Siemens S46 User Manual page 99

6.11.01 S46 US DRAFT A31008-H5450-A5-*
U.S. FDA
98
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 ac-
celerate the development of cancer in laboratory animals. In one study, mice
genetically altered to be predisposed to developing one type of cancer devel-
oped 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 mo-
bile phones. First, it is uncertain how to apply the results obtained in rats and
mice to humans. Second, many of the studies showed increased tumor de-
velopment used animals that had already been treated with cancer-causing
chemicals, and other studies exposed the animals to the RF virtually continu-
ously - 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 re-
sulted in two findings in particular that merit additional study:
1. In a hospital-based, case-control study, researchers looked for an associa-
tion between mobile phone use and either glioma (a type of brain cancer) or
acoustic neuroma (a benign tumor of the nerve sheath). No statistically signif-
icant association was found between mobile phone use and acoustic neuro-
ma. There was also no association between mobile phone use and gliomas
when all 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 associa-
tion was found between mobile phone use and one rare type of glioma, neu-
roepithelliomatous 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 Institute is ex-
1
pected to bear on the accuracy and repeatability of these results.