
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 expo-
sures 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:
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 asso-
ciation 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 expo-
sure. An ongoing study of brain cancers by the National Cancer