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The U.S. Food and
Drug Administration's
(FDA) Center for
Devices and Radio-
logical 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 radio
frequency energy (i.e., radio frequency
radiation) in the microwave range while being
used. They also emit very low levels of radio
frequency 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 adverse health effects
associated with the use of mobile phones.
U.S. FDA
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
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