User Manual

APPENDIX
156
The National Institutes of Health participates in some interagency 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.
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 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.