Appendix C
82 Consumer Update
The Basics
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 ne rv e sheath). No stat isti cally si gnifi cant as soc iation was found between mobile
phone use and acoustic neur oma. There was also no associ ation bet ween mobile phone us e
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, neuroepithelliomat ous tumors. It is
possible with multiple comparis ons of the same sample that this associat ion occurred by
chance. Moreover, the risk did not incre ase with how often the mobile phone was used, or
the length of the calls. In fac t, the risk actually decreased with cumulative ho urs 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 Researc hers condu cted a la rge batt ery of la borato ry te s ts to a sse ss t he effec t of expos ure t o
mobile phone RF on genetic material. These included tests for sev eral kinds of
abnormalities, including mutations, chromosomal aberrations, DNA strand breaks, and
struct ural chang es in th e genetic material of blood cells calle d lymphocy tes. None of the te sts
showed any effect from the RF except for the micro nucleus assay, which detects structural
effects on the genetic material. The cells in this assay showed changes after exposure to
simulated cell phone rad i ation, but only after 24 hours of exposure. It is pos sible that
exposing t he tes t cells to radiatio n for t his long result ed i n heatin g. Sinc e this assay is known
to be sensit ive to heat ing, heat alo ne could hav e caused the abn ormaliti es to occur. The data
alread y in the literature on t he response of the micronucleus assay to RF are conflicting.
Thus, follow-up research is necessary.2
FDA is currently working with gove rnment, industry, and academic groups to ens ure the
proper follow-up to these industry-fun ded research findings. Collaboration with the Cellular
Telecommunic ations Indus try Association (CTI A) in particular is expected to lead to FDA
providing research recommendations and scientifi c 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
condit ions while they performed cognitive function test. There were no changes in th e
subjects’ ability to recall words, numbers, or pictures, or in their spat ial memory, but they
were able to mak e choices more quickly in one visual te st when they were expose d to
simulated mobile phone signals. This was t he only change noted among more than 20
variables compared.3
2 In study of 209 brain tumor cases and 425 matched controls, there was no incre ased risk of
brain tumors associated wit h 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 answ ers 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