U.s. Fda - Siemens A71 Manual

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U.S. FDA

24
U.S. FDA
The U.S. Food and Drug Administration's
(FDA) Center for Devices and Radiologi-
cal Health Consumer Update on Mobile
Phones
FDA has been receiving inquiries about
the safety of mobile phones, including
cellular phones and PCS phones. The fol-
lowing summarizes what is know – and
what remains unknown – about whether
these products can pose a hazard to
health, and what can be done to mini-
mize 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), consid-
ered 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 mecha-
nism, lower levels of RF might cause ad-
verse health effects as well. Although
some research has been done to address
these questions, no clear picture of the bi-
ological 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 avail-
able scientific evidence does not demon-
strate 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 tele-
phone conversation. These types of mo-
bile phones are of concern because of the
short distance between the phone's an-
tenna – the primary source of the RF –
and the person's head. The exposure to
RF from mobile phones in which the an-
tenna is located at greater distances from
the user (on the outside of a car, for ex-
ample) 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 mo-
bile phones might be harmful?
Briefly, there is not enough evidence to
know for sure, either way; however, re-
search 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 de-
velopment of cancer in laboratory ani-
mals. In one study, mice genetically al-
tered 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 showed increased tumor de-