Ericsson R300D User Manual page 13

head during normal telephone conversation. These types of mobile
phones are of concern because of the 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
7
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:
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.
1
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
Guidelines for Safe and Efficient Use