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safety to give additional protection for the public
and to account for any variations in measurements.
The U.S. Food and Drug
Administration's Center for
Devices and Radiological Health
Consumer Update on Mobile Phones
FDA has been receiving inquiries about the safety
of mobile phones, including cellular phones and
PCS phones. The following summarizes what is
known—and what remains unknown—about
whether these products can pose a hazard to
health, and what can be done to minimize any
potential risk. This information may be used to
respond to questions.
Why the concern?
Mobile phones emit low levels of radiofrequency
energy (i.e. radiofrequency radiation) in the
microwave range while being used. They also emit
very low levels of radiofrequency energy (RF),
considered non-significant, when in the stand-by
mode. It is well known that high levels of RF can
produce biological damage through heating effects
(this is how your microwave oven is able to cook
food). However, it is not known whether, to what
extent, or through what mechanism, lower levels of
RF might cause adverse health effects as well.
Although some research has been done to address
these questions, no clear picture of the biological
effects of this type of radiation has emerged to
date. Thus, the available science does not allow us
to conclude that mobile phones are absolutely safe,
or that they are unsafe. However, the available
scientific evidence does not demonstrate any
adverse health effects associated with the use of
mobile phones.
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 of mobile phones. First, it is uncertain
how to apply the results obtained in rats and mice
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