Nokia 6235 Manual Del Usuario página 103

A d d i t i o n a l s a f e t y i n f o r m a t i o n
in other laboratories. A few animal studies, however, have suggested that low
levels of RF could accelerate the development of cancer in 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 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 device is held, or which model of phone is used.
6. What is FDA doing to find out more about the possible health effects of
wireless phone RF?
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).
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