engineered or treated with cancer-causing chemicals so
as to be 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 device use in these studies
was around three years.
5. What research is needed to decide whether RF
exposure from tablets poses a health risk?
A combination of laboratory studies and epidemiological
studies of people actually using tablets 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
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