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Safety Guidelines
animals to RF for up to 22 hours per day.
These conditions are not similar to the
conditions under which people use wireless
phones, so we don’t 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 long-term 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
