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Safety
pre-disposed to develop cancer in the absence of RF exposure. Other
studies exposed the animals to RF for up to 22 hours per day. These
conditions are not similar to the conditions under which people use
wireless devices, so we do not 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 devices
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 device RF exposures. However, none of the studies can answer
questions about long-term exposures, since the average period of wireless
device use in these studies was around three years.
5. What research is needed to decide whether RF exposure from
wireless devices poses a health risk?
A combination of laboratory studies and epidemiological studies of people
actually using wireless devices 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 ten 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 devices. Many factors affect
this measurement, such as the angle at which the wireless device is held,
or which model of wireless device is used.
6. What is the FDA doing to find out more about the possible health
effects of wireless device 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