1.0 INTRODUCTION
In recent years, the market for mobile telephone handsets and equipment has grown
astronomically, and many technologists predict continued expansion of this industry in
the future. This unprecedented growth has brought with it increased scrutiny, however, as
many are now worrying about the possible health risks of cellular phone use.
Many in the public and in government believe that the electromagnetic radiation emitted
by cellular phones could conceivably cause brain cancer or other long-term health
problems. This belief has opened up a brand new market for cellular phone radiation
shielding and compliance testing that has not yet been tapped. In this report we will
discuss whether mobile phone use is in fact linked to health problems, we will show how
the public has reacted to possible implications of such a cancer link, and we will suggest
how Resonant Microwave Technologies could profit from developing a product or
service that reduces health risks among mobile phone users.
We will begin by discussing some basic technical aspects of electromagnetic radiation
and cellular phones. We will then examine the results of several important scientific
studies that examine the link between mobile phone use and cancer. After that, we will
critique several current products that claim to shield cellular phone users from harmful
radiation, and we will evaluate Resonant Microwave Technologies’ interests in entering
the market of radiation shielding and compliance testing for mobile phones.
We hope that this report will provide a complete analysis of our topic and give a
sufficient amount of information for Resonant Microwave Technologies to make an
informed decision about our company’s interests in the cellular radiation prevention
market.
2.0 CELLULAR PHONES AND ELECTROMAGNETIC RADIATION
We will begin our discussion of the possible adverse health effects of cellular telephones
with a brief technical discussion of the physical entity that could be the root of such
effects, electromagnetic radiation (EMR). We will discuss electromagnetic waves, which
make up electromagnetic radiation, and give a brief discussion of the health issues
concerning these waves. We will recognize the important distinctions between ionizing
and non-ionizing radiation, and we will discuss how electromagnetic waves play a role in
cellular phone systems.
2.1 Biological Effects of Electromagnetic Waves dfggfdgd
Electromagnetic waves are made up of periodically
oscillating electric and magnetic fields moving
together through space. Figure 1 to the right gives a
representation of the waveform. A rapidly oscillating
voltage or current source can be used generate
electromagnetic waves [1]. Like all periodic waves,
electromagnetic waves have a specific frequency and Figure 1. Electromagnetic Wave [2]
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wavelength. The set of all frequencies that an electromagnetic wave can take on is called
the electromagnetic spectrum, shown in Figure 2 below.
Figure 2. The Electromagnetic Spectrum [2]
The electromagnetic spectrum covers an enormous range of frequencies. These
frequencies are expressed in cycles per second, or Hertz (Hz). The higher the frequency,
the shorter the distance between one wave and the next, and the greater the amount of
energy in the electromagnetic wave. High frequencies like X-rays cause ionization – the
breaking of molecular bonds, which damages genetic material. The well-known
biological effects of X-rays are associated with this ionization of molecules. At lower
frequencies, such as those characteristic of visible light, radio frequencies (RF), and
microwaves, the energy of the wave is very much below that needed to disrupt chemical
bonds. This part of the electromagnetic spectrum is termed non-ionizing. Because non-
ionizing electromagnetic energy cannot break chemical bonds there is no analogy
between the biological effects of ionizing and non-ionizing electromagnetic energy [2].
Non-ionizing radiation does have its own variety of biological effects, however. RF and
microwave sources can create biological effects by depositing the power of the
electromagnetic wave into cells and tissues, which causes heating. The level at which this
power is absorbed by a particular object is called the object’s specific absorption rate
(SAR); SARs are measured in watts/kilogram (W/kg). The number of SARs depends on
the frequency of the source, and the size and orientation of the object.
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2.2 Wireless Communication Systems and Mobile Phones
Modern wireless communication systems transmit information by varying an
electromagnetic wave in a regular, systematic way in order to represent the variations in
voice or data. This process of varying an electromagnetic wave is called wave
modulation. A system of modulation is analogous to a system of writing: when you write
you transform your ideas into a symbol through regular, systematic strokes of the pen.
Most systems of wireless communication involve adding the information-carrying
modulated wave on top of an existing sinusoidal wave called the carrier wave. The carrier
wave is analogous to a blank sheet of paper in a writing system, and the modulated wave
distorts the carrier wave as your pen marks the paper. The sender and receiver of the
information-carrying wave must agree on the frequency of the carrier wave and the way
in which information is to be modulated so that one can read the other’s message by
performing the inverse of the modulation operation, demodulation.
In a mobile phone system, strategically located base stations transmit and receive
modulated electromagnetic waves to and from mobile telephone handsets. The
information carried by the modulated wave is the content of the user’s conversation. Not
all the electromagnetic energy transmitted by the user’s cellular handset goes straight to
the base station, however. Much of it is absorbed by the surrounding air and, alas, the
user’s head. This is where possible cancer risks could originate.
2.3 Current Mobile Communication Systems
The major terms in the wireless industry such as “PCS,” “CDMA,” or “GSM” are names
for either different frequency ranges at which cellular systems operate or different
techniques of modulating the essential, information-carrying electromagnetic wave. To
avoid confusion later in the report, we will explain to you what each of these terms
means. First we will discuss the different frequency ranges and then the various
modulation techniques.
Most mobile phone systems operate at one of two standard frequency ranges somewhere
in the vicinity of 800-960 megahertz (MHz) and 1900-2200 MHz. In the U.S., the lower-
frequency range is classified as the “cellular” range, while the 1900 MHz range is
referred to as the “Personal Communication Services” (PCS) range. We will use the term
“cellular phone” in the remainder of this paper to refer to any kind of mobile phone, not
just those operating in the cellular range.
Mobile phone systems also make use of a number of wave-modulation systems. Old
mobile phone systems use analog modulation, while newer systems make use of digital
technology. In analog systems, the modulating wave varies continuously over time and
gradually changes from one output value to another. In digital systems, the modulating
wave changes rapidly and symbolizes the transmitted information in discrete chunks
rather than a smooth-flowing curve. The major digital modulation systems in use today
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are Code-Domain Multiple Access (CDMA), Time-Domain Multiple Access (TDMA),
and the Global System for Mobile Telecommunications (GSM). CDMA and TDMA are
common in the U.S., while GSM is the leading technology in Europe and worldwide.
We now turn our focus away from the technical aspects of electromagnetic radiation in
mobile phone systems, and concentrate on studies that have been conducted that try to
link this radiation to cancer or other health problems.
3.0 STUDIES LINKING CELLULAR TELEPHONES AND CANCER
Numerous studies have been conducted that try to connect cellular phone use with cancer
or other health problems. These studies use RF-exposure experiments on mice and other
animals, as well as milder tests on humans. Though little conclusive evidence of a link
between cell phones and cancer has in fact been found, the results of some of these
investigations have aroused a great deal of public concern.
3.1 Experiments on Animals
Many of the studies that try to link cell phones or RF radiation with cancer involve
testing on laboratory mice. The results of most of these studies are inconclusive, with one
notable exception. In a highly publicized investigation in 1997, Dr. Michael Repacholi,
current head of the World Health Organization (WHO), showed a correlation between
mice exposed to RF of the type used in cellular phones and increased incidence of
lymphoma, a kind of cancer. In this experiment Repacholi used mice that were already
prone to lymphoma since this condition is rare in normal mice. He exposed one group of
lymphoma-prone mice to a powerful RF source and left the other group as a control. The
mice exposed to radiation did in fact have greatly increased incidence of lymphoma,
showing a relationship between cancer and exposure to RF with the same frequency as
that emitted by cellular phones.
The Repacholi experiment drew much attention from the public, the telecommunications
industry, and legislatures around the world, though it actually raised more questions than
it answered. One big problem with the experiment is that a clear measure of how much
radiation (how many SARs) the mice were exposed to cannot be determined. The actual
power level used by the RF source in the experiment exceeded FCC standards, and the
position of the mice was not controlled as they were allowed to roam free in their cages.
Since specific absorption rate varies with distance to the source, the power level the mice
were exposed to varied greatly. For the Repacholi experiment to be taken seriously,
scientists must replicate it using normal mice, search for links to forms of cancer other
than lymphoma, and establish a clear relationship between the level of exposure and the
occurrence of cancer.
In addition to the Repacholi experiment, scientists have conducted at least ten other
major experiments using mice exposed to RF. The results of these experiments show no
strong relationship between low-level RF exposure and cancer. Two of the studies did
show a slight increase in the incidence of cancer in an exposed group of mice, but
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researchers have credited this increase to heating effects which would not be present
during the use of a cellular phone.
One other significant study involving animals measured the change in the death rate of
unborn chicks exposed to RF. In this study scientists placed 2-watt commercial cell
phones one centimeter away from eggs containing chick embryos and left another group
of eggs as a control. After 21 days, an increased mortality rate was seen among exposed
chicks. The results of this study could have been due to heating effects, however, and the
power level that the chicks were exposed to exceeds the 0.4 to 0.6 watts produced by U.S.
cellular and PCS phones.
3.2 Studies Involving Humans
In addition to directly measuring increased occurrence of cancer in laboratory animals,
scientists have looked for physiological changes that occur in humans as a result of low-
level RF exposure that might indicate some kind of link between cellular phone use and
cancer. Investigators have used experiments on human subjects and have conducted
surveys of cancer patients and cellular phone users to try to find a connection between
cell phones and health problems. Some provocative results have come out of these
studies, but many claim that these results are unscientific or inconclusive.
In one experiment, human subjects were asked to use a two-watt GSM phone for 35
minutes. After that period of time, scientists detected that the blood pressure of the
subjects had risen five to ten millimeters-of-mercury (mm Hg). The results of this
experiment are in question, however, because of the small number of subjects, and
because of the uncertain connection of blood pressure with real health issues. In another
experiment on humans, scientists connected electroencephalograph (EEG) leads to the
heads of subjects who then used cellular phones for an extended period of time. The
results of the experiment seem to show that cellular phone use alters the electrical activity
of the brain, but the scientists involved admit that this could be a false reading caused by
RF interference with the EEG leads. A similar study conducted in Helsinki found no
significant change in brain activity before and after mobile phone use [3].
Investigators also claim to have found a connection between cellular phone use and
headaches. In a Swedish and Norwegian study, researchers found that headaches
occurred more often among phone owners who used their phones more regularly. Those
who used their phones more than an hour each day also complained of increased warmth
sensations on their ear and burning sensations on their face and skin. In addition, analog
phones were found to result in more headaches than their digital GSM counterparts.
Many experts feel that the results of this study are unscientific because the evidence is
based on individual testimony and because no control group of non-users was included in
the study. They also claim that those who use their phones more often could have a
markedly different lifestyle than less frequent users, and that their lifestyle could lead to
more frequent headaches [4].
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3.3 Problems with Studies
One major problem involved in trying to conduct population studies correlating mobile
phone use and cancer rate is that phone technology is changing rapidly. Cellular phone
makers are already concerned about the possible cancer risks associated with their
products and are redesigning their handsets with more shielding and with backwards-
tilting antennas. Researchers say that this rapid change in technology has hindered their
ability to have adequate controls on large-scale population studies. This does, however,
show the high level of public and industry concern generated by previous studies of
cancer and cellular phones.
4.0 REACTION TO STUDIES
Though most scientific studies trying to link cellular phones and cancer have been
inconclusive, they have not ruled out such an association. This has prompted a wave of
hysteria that has manifested itself in action by government, industry, and the public.
4.1 Public Reaction
Following studies that failed to rule out a link between cellular phones and cancer, many
cellular phone owners sued phone manufacturers and wireless service carriers, claiming
that cell phone use played a role in their deteriorating health. In addition, at least one
community, the residents of Hardwick, Vermont, fought against cellular service carriers
locating base stations in their area. Hardwick’s residents were so vehement that FCC
Chairman Kennard and Vermont Senators Pat Leahy and James Jeffords convened a town
meeting to discuss the issue [5].
4.2 Government Reaction
To reduce the hazards of cellular phone use, strict governmental regulations of mobile
phone SARs exist in the U.S., in Europe, and in numerous other spots around the globe.
In the U.S., the Federal Communications Commission (FCC) sets limits of 1.6 W/kg for
mobile phones, while the European and international standard is 2 W/kg. Following the
recent focus of public attention on cellular phone safety, legislatures are funding more
research on this issue, are hotly debating whether safety measures need to be tightened,
and are prodding government agencies to develop new systems of compliance testing.
4.2.1 Support for further research. Since the studies that I have mentioned were
conducted, the European Union has approved a piece of legislation called the Fifth
Framework Program for Research and Technological Development, or FP5, which
allocates $179 million towards studies of “Environment and Health,” which includes
testing of cellular phone safety. This bill will pay for half of the approved cellular
safety research proposals, with the other half coming from industry [6].
4.2.2 The Sony Incident and Compliance Testing. A major incident involving
enforcement of government regulations on cell phone SARs occurred in December
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1998 when Sony announced that it would recall 60,000 cellular phones that were
found to exceed FCC limits. Customer service technicians discovered this problem
after the phones had already passed governmental compliance tests and had been put
on the market. The problem occurred in dual-mode phones, which operate either in
digital CDMA mode or in analog mode depending on what type of service is
available in the user’s area. Technicians detected the excessive SARs only in analog
mode. Sony argued to the FCC that the phones were only marginally above the SAR
limit and that recalling them was unnecessary, but the FCC responded that “An FCC
limit is like a speed limit – you can’t go above it.” Undoubtedly public concern
raised by studies relating mobile phones and cancer helped the FCC make its
decision.
The Sony incident prompted a firestorm within the FCC to standardize the system of
specific absorption rate compliance testing. The Institute of Electrical and Electronic
Engineers (IEEE) has a subcommittee known as SC-2 that is in charge of formalizing
these rules. FCC Chairman Kennard sent a letter to SC-2 following the Sony recall
requesting that they finish the compliance testing standards as soon as possible. Key
factors involved in testing are position of the phone, shape of the model head, and
the dielectric properties inside the model. One member of SC-2 was quoted as
saying, “The cost of recalling 60,000 phones is small compared to the cost of
planting a seed of doubt in the public mind. Something like this can happen only
because we still don’t have the proper engineering tools for compliance testing [7].”
4.2.3 Proposed legislation. In early 1998, the European Commission (EC)
recommended that the European Parliament adopt strict limits on electromagnetic
radiation exposure to the general public. This proposed legislation would replace the
patchwork system of regulations currently existing in member countries of the
European Union (EU). On February 18, 1999, the European Parliament rejected the
numerical limits presented in the EC report but agreed that a standardized system of
rules should be established based on the recommendations of the International
Commission on Non-ionizing Radiation Protection (ICNIRP). The guidelines set by
this commission are stricter than those currently in place in the U.S., but some
European ministers believe they are not strict enough [8].
4.3 Industry Reaction
In response to increasing public attention on the issue of cellular phones possible link to
health problems, many within the wireless industry are concentrating more on public
relations and marketing. German cellular phone manufacturer Hagenuk used public
awareness of this issue in a marketing ploy as it advertised that its handsets had very low
specific absorption rates. Hagenuk compared its phones’ SARs to those of other
European manufacturers, an action that started a trend of low-SAR phones in Europe.
Around the world, wireless industry trade associations have joined together to form the
World Information Network (WIN), designed to spread a positive image of the wireless
industry and to “share the techniques they find to be most effective in responding to
media inquiries and the public [9].”
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5.0 THE MARKET FOR MOBILE PHONE RADIATION REDUCTION
Despite the somewhat inconclusive results of studies trying to link cellular telephones
and cancer, the large public reaction to these studies started a trend within the wireless
industry for decreased radiation from mobile phones.
5.1 Existing Products
The idea of creating a product that shields mobile phone users from harmful radiation is
not a completely new idea. Several companies currently have products on the market that
are designed to reduce the possible health risks of cellular phones. We reviewed the
advertising and promotional material of a few of these companies in an attempt to gauge
what kind of competition and technology currently exists in this market.
The Angelite Cellular Phone Shield is one company that drew our attention. We reviewed
their internet advertisement, which lists a number of hazards related to cellular phone use
ranging from migraine headaches and gynecological problems to cancer. Angelite offers
no details of how their product works and no concrete evidence of its effectiveness. They
only claim that the shield reduces the risk of migraine headaches and brain cancer.
Additionally, at $60, the shield is almost as expensive as many new phones [10].
A company called Less EMF INC offers several other safety shields. The shields are
somewhat more affordable, ranging from $30 to $40, and aim to better quantify the
shields’ success in protecting your health. Nonetheless, these products suffer from a lack
of selection and ineffective advertising. Of the several products we investigated, all
concentrated exclusively on the Internet when advertising, thus eliminating a large sector
of cellular phone users [11].
5.2 Our Cost of Development
Having realized that there is much room for improvement in the radiation shielding
industry, our next obvious concern is how difficult it would be for Resonant Microwave
Technologies to begin development of a radiation shielding product for use with mobile
phones.
We are pleased to report that our company could begin development of such a product
with relative ease. Shielding foils are currently readily available for do-it-yourself
shielders. The cost of such foil starts at less than $15 per square foot and suppliers offer
significant discounts for buying in bulk. The foil, an 80% Nickel alloy, comes in various
thicknesses for a variety of applications and reduces electromagnetic power between 75%
and 95%. The availability of these raw materials would allow our company to begin
product development almost immediately [12].
Another way to offset the initial costs of development would be to market our services to
include compliance testing for phone manufacturers. In doing this, we would essentially
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be testing phones before they are shipped to the public to insure that they meet
government standards for specific absorption rates. It is obvious from the events
surrounding the Sony recall that companies would be interested in making sure their
phones meet FCC standards. Compliance testing could be done with the same machinery
used to test our shielding product, thereby allowing us to further profit from existing
machinery. Since all phones must be tested for SAR before being sold to the public, we
would be providing a service necessary to all phone manufactures while saving them
money on capital that they would otherwise not need to invest in.
5.3 Potential for Market Growth
The telecommunications industry has created a significant market for a mobile phone
radiation shield. Several current factors indicate that our product would enjoy great
success if introduced properly.
First, the current mobile phone market is very diverse. There are a number of different
phones currently available, all with different geometries and various shielding needs. We
could aim to provide shields for many types of phones, a strategy that no one has been
able to accomplish thus far.
More importantly, the cellular market is very dynamic. As mentioned earlier in our
report, the changing technology in mobile phones makes it difficult to study the effects
phones have on humans. We could capitalize on this problem by introducing a shield that
is so comprehensive that it makes all other shields obsolete, or we could continuously
update our product line, creating the need for a new shield periodically. Whatever the
case may be, we are left with several options that provide for our products’ success in the
future.
The exponential growth of the mobile phone industry could greatly benefit our plan for
subcontracting our services as compliance testers also. As long as mobile phones are
being produced, there will be a demand for our services.
5.4 Possible Marketing Strategies
Several reasons exist that indicate why current radiation shielding products have had
limited success. By better understanding these reasons, we can take the initial steps to
promote our products’ success.
5.4.1 Lack of current advertising. The shielding products currently available
suffer from ineffective advertising. The majority of advertising is being done on the
Internet, which fails to reach a large percentage of the available market. Through
increased public awareness, our product would naturally enjoy greater success.
5.4.2 Inability to harness public concern. The products currently on the market
have failed to take full advantage of the great amount of public concern that exists
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over the issue of mobile phones and cancer. In combination with an effective
advertising campaign, our company can take proactive steps to better understand
what the public wants and tailor our product accordingly. Surveying public opinion
would be an important initial step in accomplishing this task.
5.4.3 Failure to collaborate with phone manufacturers. One possible avenue to
insure success of our product or services would be to create partnerships with phone
manufacturers and help them in their quest to make phones safer. Due to recent
lawsuits filed against several manufacturers of phones, many companies might
welcome the opportunity to collaborate with Resonant Microwave Technologies and
subcontract shielding responsibilities to our company. We could then better enjoy
the success of the telecommunications industry because we would then be a direct
supplier for many already successful companies. The success of a compliance-
testing plan, for example, would be dependent upon collaboration with phone
manufacturers.
By better understanding the market for radiation shielding products and services and
realizing the necessary improvements for current products, Resonant Microwave
Technologies can better assess their prospective position in the industry.
6.0 CONCLUSION
After extensive research, we have found that little evidence actually exists to support the
claim that cellular phones cause cancer or any other long-term health risks. We have also
found that this fact has not stopped the public, the government, or the wireless industry
from panicking since the release of some provocative but inconclusive research that
merely failed to rule out a connection between cellular phones and cancer.
The trend for the future will be lower radiation phones, whether or not a link to cancer is
ever proven. The public would rather be safe then sorry. I believe that it is the best
interests of Resonant Microwave Technologies to enter the market for radiation shields
and cellular phone compliance testing.
Resonant Microwave Technologies has the resources necessary to effectively succeed in
the production of a mobile phone radiation-shielding device and provide the necessary
service of compliance testing for phone manufacturers. As a company, we could lower
the cost of similar products already in the market and take great strides in improving
advertising of these products. By making these improvements, our company could
potentially enjoy great success. This could propel us towards future profitability as we
gain a foothold in the burgeoning telecommunications industry.
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SOURCES
[1] “Electromagnetic Radiation,” in Encyclopedia Americana, 1991 ed.
[2] “J. Moulder, “Cellular Phone Antennas and Human Health,” Medical College of
Wisconsin, Dept. of Radiation Oncology, Version 2.1.0, Feb. 12, 1999.
[3] “Cellular Phones Pronounced Safe in Helsinki”, Microwave News, vol. 10, no. 1, pp.
1, 4-5, June 1997.
[4] “More Calls Mean More Headaches in Scandinavian Cell Phone Study”, Microwave
News, vol. 12, no. 2, pp. 4-6, Dec. 1997.
[5] “Wireless Notes”, Microwave News, vol. 19, no. 1, pp. 2, Jan./Feb., 1999.
[6] “European Health Research Effort Planned”, Microwave News, vol. 19, no. 1, pp. 2,
Jan./Feb. 1999.
[7] “Sony Recalls Mobile Phones That Exceed FCC RF/MW Limits”, Microwave News,
vol. 19, no. 1, pp. 1, 4-5, Jan./Feb. 1999.
[8] “European Parliament Debates Strict EMF–EMR exposure limits”, Microwave News,
vol. 19, no. 1, pp. 1, 9-10, Jan./Feb. 1999.
[9] “Industry Forms Global Group on Wireless Health Issues”, Microwave News, vol. 19,
no. 1, pp. 3-4, Jan./Feb. 1999.
[10] “Angelite Cellular Phone Shield,”
Accessed Apr. 5, 1999.
[11] “EMF Shielding Devices for Cell Phones,”
Accessed Apr. 5, 1999.
[12] “Magnetic Field Shielding Materials,”
Accessed Apr. 5, 1999.
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Fuente:
http://www.ece.utexas.edu/~denbina/project/final4.doc
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