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Because this occurred in only a small number of
cases, the increased likelihood was too small to be
statistically significant.4
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 hand-held 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
individual's cancer arose because of the phone, or
whether it would have happened anyway. A key
question is whether the risk of getting a particular
form of cancer is greater among people who use
mobile phones than among the rest of the
population. One way to answer that question is to
compare the usage of mobile phones among
people with brain cancer with the use of mobile
phones among appropriately matched people
without brain cancer. This is called a case-control
study. The current case-control study of brain
cancers by the National Cancer Institute, as well as
the follow-up research to be sponsored by industry,
will begin to generate this type of information.