User's Manual
formed 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 con
-
trols, 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 like
-
lihood 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 con
-
tinues 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 diag
-
nosed 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.
popula
-
tion
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
I
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 peo
-
ple with brain cancer with the use of mobile phones among