Table of Contents
Advertisement
Appendix C
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 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 effect 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 from 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
Telecommunications Industry Association (CTIA) in particular is expected to lead to FDA
providing research 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:
1 Two groups of 18 people were exposed to simulated mobile phone signals under laboratory
conditions while they performed cognitive function test. 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.
2 In 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.
What is known about cases of human cancer that have been reported in
users of handheld mobile phones?
Some people who have used mobile phones have been diagnosed with brain cancer. But
it is important to understand that this type of cancer also occurs among people who have
not used mobile phones. In fact, brain cancer occurs in the U.S. population at a rate of
about 6 new cases per 100,000 people each year. At that rate, assuming 80 million users
of mobile phones (a number increasing at a rate of about 1 million per month), about 4800
cases of brain cancer would be expected each year among those 80 million people,
whether or not they used their phones. Thus it is not possible to tell whether any
82 Consumer Update
1
2
3
4
Advertisement
Table of Contents
