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 phones 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.
What research is needed to decide whether
RF exposure from wireless phones poses a
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
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.
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 radio frequency energy (RF).