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.
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?
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Appendix B Message from the FDA
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.
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.
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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.
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.
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Appendix B Message from the FDA
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 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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