• A MESSAGE FROM THE FDA
July 18, 2001
For updates: http://www.fda.gov/cdrh/phones
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Consumer Update on Wireless Phones
U.S. Food and Drug Administration
1. Do wireless phones pose a health hazard?
The available scientific evidence does not show that any health problems are associated
with using wireless phones. There is no proof, however, that wireless phones are
absolutely safe. Wireless phones emit low levels of radiofrequency energy (RF) in the
microwave range while being used. They also emit very low levels of RF when in the
stand-by mode. Whereas high levels of RF can produce health effects (by heating
tissue), exposure to low level RF that does not produce heating effects causes no known
adverse health effects. Many studies of low level RF exposures have not found any
biological effects. Some studies have suggested that some biological effects may occur,
but such findings have not been confirmed by additional research. In some cases, other
researchers have had difficulty in reproducing those studies, or in determining the
reasons for inconsistent results.
2. What is FDA's role concerning the safety of wireless phones?
Under the law, FDA does not review the safety of radiation-emitting consumer products
such as wireless phones before they can be sold, as it does with new drugs or medical
devices. However, the agency has authority to take action if wireless phones are shown
to emit radiofrequency energy (RF) at a level that is hazardous to the user. In such a
case, FDA could require the manufacturers of wireless phones to notify users of the
health hazard and to repair, replace or recall the phones so that the hazard no longer
exists.
Although the existing scientific data do not justify FDA regulatory actions, FDA has
urged the wireless phone industry to take a number of steps, including the following:
•
Support needed research into possible biological effects of RF of the type emitted
by wireless phones;
•
Design wireless phones in a way that minimizes any RF exposure to the user that
is not necessary for device function; and
•
Cooperate in providing users of wireless phones with the best possible information
on possible effects of wireless phone use on human health.
FDA belongs to an interagency working group of the federal agencies that have
responsibility for different aspects of RF safety to ensure coordinated efforts at the
federal level. The following agencies belong to this working group:
•
National Institute for Occupational Safety and Health
•
Environmental Protection Agency
•
Federal Communications Commission
•
Occupational Safety and Health Administration
•
National Telecommunications and Information Administration
The National Institutes of Health participates in some interagency working group
activities, as well.
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FDA shares regulatory responsibilities for wireless phones with the Federal
Communications Commission (FCC). All phones that are sold in the United States must
comply with FCC safety guidelines that limit RF exposure. FCC relies on FDA and other
health agencies for safety questions about wireless phones.
FCC also regulates the base stations that the wireless phone networks rely upon. While
these base stations operate at higher power than do the wireless phones themselves,
the RF exposures that people get from these base stations are typically thousands of
times lower than those they can get from wireless phones. Base stations are thus not
the subject of the safety questions discussed in this document.
3. What kinds of phones are the subject of this update?
The term wireless phone refers here to hand-held wireless phones with built-in
antennas, often called cell mobile or PCS phones. These types of wireless phones can
expose the user to measurable radiofrequency energy (RF) because of the short distance
between the phone and the user’s head. These RF exposures are limited by Federal
Communications Commission safety guidelines that were developed with the advice of
FDA and other federal health and safety agencies. When the phone is located at greater
distances from the user, the exposure to RF is drastically lower because a person's RF
exposure decreases rapidly with increasing distance from the source. The so-called
cordless phones; which have a base unit connected to the telephone wiring in a house,
typically operate at far lower power levels, and thus produce RF exposures far below the
FCC safety limits.
4. What are the results of the research done already?
The research done thus far has produced conflicting results, and many studies have
suffered from flaws in their research methods. Animal experiments investigating the
effects of radiofrequency energy (RF) exposures characteristic of wireless phones have
yielded conflicting results that often cannot be repeated in other laboratories. A few
animal studies, however, have suggested that low levels of RF could accelerate the
development of cancer in laboratory animals. However, many of the studies that showed
increased tumor development used animals that had been genetically engineered or
treated with cancer-causing chemicals so as to be pre-disposed to develop cancer in
the absence of RF exposure. Other studies exposed the animals to RF for up to 22 hours
per day. These conditions are not similar to the conditions under which people use
wireless phones, so we don’t know with certainty what the results of such studies mean
for human health.
Three large epidemiology studies have been published since December 2000. Between
them, the studies investigated any possible association between the use of wireless
phones and primary brain cancer, glioma, meningioma, or acoustic neuroma, tumors of
the brain or salivary gland, leukemia, or other cancers. None of the studies
demonstrated the existence of any harmful health effects from wireless phone RF
exposures. However, none of the studies can answer questions about long-term
exposures, since the average period of phone use in these studies was around three
years.
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5. What research is needed to decide whether RF exposure from wireless
phones poses a health risk?
A combination of laboratory studies and epidemiological studies of people actually
using wireless phones would provide some of the data that are needed. Lifetime animal
exposure studies could be completed in a few years. However, very large numbers of
animals would be needed to provide reliable proof of a cancer promoting effect if one
exists. Epidemiological studies can provide data that is directly applicable to human
populations, but 10 or more years follow-up may be needed to provide answers about
some health effects, such as cancer. This is because the interval between the time of
exposure to a cancer-causing agent and the time tumors develop - if they do - may be
many, many years. The interpretation of epidemiological studies is hampered by
difficulties in measuring actual RF exposure during day-to-day use of wireless phones.
Many factors affect this measurement, such as the angle at which the phone is held, or
which model of phone is used.
6. What is FDA doing to find out more about the possible health effects
of wireless phone RF?
FDA is working with the U.S. National Toxicology Program and with groups of
investigators around the world to ensure that high priority animal studies are
conducted to address important questions about the effects of exposure to
radiofrequency energy (RF).
FDA has been a leading participant in the World Health Organization International
Electromagnetic Fields (EMF) Project since its inception in 1996. An influential result of
this work has been the development of a detailed agenda of research needs that has
driven the establishment of new research programs around the world. The Project has
also helped develop a series of public information documents on EMF issues.
FDA and the Cellular Telecommunications
&
Internet Association (CTIA) have a formal
Cooperative Research and Development Agreement (CRADA) to do research on wireless
phone safety. FDA provides the scientific oversight, obtaining input from experts in
government, industry, and academic organizations. CTIA-funded research is conducted
through contracts to independent investigators. The initial research will include both
laboratory studies and studies of wireless phone users. The CRADA will also include a
broad assessment of additional research needs in the context of the latest research
developments around the world.
7. How can I find out how much radiofrequency energy exposure I can get
by using my wireless phone?
All phones sold in the United States must comply with Federal Communications
Commission (FCC) guidelines that limit radiofrequency energy (RF) exposures. FCC
established these guidelines in consultation with FDA and the other federal health and
safety agencies. The FCC limit for RF exposure from wireless telephones is set at a
Specific Absorption Rate (SAR) of 1.6 watts per kilogram (1.6 W/kg). The FCC limit is
consistent with the safety standards developed by the Institute of Electrical and
Electronic Engineering (IEEE) and the National Council on Radiation Protection and
Measurement. The exposure limit takes into consideration the body’s ability to remove
heat from the tissues that absorb energy from the wireless phone and is set well below
levels known to have effects.
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Manufacturers of wireless phones must report the RF exposure level for each model of
phone to the FCC. The FCC website (http://www.fcc.gov/oet/rfsafety) gives directions for
locating the FCC identification number on your phone so you can find your phone’s RF
exposure level in the online listing.
8. What has FDA done to measure the radiofrequency energy coming from
wireless phones?
The Institute of Electrical and Electronic Engineers (IEEE) is developing a technical
standard for measuring the radiofrequency energy (RF) exposure from wireless phones
and other wireless handsets with the participation and leadership of FDA scientists and
engineers. The standard, Recommended Practice for Determining the Spatial-Peak
Specific Absorption Rate (SAR) in the Human Body Due to Wireless Communications
Devices: Experimental Techniques, sets forth the first consistent test methodology for
measuring the rate at which RF is deposited in the heads of wireless phone users. The
test method uses a tissue-simulating model of the human head. Standardized SAR test
methodology is expected to greatly improve the consistency of measurements made at
different laboratories on the same phone. SAR is the measurement of the amount of
energy absorbed in tissue, either by the whole body or a small part of the body. It is
measured in watts/kg (or milliwatts/g) of matter. This measurement is used to
determine whether a wireless phone complies with safety guidelines.
9. What steps can I take to reduce my exposure to radiofrequency energy
from my wireless phone?
If there is a risk from these products--and at this point we do not know that there is--
it is probably very small. But if you are concerned about avoiding even potential risks,
you can take a few simple steps to minimize your exposure to radiofrequency energy
(RF). Since time is a key factor in how much exposure a person receives, reducing the
amount of time spent using a wireless phone will reduce RF exposure.
If you must conduct extended conversations by wireless phone every day, you could
place more distance between your body and the source of the RF, since the exposure
level drops off dramatically with distance. For example, you could use a headset and
carry the wireless phone away from your body or use a wireless phone connected to a
remote antenna.
Again, the scientific data do not demonstrate that wireless phones are harmful. But if
you are concerned about the RF exposure from these products, you can use measures
like those described above to reduce your RF exposure from wireless phone use.
10. What about children using wireless phones?
The scientific evidence does not show a danger to users of wireless phones, including
children and teenagers. If you want to take steps to lower exposure to radiofrequency
energy (RF), the measures described above would apply to children and teenagers using
wireless phones. Reducing the time of wireless phone use and increasing the distance
between the user and the RF source will reduce RF exposure.Some groups sponsored by
other national governments have advised that children be discouraged from using
wireless phones at all. For example, the government in the United Kingdom distributed
leaflets containing such a recommendation in December 2000. They noted that no
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evidence exists that using a wireless phone causes brain tumors or other ill effects. Their
recommendation to limit wireless phone use by children was strictly precautionary; it
was not based on scientific evidence that any health hazard exists.
11. What about wireless phone interference with medical equipment?
Radiofrequency energy (RF) from wireless phones can interact with some electronic
devices. For this reason, FDA helped develop a detailed test method to measure
electromagnetic interference (EMI) of implanted cardiac pacemakers and defibrillators
from wireless telephones. This test method is now part of a standard sponsored by the
Association for the Advancement of Medical instrumentation (AAMI). The final draft, a
joint effort by FDA, medical device manufacturers, and many other groups, was
completed in late 2000. This standard will allow manufacturers to ensure that cardiac
pacemakers and defibrillators are safe from wireless phone EMI. FDA has tested hearing
aids for interference from handheld wireless phones and helped develop a voluntary
standard sponsored by the Institute of Electrical and Electronic Engineers (IEEE). This
standard specifies test methods and performance requirements for hearing aids and
wireless phones so that no interference occurs when a person uses a compatible phone
and a accompanied hearing aid at the same time. This standard was approved by the
IEEE in 2000.
FDA continues to monitor the use of wireless phones for possible interactions with other
medical devices. Should harmful interference be found to occur, FDA will conduct
testing to assess the interference and work to resolve the problem.
12. Where can I find additional information?
For additional information, please refer to the following resources:
•
FDA web page on wireless phones
http://www.fda.gov/cdrh/phones/index.html
•
Federal Communications Commission (FCC) RF Safety Program
http://www.fcc.gov/oet/rfsafety
•
International Commission on Non-Ionizing Radiation Protection
http://www.icnirp.de
•
World Health Organization (WHO) International EMF Project
http://www.who.int/emf
•
National Radiological Protection Board (UK)
http://www.nrpb.org.uk/
July 18, 2001For updates: http://www.fda.gov/cdrh/phones
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