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The 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. The FCC relies on the FDA and other health agencies for safety questions about wireless phones.
The 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 handheld wireless phones with built-in antennas, often called "cell",
"mobile", or "PCS" phones. These types of wireless phones can expose the user to measurable Radio Frequency
(RF) energy because of the short distance between the phone and the user's head. These RF exposures are
limited by FCC safety guidelines that were developed with the advice of the 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 Radio Frequency (RF) energy
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 12 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 do not 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, 166 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
ten or more years followup 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 cancercausing 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 the FDA doing to find out more about the possible health effects of wireless phone RF?
The 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 Radio Frequency (RF) energy. The FDA has been a leading participant in the World Health
Organization International Electro Magnetic 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. The FDA and the Cellular Telecommunications & Internet Association (CTIA) have a
formal Cooperative Research And Development Agreement (CRADA) to do research on wireless phone safety. 13
The FDA provides the scientific oversight, obtaining input from experts in government, industry, and academic
organizations. CTIAfunded research is conducted through contracts with 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 Radio Frequency 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 Radio Frequency (RF) energy exposures. The FCC established these guidelines in consultation with
the FDA and the other federal health and safety agencies. The FCC limit for RF exposure from wireless phones
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 the FDA done to measure the Radio Frequency energy coming from wireless phones?
The Institute of Electrical and Electronic Engineers (IEEE) is developing a technical standard for measuring the
Radio Frequency (RF) energy 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 Radio Frequency 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 Radio Frequency (RF) energy. 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 does 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 Radio Frequency (RF) energy, 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