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For Your Safety
laboratory animals. However, many of the studies that showed increased tumor
development used animals that had been genetically 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 phones, 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
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 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
phones. Many factors affect this measurement, such as the angle at which the
phone is held, or which model of phone is used.
