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know with certainty what the results of
such studies mean for human health.
Three large epidemiology studies have
been published since December 2000.
Between them, the studies investigated
any possible association between the
use of wireless phones and primary brain
cancer, glioma, meningioma, or acoustic
neuroma, tumors of the brain or salivary
gland, leukemia, or other cancers. None of
the studies demonstrated the existence of
any harmful health effects from wireless
phone RF exposures.
However, none of the studies can answer
questions about longterm exposures,
since the average period of phone use in
these studies was around three years.
5. What research is needed to decide
whether RF exposure from wireless
phones poses a health risk?
A combination of laboratory studies
and epidemiological studies of people
actually using wireless phones would
provide some of the data that are needed.
Lifetime animal exposure studies could
be completed in a few years. However,
very large numbers of animals would
be needed to provide reliable proof of
a cancer promoting effect if one exists.
Epidemiological studies can provide
data that is directly applicable to human
populations, but 10 or more years follow-
up may be needed to provide answers
about some health effects, such as
cancer.
This is because the interval between the
time of exposure to a cancer-causing
agent and the time tumors develop - if
they do may be many, many years. The
interpretation of epidemiological studies
is hampered by difficulties in measuring
actual RF exposure during day-to-day use
of wireless phones. Many factors affect
this measurement, such as the angle at
which the phone is held, or which model
of phone is used.
6. What is the FDA doing to find out
more about the possible health
effects of wireless phone RF?
The FDA is working with the U.S. National
Toxicology Program and with groups
of investigators around the world to
ensure that high priority animal studies
are conducted to address important
questions about the effects of exposure
to radiofrequency energy (RF). The FDA
has been a leading participant in the
World Health Organization International
Electromagnetic Fields (EMF) Project since
its inception in 1996. An influential result