VX3100
111
VX3100
110
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?
Acombination 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 anime 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.
6. What is FDAdoing 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
S
AFETY
G
UIDELINES
produce RF exposures far below the FCC safety
limits.
4. What are the results of the research done already?
The research done thus far has produced conflicting
results, and many studies have suffered from flaws
in their research methods. Animal experiments
investigating the effects of radiofrequency energy
(RF) exposures characteristic of wireless phones
have yielded conflicting results that often cannot be
repeated in other laboratories. Afew 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,
VX3100.qxd 4/26/03 12:21 PM Page 110