characteristic of
mobile phones have yielded conflicting results. A few
animal studies, however, have suggested that low levels of
RF could accelerate the development of cancer in
laboratory animals. In one study, mice genetically altered to
be predisposed to developing one type of cancer developed
more than twice as many such cancers when they were
exposed to RF energy compared to controls. There is much
uncertainty among scientists about whether results
obtained from animal studies apply to the use of mobile
phones. First, it is uncertain how to apply the results
obtained in rats and mice to humans. Second, many of the
studies that showed increased tumor development used
animals that had already been treated with cancer-causing
chemicals, and other studies exposed the animals to the RF
virtually continuously-up to 22 hours per day.
For the past five years in the United States, the mobile
phone industry has supported research into the safety of
mobile phones. This research has resulted in two findings
in particular that merit additional study:
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1. In a hospital-based, case-control study, researchers looked
for an association between mobile phone use and either
glioma (a type of brain cancer) or acoustic neuroma (a
benign tumor of the nerve sheath). No statistically
significant association was found between mobile phone
use and acoustic neuroma. There was also no association
between mobile phone use and gliomas when all types of
types of gliomas were considered together. It should be
noted that the average length of mobile phone exposure in
this study was less than three years.
When 20 types of glioma were considered separately,
however, an association was found between mobile phone
use and one rare type of glioma, neuroepithelliomatous
tumors. It is possible with multiple comparisons of the
same sample that this association occurred by chance.
Moreover, the risk did not increase with how often the
mobile phone was used, or the length of the calls. In fact,
the risk actually decreased with cumulative hours of
mobile phone use. Most cancer causing agents increase
risk with increased exposure. An ongoing study of brain
cancers by the National Cancer Institute is expected to
bear on the accuracy and repeatability of these results.
2. Researchers conducted a large battery of laboratory tests
to assess the effects of exposure to mobile phone RF on
genetic material. These included tests for several kinds of
abnormalities, including mutations, chromosomal
aberrations, DNA strand breaks, and structural changes in
the genetic material of blood cells called lymphocytes.
None of the tests showed any effect of the RF except for
the micronucleus assay, which detects structural effects on
the genetic material. The cells in this assay showed
changes after exposure to simulated cell phone radiation,
but only after 24 hours of exposure. It is possible that
exposing the test cells to radiation for this long resulted in
heating. Since this assay is known to be sensitive to
heating, heat alone could have caused the abnormalities to
occur. The data already in the literature on the response of
the micronucleus assay to RF are conflicting. Thus, follow-
up research is necessary. 2
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