Motorola C331 User Manual page 151

What kinds of phones are in question?
Questions have been raised about hand-held mobile phones,
the kind that have a built-in antenna that is positioned close to
the user's head during normal telephone conversation. These
types of mobile phones are of concern because of the short
distance between the phone's antenna—the primary source
of the RF—and the person's head. The exposure to RF from
mobile phones in which the antenna is located at greater
distances from the user (on the outside of a car, for example)
is drastically lower than that from hand-held phones, because
a person's RF exposure decreases rapidly with distance from
the source. The safety of so-called "cordless phones," which
have a base unit connected to the telephone wiring in a house
and which operate at far lower power levels and frequencies,
has not been questioned.
How much evidence is there that hand-held
mobile phones might be harmful?
Briefly, there is not enough evidence to know for sure, either
way; however, research efforts are on-going. The existing
scientific evidence is conflicting and many of the studies that
have been done to date have suffered from flaws in their
research methods. Animal experiments investigating the
effects of RF exposures characteristic of mobile phones have
yielded conflicting results. A few animal studies, however,
have suggested that low levels of RF could accelerate the
development of cancer in laboratory animals. In one study,
mice genetically altered to be predisposed to developing one
type of cancer developed more than twice as many such
cancers when they were exposed to RF energy compared to
controls. There is much uncertainty among scientists about
whether results obtained from animal studies apply to the use
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