User's Manual

2. FDA Consumer Update
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 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 any
adverse health effects associated with the use of mobile phones.
What kinds of phones are in questions?
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 distance from the user (on the out side 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 to
humans. Second, many of the studies that showed increased tumor development used animals
that had already been treated with cancer-causing chemicals, and other studies exposed the
animals to the RF virtually continuously —up to 22 hours per day.