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48
Regulatory Statem
ents
16
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
1
.
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
2
.
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 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
3
.
2
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
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.
What is FDA’s role concerning the safety of
mobile phones?
Under the law, FDA does not review the safety of
radiation-emitting consumer products such as
mobile phones before marketing, as it does with new
drugs or medical devices. However, the agency has
authority to take action if mobile phones are shown
to emit radiation at a level that is hazardous to the
user. In such a case, FDA could require the
manufacturers of mobile phones to notify users of the
health hazard and to repair, replace or recall the
phones so that the hazard no longer exists. Although
the existing scientific data do not justify FDA
