Siemens SX66 User Manual page 21

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.
FDA is currently working with government, industry, and academic groups to ensure the proper
follow-up to these industry-funded research findings. Collaboration with the Cellular Telecom-
munications Industry Association (CTIA) in particular is expected to lead to FDA providing re-
search recommendations and scientific oversight of new CTIA-funded research based on such
recommendations.
Two other studies of interest have been reported recently in the literature:
• Two groups of 18 people were exposed to simulated mobile phone signals under laboratory
conditions while they performed cognitive function tests. There were no changes in the subjects'
ability to recall words, numbers, or pictures, or in their spatial memory, but they were able to
make choices more quickly in one visual test when they were exposed to simulated mobile phone
signals. This was the only change noted among more than 20 variables compared.
• In a study of 209 brain tumor cases and 425 matched controls, there was no increased risk
of brain tumors associated with mobile phone use. When tumors did exist in certain locations,
however, they were more likely to be on the side of the head where the mobile phone was used.
Because this occurred in only a small number of cases, the increased likelihood was too small
to be statistically significant.
In summary, we do not have enough information at this point to assure the public that there
are, or are not, any low incident health problems associated with use of mobile phones. FDA
continues to work with all parties, including other federal agencies and industry, to assure that
research is undertaken to provide the necessary answers to the outstanding questions about
the safety of mobile phones.
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