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How much evidence is there that
hand-held mobile phones might
be harmful?
Briefly,there is not enough evi-
dence to know forsure, either way;
however,research efforts are on-
going.The existing scientific evi-
dence is conflicting and many of
the studies that have been done to
date have suffered from flaws in
theirresearch methods.
Animal experiments investigating
the effects of RF exposures charac-
teristic of mobile phones have
yielded conflicting results.A few
animal studies,however, have sug-
gested that low levels of RF could
accelerate the development of can-
cerin laboratory animals.
In one study,mice genetically
altered to be predisposed to devel-
oping one type of cancerdevel-
oped 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 stud-
ies 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 tumordevelop-
ment used animals that had already
been treated with cancer-causing
chemicals,and other studies
exposed the animals to the RF vir-
tually continuously – up to 22 hours
perday.
Forthe past five years in the
United States,the mobile phone
industry has supported research
into the safety of mobile phones.
This research has resulted in two
findings in particularthat merit
additional study:
• In a hospital-based,case-control
study,researchers looked foran
association between mobile phone
use and eitherglioma (a type of
brain cancer) oracoustic neuroma
(a benign tumorof the nerve
sheath).No statistically significant
association was found between
mobile phone use and acoustic
neuroma.
There was also no association
between mobile phone use and
gliomas when all types of gliomas
were considered together. It
should be noted that the average
length of mobile phone exposure in
this study was less than three
years.
When 20 types of glioma were
considered separately,however,an
association was found between
mobile phone use and one rare
type of glioma,neuroepithellioma-
tous tumors.It is possible with
multiple comparisons of the same
sample that this association
occurred by chance.
Moreover,the risk did not
increase with how often the mobile
phone was used,or the length of
the calls.In fact, the risk actually
decreased with cumulative hours
of mobile phone use.
FDA Update on mobile phone safety
The U.S.Food and Drug
Administration’s Centerfor
Devices and Radiological Health
ConsumerUpdate on Mobile
Phones
FDA has been receiving inquiries
about the safety of mobile phones,
including cellularphones and PCS
phones. The following summarizes
what is known – and what remains
unknown – about whetherthese
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),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 yourmicrowave
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 ques-
tions,no clear picture of the biolog-
ical 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.
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 conversa-
tion.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 per-
son’s head.
The exposure to RF from mobile
phones in which the antenna is
located at greaterdistances from
the user(on the outside of a car,
forexample) is drastically lower
than that from hand-held phones,
because a person’s RF exposure
decreases rapaidly 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
lowerpower levels and frequen-
cies,has not been questioned.
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