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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. 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 predisposed 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 neu-roma, 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.
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The National Institutes of Health participates in some inter-agency
working group activities, as well. FDA shares regulatory responsibilities
for wireless phones with the Federal Communications Commission
(FCC). All phones that are sold in the United States must comply with
FCC safety guidelines that limit RF exposure. FCC relies on FDA and
other health agencies for safety questions about wireless phones. FCC
also regulates the base stations that the wireless phone networks rely
upon. While these base stations operate at higher power than do the
wireless phones themselves, the RF exposures that people get from
these base stations are typically thousands of times lower than those
they can get from wireless phones. Base stations are thus not the
subject of the safety questions discussed in this document.
3. What kinds of phones are the subject of this update?
The term “wireless phone” refers here to hand-held wireless phones
with built-in antennas, often called “cell,” “mobile,” or “PCS” phones.
These types of wireless phones can expose the user to measurable
radiofrequency energy (RF) because of the short distance between the
phone and the user’s head. These RF exposures are limited by Federal
Communications Commission safety guidelines that were developed
with the advice of FDA and other federal health and safety agencies.
When the phone is located at greater distances from the user, the
exposure to RF is drastically lower because a person’s RF exposure
decreases rapidly with increasing distance from the source. The so-
called “cordless phones,” which have a base unit connected to the
telephone wiring in a house, typically operate at far lower power levels,
and thus produce RF exposures far below the FCC safety limits.
SAFETY AND WARRANTY
