Telecommunications: Status of Research on the Safety of Cellular
Telephones (Chapter Report, 11/04/94, GAO/RCED-95-32).
On the basis of present scientific knowledge, federal agencies have no
reason to take regulatory action on the use of portable cellular
telephones because no research has been completed on long-term human
exposure to the low levels of radiation generated by these phones and
research findings on exposure to other sources of low-level
radio-frequency radiation are inconclusive. According to the Food and
Drug Administration (FDA) and the National Science Foundation, both
epidemiological and laboratory studies are needed to determine any link
between cellular telephone use and human diseases. The cellular
telecommunications industry plans to do both types of studies. If
federal regulators want to use this research, they need assurances that
it will be carried out objectively. FDA is working with cellular
telephone manufacturers on the possibility of redesigning portable
cellular telephone and on providing users with instruction for proper
use. The Federal Communications Commission has proposed revising
standards set by the American National Standards Institute for
radio-frequency radiation; this standard may be applied to cellular
telephones.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: RCED-95-32
TITLE: Telecommunications: Status of Research on the Safety of
Cellular Telephones
DATE: 11/04/94
SUBJECT: Consumer protection
Telecommunications equipment
Telephone communications operations
Product safety
Radiation exposure hazards
Cancer research
Motor vehicles
Health hazards
Regulatory agencies
Public health research
**************************************************************************
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Cover
================================================================ COVER
Report to the Chairman, Subcommittee on Telecommunications and
Finance, Committee on Energy and Commerce, House of Representatives
November 1994
TELECOMMUNICATIONS - STATUS OF
RESEARCH ON THE SAFETY OF CELLULAR
TELEPHONES
GAO/RCED-95-32
Safety of Cellular Telephones
Abbreviations
=============================================================== ABBREV
ANSI - American National Standards Institute, Inc.
CDMA - code division multiple access
CTIA - Cellular Telephone Industry Association
DOD - Department of Defense
EPA - Environmental Protection Agency
FDA - Food and Drug Administration
FCC - Federal Communications Commission
GAO - General Accounting Office
IEEE - Institute of Electrical and Electronics Engineers, Inc.
MHz - megahertz
mW - milliwatt
NCI - National Cancer Institute
NEPA - National Environmental Policy Act of 1969
NIH - National Institutes of Health
NIST - National Institute of Standards and Technology
TDMA - time division multiple access
Letter
=============================================================== LETTER
B-258115
November 4, 1994
The Honorable Edward J. Markey
Chairman, Subcommittee on
Telecommunications and Finance
Committee on Energy and Commerce
House of Representatives
Dear Mr. Chairman:
In response to your request, this report addresses the status of
scientific knowledge on the biological effects of the radio-frequency
radiation that portable cellular telephones emit and the federal
government's regulatory actions to ensure the safety of these
telephones. The report contains a recommendation aimed at increasing
the potential usefulness to federal agencies of a current industry
research initiative.
As agreed with your office, unless you publicly announce its contents
earlier, we plan no further distribution of this report until 30 days
after the date of this letter. At that time, we will send copies to
the commissioners of the Federal Communications Commission, the
Commissioner of the Food and Drug Administration, the Administrator
of the Environmental Protection Agency, and other interested parties.
We will also make copies available to others on request.
This report was prepared under the direction of Kenneth M. Mead,
Director, Transportation and Telecommunications Issues, who may be
reached on (202) 512-2834 if you and your staff have any questions.
Major contributors to this report are listed in appendix VI.
Sincerely yours,
Keith O. Fultz
Assistant Comptroller General
EXECUTIVE SUMMARY
============================================================ Chapter 0
PURPOSE
---------------------------------------------------------- Chapter 0:1
Over 16 million Americans now use cellular telephones--about a third
of which are hand-held portable cellular telephones--and the industry
estimates that by the year 2000 over 60 million people will be using
a portable cellular communications device. In response to reports in
the media alleging that hand-held cellular telephones may pose a
health risk, the Chairman, Subcommittee on Telecommunications and
Finance, House Committee on Energy and Commerce, asked GAO to review
(1) the status of scientific knowledge on the potential health risks
of the radio-frequency radiation emitted by portable cellular
telephones and the status of federal involvement in any related
research and (2) the actions of responsible federal agencies to
ensure the safety of cellular telephones.
BACKGROUND
---------------------------------------------------------- Chapter 0:2
All devices that transmit radio-frequency signals--such as radio
broadcast towers and cellular telephones--emit radio-frequency
radiation. At sufficient power levels, radio-frequency radiation can
produce immediate biological damage, such as burns (thermal effects).
The American National Standards Institute's (ANSI) 1982 standard for
radiation exposure indicates that devices operating on 7 watts or
less of power at frequencies below 1,000 megahertz will not produce
immediate thermal effects. Portable cellular telephones operate on
much less than 7 watts of power (up to a maximum of only 0.6 watts)
at frequencies between 800 and 900 megahertz. While the telephones
operate below the threshold for thermal effects, the low-level
radiation emitted from an antenna that is held close to the user's
head raises questions about whether long-term exposure to low-level
radiation near the body can also produce biological damage.
Several federal agencies play a role in ensuring the safety of
cellular telephones. The Federal Communications Commission (FCC)
approves cellular telephones for use and is responsible for ensuring
that FCC-approved equipment does not emit radiation at levels
determined to adversely affect the human environment. To ensure
electronic product safety, the Food and Drug Administration (FDA) is
responsible for establishing performance standards for products that
emit radiation and for conducting, coordinating, and supporting
research to minimize the emission of, and exposure of people to, such
radiation. The agency reviews industry research on products and may
subsequently use such research in carrying out its responsibilities
for product safety. It also works with manufacturers on the
voluntary redesign of equipment as a cost-effective strategy when
safety questions are raised but the scientific evidence does not
necessarily justify issuing a performance standard. The
Environmental Protection Agency (EPA) is responsible for advising the
President on radiation matters, including providing guidance to other
federal agencies on permissible levels of exposure to radio-frequency
radiation.
RESULTS IN BRIEF
---------------------------------------------------------- Chapter 0:3
No research has been completed on long-term human exposure to low
levels of radiation specifically from portable cellular telephones.
Research findings on exposure to other sources of low-level
radio-frequency radiation are inconclusive. Some laboratory studies
show that biological effects can occur when animals and cells have
undergone extended exposure to low-level radio-frequency radiation;
others do not. Scientists at FDA and EPA said that existing research
does not provide enough evidence to determine whether portable
cellular telephones pose a risk to human health. The National
Institutes of Health (NIH) is beginning an epidemiological study,
which could determine the relationship between portable cellular
telephone use and disease.\1 However, according to FDA and the
National Science Foundation, both epidemiological and laboratory
studies are needed to determine any linkage between the use of
portable cellular telephones and adverse health effects. The
cellular telecommunications industry is planning to do both types of
studies. If federal regulators want to use this research, they need
to be assured that it is carried out objectively.
On the basis of present scientific knowledge, FDA and EPA have had no
reason to take regulatory actions on the use of portable cellular
telephones. However, FDA, consistent with its adherence to the
principle that human exposure to radiation should be "as low as
reasonably achievable," is working with cellular telephone
manufacturers on the possibility of redesigning portable cellular
telephones and on providing users with instructions for proper use.
FCC has proposed adopting a revised ANSI standard for equipment it
approves; this standard may be applied to cellular telephones.
--------------------
\1 An epidemiological study is a statistical study that relates the
occurrence of a disease to the characteristics of people and their
environment.
PRINCIPAL FINDINGS
---------------------------------------------------------- Chapter 0:4
STATUS OF RESEARCH
-------------------------------------------------------- Chapter 0:4.1
Studies on exposure to low levels of radio-frequency radiation from
sources other than portable cellular telephones have found biological
and behavioral effects in animals and certain cell systems. However,
both FDA and EPA believe that the evidence is insufficient to
conclude that these effects pose a health risk to humans as a result
of exposure to radio-frequency radiation from low-power sources like
portable cellular telephones.
The federal government is beginning research that specifically
focuses on the safety of cellular telephone use. For example, NIH's
National Cancer Institute has begun an epidemiological study of
patients with brain cancer to determine if there is a statistical
relationship between cellular telephone use and cancer. However,
controlled laboratory studies on animals and living cells are also
needed, according to FDA and the National Science Foundation, to
determine if radiation from portable cellular telephones poses a
human health risk. The Cellular Telecommunications Industry
Association is funding a science advisory group that will sponsor
research on the safety of cellular telephones. This research
initiative, which includes human and laboratory studies, could
provide the kind of comprehensive information necessary to assess the
health risks of cellular telephones. To the extent that federal
regulators may want to use this research, they will need to be
assured that the research is well designed and carried out
objectively. The chairman of the advisory group said that it would
be open to federal participation in order to increase the acceptance
and usefulness of the research.
FEDERAL ACTIONS ARE LIMITED
-------------------------------------------------------- Chapter 0:4.2
When evidence is insufficient to justify developing a product
standard, FDA sometimes works with manufacturers of electronic
products to develop voluntary precautionary measures. In the case of
portable cellular telephones, FDA has been working with manufacturers
on the possibility of redesigning the placement of the antenna so
that this source of radiation is farther from the user's head. It
also is working with manufacturers on practical instructions for use
to limit users' exposure to radiation. Unless future research
provides sufficient evidence of a health problem, or a substantial
number of complaints are filed with FDA, the agency does not plan to
use its limited resources to develop product standards for portable
cellular telephones. Instead, it plans to undertake higher-priority
research--on the safety of medical devices, for example.
EPA is working on developing exposure limits to protect the public
from exposure to high levels of radiation. However, the agency said
that present scientific information does not provide a basis for
recommending exposure limits for low-level radiation--the type
emitted by cellular telephones. EPA has funded a 2-year study by the
National Council on Radiation Protection and Measurements to gain a
better understanding of the status of research on the effects of
long-term exposure to low levels of radio-frequency radiation and
future research needs.
FCC does not consider itself a health agency and turns to health and
radiation experts outside the agency for guidance on these issues.
There are no federal product safety standards for cellular
telephones, and because there is no federal guidance on radiation
exposure limits, FCC has incorporated the 1982 ANSI standard into its
environmental rules. The Commission considers portable cellular
telephones safe under this standard. However, FCC has proposed
updating its environmental rules by adopting the revised version of
the ANSI standard. According to an agency official, portable
cellular telephones could then become subject to routine
environmental evaluation for radiation emissions before FCC approves
them for use.
RECOMMENDATION
---------------------------------------------------------- Chapter 0:5
GAO recommends that the Commissioner of the Food and Drug
Administration and the Administrator of the Environmental Protection
Agency, in coordination with the Chairman of the Federal
Communications Commission, work with the industry's Science Advisory
Group on Cellular Telephone Safety to maximize the usefulness,
independence, and objectivity of the group's planned research
initiative. This effort could include participating in the selection
of research proposals to determine whether they meet federal research
standards and reviewing research results. This effort would be in
addition to ongoing and planned federal research.
AGENCY COMMENTS
---------------------------------------------------------- Chapter 0:6
GAO discussed a draft of this report with officials from (1) FDA's
Office of Science and Technology, including the Chief of the
Radiation Biology Branch; (2) EPA's Office of Radiation and Indoor
Air, including the Electromagnetic Fields Team Leader in the
Radiation Studies Division; and (3) FCC's Office of Engineering and
Technology, including the Chief Engineer. The FDA and EPA officials
generally agreed that the information was accurate and that the
current state of scientific knowledge is insufficient to determine
whether portable cellular telephones pose health risks. In addition,
the FDA and EPA officials said they plan to review the industry's
completed research. These officials' comments have been incorporated
in the text as appropriate. As requested, GAO did not obtain written
agency comments on this report.
INTRODUCTION
============================================================ Chapter 1
Cellular telephones, first marketed in 1983, have become one of the
fastest selling consumer electronic products. By the end of 1993,
over 16 million Americans were using cellular telephones, and the
industry estimates that in less than a decade, over 60 million
Americans will be using a cellular communications device. About
one-third of all cellular telephones currently in use are hand-held
portable models, which are growing in popularity. Industry
forecasters predict a high demand for a new generation of personal
communications devices that will offer a greater range of uses.
Technology enthusiasts envision a future in which nearly all
Americans will have a wireless portable communications device.
CELLULAR COMMUNICATIONS
EQUIPMENT AND TECHNOLOGY
---------------------------------------------------------- Chapter 1:1
Cellular telephones come in a variety of styles, but all fall into
the following three general categories:
car telephones, in which the telephone is installed in the vehicle
and the antenna is mounted on the roof, trunk, or rear window;
transportable telephones, in which the telephone body, antenna, and
handset are carried in a briefcase or bag, but the handset is
separated from the body and antenna for use; and
portable telephones,\2 in which a self-contained handset houses a
battery and an antenna in a unit generally small enough to fit in a
purse or pocket.
Portable cellular telephones are the subject of this report
because--unlike with car telephones and transportable
telephones--their antenna is very close to the user's head when the
telephone is in use. Figure 1.1 shows some typical models of
portable cellular telephones and the proximity of the antenna to the
user's head.
(See figure in printed edition.)Figure 1.1: Four Typical Models of
Portable Cellular Telephones
(From left to right) Telephone A is an example of the first style of
hand-held portable cellular telephone; it is characterized by a bulky
body and a nonretractable antenna. It is heavier than most of the
newer portable cellular telephones. Telephone B is an example of the
"flip-style" cellular telephone; it features a mouthpiece that can be
folded over the keypad and a retractable antenna for storage while
not in use. Telephone C is an example of a nonflip-style telephone;
it has a shorter nonretractable antenna. Telephone D is the newest
style of portable cellular telephone; it is designed to transmit and
receive digital signals.
All devices that transmit radio signals--such as radio broadcast
towers and cellular telephones--emit radio-frequency radiation.
Radio-frequency radiation is electromagnetic energy emitted in the
form of waves. Cellular telephones transmit voice messages by
sending electronic signals from an antenna over radio waves at
frequencies between 824 and 894 megahertz (MHz).\3 These signals are
a form of radio-frequency radiation.
At sufficient power levels, radio-frequency radiation can heat body
tissue and cause biological damage such as burns. These effects of
exposure to radio-frequency radiation, called thermal effects, are
immediately observable. According to the 1982 American National
Standards Institute's (ANSI) standard for radiation exposure, a
nongovernment standard that some federal agencies use, devices
operating on 7 or less watts of power at frequencies below 1,000 MHz
will not produce immediate thermal effects.\4 Portable cellular
telephones operate on well below 7 watts of power. They use up to a
maximum of 0.6 watts of power--less than the amount of power required
to light a flashlight bulb. However, questions have been raised
about whether long-term or frequent exposures to low levels of
radio-frequency radiation have other biological effects that are
delayed or not immediately observed in human cells and animals.
Portable cellular telephones transmit messages to a cellular
transmitter tower. More power is required to transmit a signal when
the telephone is farther away from a tower. For example, if a caller
is located at a great distance from the tower, the telephone may use
the full 0.6 watts of power to transmit the signal. However, if the
caller is near the tower, the telephone may only need to use about
0.2 watts of power to transmit the signal.
Cellular telephones transmit either analog or digitized voice
messages, depending on the type of cellular telephone used and the
service available. In analog radio communication systems, messages
are transmitted by modulating, or varying, either the amplitude
(height) or the frequency (number of wave crests) of the radio wave.
In digital communication systems, messages are transmitted as a
series of digits in rapid bursts, or pulses. These are sometimes
referred to as pulse-modulated signals. An advantage of digital
transmission is that it increases channel capacity by allowing
several users to transmit messages over the same radio wave
simultaneously. As figure 1.2 shows, analog signals are continuous
radio waves, while digital signals are binary--usually represented by
ones and zeroes. (See app. I for additional information on these
two technologies.)
Figure 1.2: Analog and Digital
Signals
(See figure in printed
edition.)
The next generation of cellular communications is called personal
communications services. In this system, inexpensive, pocket-sized
communications devices that use digital technology will deliver
voice, data, and images. They will operate at higher radio
frequencies (between 1,850 and 2,200 MHz) and will likely use less
power to operate than the current generation of portable cellular
telephones. A personal communications device carried from place to
place will enable the person to be reached at any location by dialing
a single telephone number. Because personal communications services
devices are still under development, it is not clear whether the
antenna will be in close proximity to the user's head when the device
is in use.
--------------------
\2 Portable cellular telephones are not the same as the cordless
telephones commonly used in the home. Cordless telephones transmit
to a base unit connected to the telephone wiring in a house and
operate at far lower power levels and frequencies than portable
cellular telephones.
\3 Some other uses of radio frequencies are FM radio stations, which
broadcast between 88 and 108 MHz, and television stations, which
broadcast between 54 and 806 MHz. Microwave ovens heat food using
radio frequencies ranging from 890 to 6,000 MHz.
\4 Safety Levels With Respect to Human Exposure to Radio Frequency
Electromagnetic Fields, 300 kHz to 100 GHz, ANSI C95.1-1982, American
National Standards Institute, Inc. (1982).
FEDERAL REGULATION
---------------------------------------------------------- Chapter 1:2
Three federal agencies play a role in ensuring the safety of cellular
telephones by sharing responsibility for regulating devices that emit
radio-frequency radiation and protecting the public from exposure to
radiation: the Food and Drug Administration (FDA), the Environmental
Protection Agency (EPA), and the Federal Communications Commission
(FCC).
Under the Radiation Control for Health and Safety Act of 1968, as
amended, FDA is responsible for establishing and carrying out a
program, designed to protect public health and safety, to control
radiation from electronic products. These responsibilities include
(1) developing and administering performance standards for electronic
products; (2) planning, conducting, coordinating, and supporting
research, development, training, and operational activities to
minimize the emissions of, and exposure of people to, unnecessary
radiation from electronic products; and (3) developing, testing, and
evaluating the effectiveness of procedures and techniques for
minimizing exposure to electronic product radiation. FDA has the
authority to set performance standards for electronic products if it
determines that such standards are necessary for the public health
and safety. In carrying out its responsibilities, FDA reviews and
comments on industry research and also works with electronic product
manufacturers when it receives complaints or has some concerns about
a product but lacks sufficient scientific evidence to determine if a
performance standard is necessary. Consistent with the principle of
keeping exposure "as low as reasonably achievable," FDA has worked
with a variety of manufacturers to reduce radiation emissions. For
example, FDA has worked with manufacturers of video display terminals
and police radar devices to address concerns about excessive exposure
to radiation and with manufacturers of electric blankets to redesign
the blankets to reduce electric and magnetic fields.
Under the Federal Radiation Council Authority, transferred to EPA by
Reorganization Plan No. 3 of 1970, EPA is responsible for, among
other things, advising the President on radiation matters, including
providing guidance for all federal agencies on formulating protective
standards on radiation exposure. Upon presidential approval of EPA's
recommendation on formulating standards, the pertinent federal
agencies would be responsible for implementing the guidance. Under
the National Environmental Policy Act of 1969 (NEPA), FCC is required
to consider whether its actions--including actions that may lead to
human exposure to radio-frequency radiation--in authorizing
communications equipment significantly affect the quality of the
human environment.
OBJECTIVES, SCOPE, AND
METHODOLOGY
---------------------------------------------------------- Chapter 1:3
The Chairman of the Subcommittee on Telecommunications and Finance,
House Committee on Energy and Commerce, requested that we review (1)
the status of scientific knowledge on the potential health risks of
radio-frequency radiation emitted by portable cellular telephones and
federal involvement in any related research and (2) the actions of
the responsible federal agencies to ensure the safety of portable
cellular telephones and similar communications devices.
To assess the status of scientific knowledge on the health risks of
portable cellular telephone use, we met with scientists who have
conducted research on cellular telephones and visited industry,
university, and government laboratories where research is taking
place. We met with scientists and researchers in the field of
electromagnetic radiation at the Department of Defense, EPA, FCC,
FDA, and the National Academy of Sciences. (See app. II for a list
of the researchers and scientists we consulted for this report.) We
also obtained the opinions of many federal agencies with
representation on the Committee on Interagency Radiation Research and
Policy Coordination within the Executive Office of the President.\5
We discussed the safety of portable cellular telephones with the
president of the Bioelectromagnetics Society; the co-chairs of a
subcommittee established by the Institute of Electrical and
Electronics Engineers, Inc., which set the latest exposure standard
for radio-frequency radiation exposure; and a vice-president of
Motorola, Inc., a leader in cellular telephone research. In
addition, we met with officials from the National Council on
Radiation Protection and Measurements and the Cellular
Telecommunications Industry Association.
We collected information on regulatory actions regarding the safety
of portable cellular telephones from the responsible federal
agencies. We discussed with FCC officials the actions they have
taken to ensure the safe use of cellular telephones. We examined
FCC's records and rulemakings on the agency's process for authorizing
portable cellular telephones and FCC's implementation of requirements
under NEPA. We discussed with FDA officials their procedures for
setting performance standards for electronic products and their plans
for cellular telephones. Finally, we discussed with EPA officials,
and reviewed documents on, EPA's efforts to develop federal guidance
for setting standards for human exposure to radio-frequency
radiation. We conducted our review between March 1993 and October
1994 in accordance with generally accepted government auditing
standards.
--------------------
\5 The Committee on Interagency Radiation Research and Policy
Coordination, made up of representatives from 18 federal agencies,
acts as a coordinator and evaluator of the federal research effort on
radiation issues. It also coordinates radiation policy among
agencies, resolves policy conflicts, and advises on the formulation
of broad radiation policy. At the time of this report, the
committee's technical adviser told us that the committee had not
evaluated federal research needs for radio-frequency radiation (which
is non-ionizing radiation) but instead has focused on ionizing
radiation from sources such as nuclear energy.
EXISTING DATA ON EXPOSURE TO
LOW-LEVEL RADIO- FREQUENCY
RADIATION ARE INCONCLUSIVE
============================================================ Chapter 2
To date, neither the federal government nor the telecommunications
industry has completed any studies to determine specifically if the
use of portable cellular telephones poses health risks. While a few
recent studies suggest that long-term exposure to low levels of
radio-frequency radiation (similar to that emitted by portable
cellular telephones) may prompt interactions within and among cells
and organs that could possibly lead to adverse effects, other studies
do not. FDA and EPA agree that the research completed to date is
insufficient to determine whether using portable cellular telephones
presents risks to human health.
AVAILABLE SCIENTIFIC DATA ARE
INSUFFICIENT TO ASSESS HEALTH
RISKS OF CELLULAR TELEPHONES
---------------------------------------------------------- Chapter 2:1
The two basic sources of evidence of the relationship between a
potential risk factor, such as exposure to radio-frequency radiation,
and a disease are epidemiological studies (statistical studies that
relate the occurrence of a disease to the characteristics of people
and their environment) and laboratory studies on animals and
biological tissue samples. According to FDA and the National Science
Foundation, both types of research are needed to determine whether
cellular telephone use poses any health risks.
To date, no epidemiological studies have been conducted of human
exposure to radio-frequency radiation as a result of using cellular
telephones. Some recent biological and behavioral laboratory studies
on animals and cell samples have provided information on the
potential health effects posed by low-level exposure to
radio-frequency radiation, although none has examined radiation
exposure specifically from cellular telephones. FDA has questioned
the interpretation, significance, or applicability of the studies'
findings to cellular telephones. According to EPA, the significance
of recent research suggesting a potential for adverse health effects
cannot be determined until these studies have been independently
confirmed. Because of the limitations of the research, FDA and EPA
agree that more research would be necessary to determine whether
portable cellular telephones pose a human health risk.
The following are examples of some research results that scientists
say have raised questions about exposure to low-level radiation
similar to that emitted by portable cellular telephones, especially
pulse-modulated radiation, which is comparable to digital signals.
(See app. III for more information about some of these studies and
app. IV for a list of other relevant studies.)
A University of Washington study found that rats had difficulty
learning a maze exercise after 45 minutes of exposure to low-level,
pulsed radio-frequency radiation near the frequencies that personal
communications devices will use.\6 The researchers concluded that
exposure to low-power radio-frequency radiation appears to decrease
certain chemical agents in the rodents' central nervous system
essential for spatial learning.
In a 1983 study of cells from the immune system,\7 the researchers
found that the effectiveness of certain immune system cells in
fighting off tumor cells was temporarily diminished after only 4
hours of exposure to low-power, pulsed radio-frequency radio signals.
The researchers found that the effectiveness of the immune system
cells was diminished most when the radio-frequency radiation was
pulse-modulated 60 times per second, slightly more than the 50 times
per second that digital cellular telephone signals "pulse." (See app.
I for information on digital signals.)
In a 1991 study,\8 the researchers found that low-power
radio-frequency radiation may facilitate the development of cancer in
the presence of other substances known to cause cancer. They found
that when cells were exposed for 24 hours to low-level, pulsed
radio-frequency radiation alone, there was no effect on the cells'
survival or transformation into tumor cells. However, when the cells
were treated with a tumor-promoting chemical, exposure to
radio-frequency radiation significantly enhanced the transformation
of the cells into tumor cells.
Although these and a few other studies suggest that exposure to low
levels of radio-frequency radiation may cause effects in animals and
certain cell systems, other studies do not. For example, in a 1993
study, researchers injected brain tumor cells into rats and exposed
them to low levels of radio-frequency radiation--near the frequency
that cellular telephones use--that was either continuous (as in
analog technology) or pulsed 50 times per second (as in digital
technology).\9 The rats were exposed for 5 days a week until clinical
signs of tumor development occurred. Researchers found no evidence
that radio-frequency radiation treatment altered the course of tumor
development in the rats.
--------------------
\6 H. Lai, A. Horita, and A. W. Guy, "Neural Mechanisms Involved
in Microwave-Induced Deficit in Radial-Arm Maze Performance,"
Department of Pharmacology and Center for Bioengineering, University
of Washington, Seattle, Wash. (presented at the Bioelectromagnetics
Society meeting, Feb. 1993).
\7 D. B. Lyle, P. Schechter, W. R. Adey, and R. L. Lundak,
"Suppression of T-Lymphocyte Cytotoxicity Following Exposure to
Sinusoidally Amplitude-Modulated Fields," Bioelectromagnetics,
4:281-292 (1983).
\8 E. K. Balcer-Kubiczek and G. H. Harrison, "Neoplastic
Transformation of C3H/10T-1/2 Cells following Exposure to 120-Hz
Modulated 2.45-GHz Microwaves and Phorbol Ester Tumor Promoter,"
Radiation Research, 126:65-72 (1991).
\9 L. G. Salford, A. Brun, B. R. R. Persson, and J. Eberhardt,
"Experimental Studies of Brain Tumor Development During Exposure to
Continuous and Pulsed 915 MHz Radiofrequency Radiation," Biochemistry
and Bioenergetics, 30:313-318 (1993).
FEDERAL RESEARCH HAS BEEN
LIMITED
---------------------------------------------------------- Chapter 2:2
Several federal agencies sponsor radiation research, but none has
sponsored or performed any studies on portable cellular telephones.
Of 15 federal departments and agencies we contacted, only 4 had
conducted, funded, or planned research on radio-frequency radiation
that these agencies said may be relevant to questions about the
safety of cellular telephones. These four were FDA, the National
Institutes of Health's National Cancer Institute (NCI), the
Department of Commerce's National Institute of Standards and
Technology, and the Department of Defense. Only NCI has planned
research that specifically focuses on portable cellular telephone
use.
FOOD AND DRUG ADMINISTRATION
(FDA)
-------------------------------------------------------- Chapter 2:2.1
FDA is not performing or contracting for research specifically
addressing the power levels or frequencies of cellular telephones.
However, FDA officials said that some research the agency supports
may be relevant to safety questions about these telephones.
According to officials, FDA-supported research at the Johns Hopkins
Applied Physics Laboratory found that permanent damage occurred to
the eyes of test animals when the animals were exposed to low-level
microwave radiation. According to one of the researchers, this
effect was enhanced when the test animals were treated with drugs
commonly used in glaucoma treatment and exposed to radio-frequency
radiation at power levels several times lower than those typically
emitted by portable cellular telephones.
NATIONAL CANCER INSTITUTE
(NCI)
-------------------------------------------------------- Chapter 2:2.2
In 1993, NCI launched an epidemiological study to assess the
relationship between the use of cellular telephones, among other
variables, and the brain cancer newly diagnosed in 800 patients. An
NCI official expects this study to be completed between 1998 and
1999. In addition, NCI has planned other epidemiological studies to
determine whether (1) exposure to radio-frequency radiation, among
other possible risk factors, is associated with an increased risk of
brain tumors, and (2) the incidence of cancer can possibly be linked
with the use of portable cellular telephones. These studies involve
comparing the names on lists of cellular telephone users in New York
State with the names on New York's statewide cancer registry.
According to NCI, these studies should be initiated during 1995.
However, it is important to note that epidemiological studies do not
prove causality between two factors; they merely show that two
factors, such as exposure to radio-frequency radiation and a disease
such as cancer, tend to occur together.
NATIONAL INSTITUTE OF
STANDARDS AND TECHNOLOGY
(NIST)
-------------------------------------------------------- Chapter 2:2.3
In 1990, NIST measured the amount of radiation emitted by portable
police radios operated at frequencies near those used by portable
cellular telephones. NIST researchers found that the strength of the
electric fields emanating from the police radios exceeded the
exposure levels recommended as safe under the 1982 ANSI standard.
However, this study did not attempt to assess whether exposure to
these electric field emissions could present risks to human health.
DEPARTMENT OF DEFENSE (DOD)
-------------------------------------------------------- Chapter 2:2.4
DOD is sponsoring research into the biological effects of
radio-frequency radiation but not radiation from portable cellular
telephones. However, with the anticipated proliferation of new
telecommunications devices, DOD supports continued work to
characterize and measure the absorption and distribution of
radio-frequency energy in the human body. The Department's official
position is that harmful effects will not occur as a result of
exposure to portable cellular telephones as long as the amount of
radio-frequency energy absorbed by the human body is maintained at or
below permissible levels. DOD relies on the "permissible levels"
recommended by the 1982 ANSI standard, which states that devices
operating on 7 watts of power or less, like portable cellular
telephones, are not likely to exceed permissible levels.
INDUSTRY IS UNDERTAKING
RESEARCH ON SAFETY OF CELLULAR
TELEPHONES
---------------------------------------------------------- Chapter 2:3
We identified two major efforts by the cellular telephone industry to
specifically address the safety of portable cellular telephones: one
sponsored by Motorola, Inc., and one proposed by the Cellular
Telecommunications Industry Association (CTIA), a cellular telephone
industry association.
In 1991, Motorola, Inc., entered into a multiyear contract with a
researcher--considered by many in the scientific community to be the
most eminent U.S. researcher in this area--to conduct a series of
laboratory studies on radio-frequency radiation from portable
cellular telephones. These studies are examining the effects of
analog and digital signals from these telephones on animals and cells
but do not include studies of effects on humans. Results from the
animal studies are anticipated within the year.
In January 1993, in response to public concern that portable cellular
telephones may cause health risks, including brain cancer, CTIA
announced an initiative to spend from $15 million to $25 million over
the next 3 to 5 years to fund studies addressing the safety of
portable cellular telephones. In May 1993, CTIA, along with other
members of the cellular telephone industry, established a Science
Advisory Group on Cellular Telephone Safety. The science advisory
group's planned research agenda includes multidisciplinary studies
involving epidemiology, cell cultures, test animals, and genetic
research. The research will examine the effects of exposure to
analog and digital radio-frequency radiation at the power levels and
frequencies that cellular telephones use and that personal
communications devices will use. The research agenda also includes
scientific peer review of proposed research projects by a separate
board coordinated through the Harvard University Center for Risk
Analysis.
The chairman of the science advisory group also informed us that CTIA
funds the group's activities on a monthly basis; each month the
chairman submits an estimate of costs for the coming month, and CTIA
provides money for that month's research activities. The chairman
explained that the peer review board will evaluate and recommend
research proposals for funding. According to the chairman, payment
for peer review activities will be provided through a blind trust
established by the advisory group. The chairman stated that the
purpose of creating the blind trust for peer review was to provide
independence. However, the science advisory group does not enjoy
similar financial independence. The direct funding of the research
by CTIA raises questions about the objectivity and credibility of the
research effort. In September 1994, the chairman of the science
advisory group told us that CTIA would consider giving up direct
financial control by putting the research funds into a blind trust
fund.
In September 1993, FDA told the chairman of the science advisory
group that the agency would like to provide appropriate support
within its means to assist in ensuring that the industry-sponsored
research program was successful and credible. As a regulatory
agency, FDA considers that reviewing research data and commenting on
it is part of its job. However, the agency is reluctant to endorse
research that is not yet completed resulting from programs it has not
helped direct. Although the science advisory group has sought input
from federal agencies and has had informal discussions with officials
at FDA and EPA, no mechanism has been established for federal
participation in or comments on the research program. However, in
September 1994 the advisory group's chairman told us that he was open
to any role for federal agencies to increase the acceptance and
usefulness of the research program.
CONCLUSIONS
---------------------------------------------------------- Chapter 2:4
FDA and EPA believe that there is insufficient evidence to determine
whether exposure to low-level radio-frequency radiation presents a
human health risk. Some recent studies have found that this
radiation can produce biological effects. However, because none of
these studies examined radio-frequency radiation specifically from
portable cellular telephones, FDA and EPA agree that the value of the
studies' findings is limited in determining whether using portable
cellular telephones poses risks to human health.
FDA and National Science Foundation officials said that both
epidemiological and laboratory research are needed to determine
whether portable cellular telephones present risks to users. The
federal government and private industry are beginning to undertake
some of this needed research. NCI (the only federal agency
performing research on the safety of cellular telephones) has started
an epidemiological study to determine if there is a relationship
between cellular telephone use and cancer. But epidemiological
studies alone cannot conclusively establish whether using portable
cellular telephones poses health risks. Motorola is funding a series
of laboratory studies on the effects of radiation from portable
cellular telephones on animals and cells but no epidemiological
studies observing the effects on humans.
The cellular telephone industry is sponsoring a research initiative
through a science advisory board that includes both types of research
that federal officials say is needed. However, direct funding of
this research by CTIA--an industry association--raises questions
about the independence and objectivity of the science advisory
group's planned research program. The chairman of the science
advisory group has had informal discussions with federal agencies and
has expressed a willingness to accept a greater federal role to
increase the independence and objectivity of the research. Such a
role could also increase the usefulness of the research results to
federal regulators. To date, neither the science advisory group nor
any of the federal agencies have attempted to define what this role
might entail.
FEDERAL ACTIONS HAVE BEEN LIMITED
BY LACK OF EVIDENCE OF HEALTH
RISKS
============================================================ Chapter 3
Given the current state of scientific knowledge, FDA and EPA have not
had a basis for taking regulatory actions on portable cellular
telephones. However, FDA, EPA, and FCC are undertaking or
considering limited activities that could affect the use of such
telephones. FDA is working with cellular telephone manufacturers on
possible design changes for these telephones and improved
instructions for use. EPA is sponsoring a study on the status of
research on the effects of exposure to low levels of radio-frequency
radiation to determine if protective guidance is needed on exposure
to radiation from devices such as cellular telephones. FCC has
proposed adopting the revised ANSI standard in its environmental
rules and, as a result, may no longer exempt portable cellular
telephones from routine radiation evaluation.
FDA IS WORKING WITH CELLULAR
TELEPHONE MANUFACTURERS TO
MINIMIZE EXPOSURE TO RADIATION
---------------------------------------------------------- Chapter 3:1
An FDA official told us that FDA has primary responsibility for
responding if communications devices, such as portable cellular
telephones, pose a health risk. Although FDA says there is no
evidence that cellular telephones are harmful, an FDA official stated
that recent research on exposure to low-level radio-frequency
radiation from other sources has the agency concerned about the
possible adverse health effects of this type of radiation. In
carrying out its responsibility for controlling public exposure to
radiation from electronic products, FDA follows the principle that
exposure to radiation should be kept to a level as low as can
reasonably be achieved.
In early 1993, following allegations about the safety of portable
cellular telephones, FDA met with the cellular telephone industry,
including industry associations and cellular telephone manufacturers.
The purpose of these meetings was to discuss potential problems and
their solutions. As a result of these meetings, cellular telephone
manufacturers agreed to examine all practical routes to reduce
exposure, including possibly redesigning the telephones and providing
users with adequate instructions for proper use. The goal of
redesigning these telephones would be to change the placement of the
antenna so that this source of radiation is farther from the user's
head. According to an FDA official, instructions for use should
include practical information on how users can limit their exposure.
Although the industry representatives who met with FDA agreed to set
up committees to work on these topics, as of October 1994, they had
not reported back to FDA on the status of their efforts. Meanwhile,
FDA says that if individuals are concerned about avoiding even
potential risks, they could consider holding lengthy conversations on
conventional telephones and reserving the hand-held cellular
telephones for shorter conversations or for situations in which
conventional telephones are not available.
FDA does not believe it is justified in setting performance standards
for cellular telephones at this time. The formal process for setting
performance standards for electronic products is time-consuming and
expensive, and FDA will not set them without clear scientific
evidence that an electronic product poses a hazard to human health.
FDA does not have such evidence for portable cellular telephones. In
addition, an FDA official stated that the agency has received no
reports through its complaint process of radiation injuries resulting
from the use of cellular telephones. FDA officials said that the
agency has invested its limited research resources into
higher-priority work, such as medical devices that expose individuals
to much higher levels of radio-frequency radiation than cellular
telephones.
EPA IS ASSESSING STATUS OF
SCIENTIFIC KNOWLEDGE ON
PROLONGED EXPOSURE TO THIS TYPE
OF RADIATION
---------------------------------------------------------- Chapter 3:2
EPA is responsible for advising the President on radiation matters,
including developing federal guidance on radiation protection that
can be used by other federal regulatory agencies. For example, FCC
could use such guidance in approving communications equipment and FDA
in determining if performance standards are needed for devices like
portable cellular telephones. EPA officials told us that the agency
expects to issue, by the end of 1994, recommended maximum permissible
levels of exposure to radio-frequency radiation to protect people
from immediate thermal effects. However, EPA officials also told us
that because research on exposure to lower levels of radio-frequency
radiation is inconclusive, the agency cannot issue any guidance for
these exposures. To gain a better understanding of the status of
research on the effects of long-term exposure to low levels of
radiation and future research needs, EPA has funded a 2-year study by
the National Council on Radiation Protection and Measurements, a
nonprofit corporation chartered by the Congress. EPA officials
expect this work to provide information that will be helpful for
understanding whether the agency needs to provide protective guidance
on exposure to low levels of radiation.
EPA's recent activities on radiation guidance followed a 1992 report
by the agency's Science Advisory Board. The board recommended that
EPA complete a process to provide guidance that it began in the late
1970s. As part of this process, EPA requested comments on four
alternative approaches for controlling public exposure to
radio-frequency radiation.\10 However, EPA discontinued its efforts
to issue guidance in 1988 when it did not obtain agreement from
federal agencies on which approach it should take.\11
--------------------
\10 Three of the alternatives were EPA's proposals for specific
exposure limits based on varying degrees of safety from thermal
effects. The fourth alternative called for EPA, in lieu of issuing
federal guidance, to provide information and technical assistance
programs to federal agencies, states, or industry.
\11 According to EPA, under this notice and comment procedure, it is
EPA's practice to recommend an alternative to the President as
proposed federal guidance only if all the federal agencies providing
comments agree on one of the proposed alternatives.
FCC DEPENDS ON OTHER AGENCIES
IN DEVELOPING HEALTH-RELATED
REGULATIONS
---------------------------------------------------------- Chapter 3:3
FCC is responsible for regulating cellular telephone service and
authorizing the equipment used in providing that service. NEPA
requires all federal agencies to consider whether their actions
significantly affect the human environment. In carrying out its
responsibilities under NEPA, FCC formulated environmental rules that
require the Commission to consider whether its actions--including
actions that may lead to human exposure to radio-frequency
radiation--significantly affect the quality of the human environment.
FCC does not consider itself a health agency with the expertise to
determine what levels of radiation exposure are unsafe. Instead, it
relies on health and radiation expertise found in other federal
agencies, such as FDA and EPA. According to an FCC official, FCC
considers FDA the principle agency responsible for determining the
health implications of using specific devices such as cellular
telephones and for issuing performance standards. Similarly, FCC
would prefer to rely on EPA for information on exposure to
radio-frequency radiation.
Because there are no federal guidelines on radiation exposure, in
1985 FCC incorporated the 1982 ANSI exposure standard into its
environmental rules. This standard applies to higher-powered
transmitting equipment, such as radio and television broadcast
towers, but excludes devices that operate on or below 7 watts of
power at frequencies below 1,000 MHz. FCC does not require routine
environmental evaluation of portable cellular telephones in
authorizing their use because they operate on less than 1 watt of
power. However, as a safeguard, FCC's rules permit any interested
party, including FCC, to move that the exempted equipment be required
to undergo environmental evaluation. Thus far, no such motion has
been made about portable cellular telephones. In addition, the
Commission considers portable cellular telephones safe under this
standard. (See app. V for more information on the evolution of
FCC's environmental rules and rules on cellular telephone service.)
In 1993, FCC proposed adopting the revised version of the ANSI
standard to update its environmental rules.\12
According to an FCC official, the revised version is more stringent
than the older version, and, for the first time since FCC began
regulating cellular telephone service, portable cellular telephones
could be subject to environmental evaluation. Until this new
standard is adopted, cellular telephones will continue to be excluded
from routine environmental evaluation for public exposure to
radiation. In contrast, FCC has already decided that it will require
certain emerging hand-held personal communications services devices
to comply with the revised ANSI standard, pending its adoption of
this standard in its environmental rules.\13
--------------------
\12 In 1991 the Institute of Electrical and Electronics Engineers,
Inc., (IEEE) an engineering trade association, revised the 1982 ANSI
standard to reflect scientific research principally completed through
1985. The details of this standard are described in IEEE Standard
for Safety Levels with Respect to Human Exposure to Radio Frequency
Electromagnetic Fields, 3 kHz to 300 GHz, IEEE C95.1-1991 (revision
of ANSI C95.1-1982), Institute of Electrical and Electronics
Engineers, Inc. (1992).
\13 Hand-held personal communications services devices with (1) a
maximum input power to the antenna greater than 0.1 watts or (2) a
distance between the antenna and the user of less than 2.5
centimeters will be required to be evaluated for compliance with the
revised ANSI standard.
CONCLUSIONS
---------------------------------------------------------- Chapter 3:4
FDA, EPA, and FCC are undertaking limited activities that may affect
the use of portable cellular telephones. Without additional
scientific information, FDA and EPA have no basis for taking
regulatory actions. The federal and industry research discussed in
chapter 2 could provide information that would help these agencies
determine whether any regulatory actions are needed.
RECOMMENDATION
---------------------------------------------------------- Chapter 3:5
We recommend that the Commissioner of the Food and Drug
Administration and the Administrator of the Environmental Protection
Agency, in coordination with the Chairman of the Federal
Communications Commission, work with the industry's Science Advisory
Group on Cellular Telephone Safety to maximize the usefulness,
independence, and objectivity of its planned research initiative.
This effort could include participating in the selection of research
proposals to determine whether they meet federal research standards
and reviewing research results. This effort would be in addition to
ongoing and planned federal research.
AGENCY COMMENTS
---------------------------------------------------------- Chapter 3:6
As requested, we did not obtain written agency comments on a draft of
this report. However, we discussed the information in the report
with officials from FDA's Office of Science and Technology, including
the Chief of the Radiation Biology Branch; EPA's Office of Radiation
and Indoor Air, including the Electromagnetic Fields Team Leader in
the Radiation Studies Division; and FCC's Office of Engineering and
Technology, including the Chief Engineer. These officials generally
agreed that the information was accurate. The FDA and EPA officials
agreed that the current state of scientific knowledge is insufficient
to determine whether cellular telephones pose health risks. The
agencies assisted us in characterizing the scientific studies and
brought us up to date on their most recent activities related to
radio-frequency radiation exposure and cellular telephones. The FDA
and EPA officials said they plan to review the industry's completed
research.
We also asked officials from the National Cancer Institute's Division
of Cancer Etiology, the National Institute on Standards and
Technology's Management and Organization Division, and the Department
of Defense's Office of the Undersecretary of Defense for Acquisitions
and Technology to review the information in the sections of this
report pertaining to their agency. These officials generally agreed
that the information provided in this report was accurate, and we
incorporated their comments where appropriate.
ANALOG AND DIGITAL TRANSMISSION
SIGNALS
=========================================================== Appendix i
Some researchers have suggested that digital transmission signals,
under certain circumstances, may be more likely to produce nonthermal
effects with consequences for human health than analog signals.
Voice communications systems have traditionally relied on analog
signals to transmit messages. Using analog technology, voice
messages are electronically reproduced and amplified while being sent
to the receiver of the message. A problem with analog amplification
is that the voice message is imperfectly reproduced and tends to pick
up "noise" through amplification.
To reduce this noise in voice communications, engineers have
developed the technology to convert voice messages into
"digits"--that is, sound is converted into a pattern of 0's and 1's
representing the intensity of sound at points in time. Because the
digitized message is repeated exactly as it is transmitted to the
receiver, no additional noise is added. In addition to better sound
quality, digital technology affords more efficient use of
radio-frequency channels. When sound data are converted into digital
bits, information is more compact. Thus, capacity is added to the
radio waves over which the data are transmitted.
The cellular telephone industry's efforts to implement digital
technology have focused primarily on providing multiple access over
one frequency, or channel, by either (1) code division multiple
access (CDMA) or (2) time division multiple access (TDMA).
Under TDMA, several users share the same frequency, or channel, by
transmitting portions, or bursts, of data in short time intervals.
To do this, the signal is turned on and off 50 times per second,
causing the signal to appear to pulse.
Under CDMA, several users share the same frequency, or channel, at
the same time. Messages are transmitted digitally as various
sequences of 0's and 1's with a special code attached so that only
the intended receiver is able to decode the message.
Radiation researchers sometimes describe TDMA signals as
"pulse-modulated" or "extremely low frequency modulated"
radio-frequency radiation, meaning that a radio-frequency wave
carries a signal that varies 50 times per second.
RADIO-FREQUENCY RADIATION
RESEARCHERS AND SCIENTISTS
CONSULTED FOR THIS REPORT
========================================================== Appendix II
Eleanor Adair, Ph.D., Chair, Committee on Man and Radiation,
Institute of Electrical and Electronics Engineers, Inc.; Cochair,
Subcommittee IV on Safety Levels and/or Tolerances With Respect to
Personnel, Standards Coordinating Committee 28, Institute of
Electrical and Electronics Engineers, Inc.
W. Ross Adey, M.D., Associate Chief of Staff for Research and
Development, Veterans Administration Medical Center, Loma Linda,
California
Quirino Balzano, Ph.D., Vice President of the Technical Staff,
Motorola, Inc.
Howard I. Bassen, Center for Devices and Radiological Health, Food
and Drug Administration
George Carlo, Ph.D., J.D., Chair, Science Advisory Group, Cellular
Telecommunications Industry Association
Stephen F. Cleary, Ph.D., Department of Physiology and Biophysics,
Medical College of Virginia
Robert F. Cleveland, Jr., Ph.D., Office of Engineering and
Technology, Federal Communications Commission
Colonel Edward Elson, M.D., Department of Microwave Research, Walter
Reed Army Institute of Research
David N. Erwin, Ph.D., Chairman, Triservice Electromagnetic
Radiation Panel and Chief, Radiofrequency Radiation Division,
Armstrong Laboratory, Brooks Air Force Base
Om P. Gandhi, Sc.D., Chairman, Electrical Engineering Department,
University of Utah; Cochair, Subcommittee IV on Safety Levels and/or
Tolerances With Respect to Personnel, Standards Coordinating
Committee 28, Institute of Electrical and Electronics Engineers, Inc.
Arthur W. Guy, Ph.D., University of Washington (retired); Member,
National Council on Radiation Protection and Measurements
Henry A. Kues, Johns Hopkins University Applied Physics Laboratory
Henry Lai, Ph.D., University of Washington
Theodore A. Litovitz, Ph.D., Co-Director, Vitreous State Laboratory,
The Catholic University of America
Mary Ellen O'Connor, Ph.D., University of Tulsa; President,
Bioelectromagnetics Society
John M. Osepchuk, Ph.D., Member and Past Chair, Committee on Man and
Radiation, Institute of Electrical and Electronics Engineers, Inc.
Mays L. Swicord, Ph.D., Center for Devices and Radiological Health,
Food and Drug Administration
EXAMPLES OF RESEARCH INDICATING
BIOLOGICAL AND BEHAVIORAL EFFECTS
========================================================= Appendix III
Many scientists we consulted said that some recent research studies
have reported biological and behavioral effects as a result of
exposure to radio-frequency radiation. For example, a series of
laboratory studies have shown that exposure to radio-frequency
radiation may cause the release of calcium ions in the brain tissue
of live animals and in brain tissue samples.\14 According to the
Environmental Protection Agency, calcium ions play an essential role
in many cell processes, including the initiation of cell growth and
the promotion of tumors. However, no studies have shown that the
mobility of calcium ions induced by radio-frequency radiation poses a
health risk in humans.
In a 1990 study,\15 researchers exposed human tumor cells to 27
megahertz (MHz) and 2,450 MHz radio-frequency radiation at slightly
higher power levels than those used by portable cellular telephones.
(Personal communications services devices will transmit signals
between 1,850 and 2,200 MHz.) The researchers reported that the tumor
cells increased their uptake of the biological chemicals required for
cell reproduction after a single, 2-hour exposure to either 27 or
2,450 MHz radio-frequency radiation. Because the temperatures of the
cells did not increase during exposure, the researchers concluded
that the increased reproduction rate was not caused by heating. In
addition, the tumor cells continued to show signs of an increased
reproduction rate for up to 5 days after exposure, leading the
researchers to suggest that the effects of radio-frequency radiation
could possibly be cumulative when exposures occur at intervals of 5
days or less.
According to the experts we consulted, other recent studies suggest
that pulsed radio-frequency signals--similar to digital
signals--trigger biological events that could potentially lead to
adverse health effects. Reported findings include the (1) inhibition
of neurotransmitter activity, (2) suppression of immune responses,
and (3) copromotion of tumors.
Neurotransmitters are chemical agents that transmit information from
cell to cell within the nervous system. Certain neurotransmitters
are essential in the learning process. A University of Washington
study found that rats exposed to 1 milliwatt (mW)--much less power
than portable cellular telephones use--of pulsed 2,450 MHz
radio-frequency radiation for 45 minutes showed a deficit in their
ability to learn to perform in a radial-arm maze.\16 The study
concluded that exposure to low-power radio-frequency radiation
appears to decrease certain neurotransmitters in the central nervous
system involved in spatial learning in rodents.
The immune system is the physiological defense against a wide variety
of harmful agents, including bacteria, viruses, and tumors.
Specialized cells designed to kill abnormal cells form one line of
defense within the immune system. In a replicated study of the
responses of immune cells after exposure to radio-frequency
radiation, researchers found that the effectiveness of T-lymphocyte
cells (a type of natural "killer" cell) at fighting off tumor cells
was diminished after 4 hours of exposure to 1.5 mW of 450 MHz
radio-frequency radiation that was amplitude-modulated (or "pulsed")
at 3, 16, 40, 60, 80, and 100 times per second.\17 The killer cells'
effectiveness was diminished most when the radiation pulsed 60 times
per second. According to the scientists we consulted, this finding
is significant because digital cellular telephones, as well as
proposed personal communications devices, transmit signals at 50
bursts per second.
Some research is exploring the possibility that low-power
radio-frequency radiation may act as a copromoter of cancer in the
presence of known carcinogens. For example, in a 1991 study,\18
researchers exposed mouse embryo cells to low doses of 2,450 MHz
radio-frequency radiation pulsing 120 times per second for 24 hours.
Exposure to radiation alone had no effect on the cells' survival or
transformation into tumor cells. However, when the cells were
treated with a tumor-promoting chemical, the radiation exposure
significantly enhanced the transformation of the cells into tumor
cells.
According to the researchers and scientists we consulted, few data
are available to suggest that these triggering effects will occur in
humans under the exposures created by using portable cellular
telephones and the proposed personal communications services devices.
However, health and radiation experts told us that recent research
findings do raise questions about the potential health risks posed by
low-power radio-frequency radiation.
--------------------
\14 W. R. Adey, S. M. Bawin, and A. F. Lawrence, "Effects of
Weak Amplitude-Modulated Microwave Fields on Calcium Efflux from
Awake Cat Cerebral Cortex," Bioelectromagnetics, 3:295-307 (1982).
S.M. Bawin, L.K. Kaczmarek, and W. R. Adey, "Effects of Modulated
VHF Fields on the Central Nervous System," Annals of the N.Y.
Academy of Science, 247:74-81 (1975).
C. F. Blackman, J. A. Elder, C. M. Weil, S. G. Benane, D. C.
Eichinger, and D. E. House, "Induction of Calcium Ion Efflux from
Brain Tissue by Radiofrequency Radiation: Effects of Modulation
Frequency and Field Strength," Radio Science, 14(6S):93-98 (1979).
C. F. Blackman, S. G. Benane, J. A. Lampe, J. A. Elder, D.
E. House, and J. M. Faulk, "Induction of Calcium Ion Efflux from
Brain Tissue by Radiofrequency Radiation: Effect of Sample Number
and Modulation Frequency on the Power-Density Window,"
Bioelectromagnetics, 1:35-43 (1980).
C. F. Blackman, S. G. Benane, J. R. Rabinowitz, D. E. House,
and W. T. Joines, "A Role for the Magnetic Field in the
Radiation-Induced Efflux of Calcium Ions from Brain Tissue in Vitro,"
Bioelectromagnetics, 6:327-337 (1985).
C. F. Blackman, L. S. Kinney, D. E. House, and W. T. Joines,
"Multiple Power-Density Windows and Their Possible Origin,"
Bioelectromagnetics, 10:115-128 (1989).
S. K. Dutta, A. Subramoniam, B. Ghosh, and R. Parshad,
"Microwave Radiation-Induced Calcium Ion Efflux From Human
Neuroblastoma Cells in Culture," Bioelectromagnetics, 5:71-78 (1984).
\15 S. F. Cleary, L. M. Liu, and R. E. Merchant, "Glioma
Proliferation Modulated In Vitro by Isothermal Radiofrequency
Radiation Exposure," Radiation Research, 121:38-45 (1990).
\16 H. Lai, A. Horita, and A. W. Guy, "Neural Mechanisms Involved
in Microwave-Induced Deficit in Radial-Arm Maze Performance,"
Department of Pharmacology and Center for Bioengineering, University
of Washington, Seattle, Wash. (presented at the Bioelectromagnetics
Society meeting, Feb. 1993).
\17 D. B. Lyle, P. Schecter, W. R. Adey, and R. L. Lundak,
"Suppression of T-Lymphocyte Cytotoxicity Following Exposure to
Sinusoidally Amplitude-Modulated Fields," Bioelectromagnetics,
4:281-292 (1983).
\18 E. K. Balcer-Kubiczek and G. H. Harrison, "Neoplastic
Transformation of C3H/10T-1/2 Cells following Exposure to 120-Hz
Modulated 2.45-GHz Microwaves and Phorbol Ester Tumor Promoter,"
Radiation Research, 126:65-72 (1991).
SELECTED RESEARCH RELEVANT TO
HEALTH RISKS OF RADIO-FREQUENCY
RADIATION
========================================================== Appendix IV
The researchers and scientists we consulted cited the following
research studies as relevant to the biological effects of
radio-frequency radiation and the use of cellular telephones and the
proposed personal communications services devices. This compilation
is not all-inclusive.
Adey, W. R., S. M. Bawin, and A. F. Lawrence. "Effects of Weak
Amplitude-Modulated Microwave Fields on Calcium Efflux from Awake Cat
Cerebral Cortex." Bioelectromagnetics, 3:295-307 (1982).
Bawin, S. M., L. K. Kaczmarek, and W. R. Adey. "Effects of
Modulated VHF Fields on the Central Nervous System." Annals of the
N.Y. Academy of Science, 247:74-81 (1975).
Balcer-Kubiczek, E. K., and G. H. Harrison. "Evidence for
Microwave Carcinogenesis In Vitro." Carcinogenesis, 6:859-864 (1985).
_____. "Induction of Neoplastic Transformation in C3H/10T-1/2 Cells
by 2.45-GHz Microwaves and Phorbol Ester." Radiation Research,
117:531-537 (1989).
_____. "Neoplastic Transformation of C3H/10T-1/2 Cells Following
Exposure to 120-Hz Modulated 2.45-GHz Microwaves and Phorbol Ester
Tumor Promoter." Radiation Research, 126:65-72 (1991).
Blackman, C. F., J. A. Elder, C. M. Weil, S. G. Benane, D. C.
Eichinger, and D. E. House. "Induction of Calcium Ion Efflux from
Brain Tissue by Radiofrequency Radiation: Effects of Modulation
Frequency and Field Strength." Radio Science, 14(6S):93-98 (1979).
_____. S. G. Benane, J. A. Lampe, J. A. Elder, D. E. House,
and J. M. Faulk. "Induction of Calcium Ion Efflux from Brain
Tissue by Radiofrequency Radiation: Effect of Sample Number and
Modulation Frequency on the Power-Density Window."
Bioelectromagnetics, 1:35-43 (1980).
_____. S. G. Benane, J. R. Rabinowitz, D. E. House, and W. T.
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EVOLUTION OF FCC'S ENVIRONMENTAL
RULES
=========================================================== Appendix V
Table V.1 illustrates the chronology of key Federal Communications
Commission (FCC) rulemaking proceedings on the regulation of cellular
telephone service and the evolution of the Commission's environmental
rules to protect people from radio-frequency radiation.
Table V.1
Key FCC Actions on Regulation of
Cellular Service and Radio-Frequency
Radiation Safety Levels
Dat
e FCC action
--- ---------------------------------------------------------------------------
May Reserves the 806-947 MHz frequency band for land mobile service operations,
197 including cellular communications.
4
Sep Adopts rules complying with the National Environmental Policy Act, which
tem requires federal agencies to consider whether their major actions
ber significantly affect the human environment.
197
4
Jun Requests comments on its responsibility to consider the biological effects
e of radio-frequency radiation when authorizing devices.
197
9
Apr Allocates the 825-845 MHz and 870-890 MHz bands for cellular communications
il and implements rules governing cellular service.
198
1
Feb Amends its environmental rules by incorporating the 1982 ANSI standard for
rua radio-frequency radiation exposure (for lack of a federal standard or
ry guideline) that excludes devices operating on or below 7 watts of power,
198 such as cellular telephones, from compliance.
5
May Further amends its environmental rules by exempting certain categories of
198 its actions, including those on cellular telephone services, from routine
7 evaluation under its environmental rules.
Mar Proposes to update its environmental rules by incorporating the updated
ch version of the ANSI standard on exposure to radio-frequency radiation.
199
3
Jun Issues rules governing personal communications services that require
e manufacturers to ensure that certain equipment used in these services
199 complies with the revised ANSI standard that the Commission has proposed
4 incorporating into its environmental rules.
--------------------------------------------------------------------------------
Source: FCC.
As the table shows, FCC adopted environmental rules implementing the
National Environmental Policy Act of 1969 (NEPA) shortly after
reserving radio channels for cellular telephone service in 1974.
However, in developing its environmental rules, the Commission
concluded that only a few of its actions would significantly affect
the environment. Among such actions, for example, was authorizing
construction of communications and broadcast facilities, like antenna
towers, where damaging the physical environment could be a concern.
The operation of communications facilities, in FCC's opinion, would
have little or no effect on the environment. In the Report and Order
implementing its environmental rules, FCC states that
"[Communications facility operations] do not contribute in any
distinctive or significant way to air or water pollution. They do
not use hazardous substances, and . . . do not produce them."
FCC did acknowledge that electromagnetic radiation, such as radio
waves, can be hazardous. However, at the time the only known hazard
that radio-frequency radiation posed was biological damage from
heating at sufficiently high power levels. The Commission believed
that the only radio facilities with sufficient power to cause heat
damage were radio transmission facilities such as antenna towers.
Prompted by increased public awareness and concern over
radio-frequency radiation, in 1979 FCC began evaluating its
responsibilities to consider the biological effects of
radio-frequency radiation when authorizing equipment and issued a
Notice of Inquiry for comments from interested parties. On the basis
of comments received in response to this inquiry, FCC proposed in
1982 to amend its environmental rules by including an exposure
standard. This standard would trigger FCC's environmental assessment
process if equipment emitted radio-frequency radiation in excess of
the standard. However, no federal standard, or guideline, for
exposure to radio-frequency radiation existed, and FCC maintained
that it did not have the expertise to develop such a standard. Under
the Office of Management and Budget Circular A-119, federal agencies
may use voluntary industry standards in the absence of federal
standards. In 1985, FCC incorporated the 1982 ANSI standard into its
environmental rules.\19 This standard exempts devices that use 7
watts of power or less and operate at 1 gigahertz or lower, such as
cellular telephones, from complying with the standard's limits on
radiation exposures.
After adopting the ANSI standard, FCC exempted its decisions and
actions on cellular telephones from routine environmental evaluation.
According to an FCC official, because portable cellular telephones
operate on much less than 7 watts of power, the Commission considered
that these telephones would be safe on the basis of the ANSI
standard.
The ANSI standard was updated and revised in 1991, and in 1993 FCC
proposed adopting this revised standard to update its environmental
rules.\20 An FCC official told us that the revised standard is
stricter and that portable cellular telephones will probably be
subjected to environmental evaluation under the new standard. Until
this new standard is adopted, cellular telephones will continue to be
excluded from routine environmental evaluation for public exposure to
radiation.
In contrast, FCC has already decided that it will require certain
emerging hand-held personal communications services devices to comply
with the revised ANSI standard, pending its adoption of this standard
in its environmental rules. Hand-held personal communications
services devices with (1) a maximum input power to the antenna
greater than 0.1 watts or (2) a distance between the antenna and the
user of less than 2.5 centimeters will have to undergo evaluation for
compliance with the revised ANSI standard.
--------------------
\19 Safety Levels With Respect to Human Exposure to Radio Frequency
Electromagnetic Fields, 300 kHz to 100 GHz, ANSI C95.1-1982, the
American National Standards Institute, Inc. (1982).
\20 IEEE Standard for Safety Levels with Respect to Human Exposure to
Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz, IEEE
C95.1-1991 (Revision of ANSI C95.1-1982), the Institute of Electrical
and Electronics Engineers, Inc. (1992).
MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix VI
RESOURCES, COMMUNITY, AND ECONOMIC
DEVELOPMENT DIVISION, WASHINGTON,
D.C.
J. Erin Bozik
Barry T. Hill
Paul J. O'Neill
E. Jerry Seigler
Marnie S. Shaul
Phyllis Turner
OFFICE OF THE GENERAL COUNSEL
Mindi G. Weisenbloom
RELATED GAO PRODUCTS
Information Superhighway: Issues Affecting Development
(GAO/RCED-94-285, Sept. 30, 1994).
Electromagnetic Fields: Federal Efforts to Determine Health Effects
Are Behind Schedule (GAO/RCED-94-115, June 21, 1994).
Telecommunications: Concerns About Competition in the Cellular
Telephone Service Industry (GAO/RCED-92-220, July 1, 1992).
Efforts By The Environmental Protection Agency To Protect The Public
From Environmental Nonionizing Radiation Exposures (CED-78-79, Mar.
29, 1978).