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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 subject of this update?
The term “wireless phone” refers here to handheld 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 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
