According to recent statistics, breast cancer in
Australia effects one in 14 women, kills one in 27
and is increasing at a rate of 3% annually. These
figures reflect a growing community concern and as a
consequence, in 1995 the Federal Government allocated
$3 million over a 3 year period, solely for breast
cancer studies.
It is unfortunate however, that apparently no
current Australian breast cancer research is
examining the growing evidence that low level
exposures to 50-60 hertz electromagnetic fields (EMF)
may block melatonin's ability to suppress breast
cancer cells and reduce the pineal gland's nocturnal
production of melatonin, thereby increasing
susceptibility to breast cancer. This evidence
consists of both human and laboratory studies, some
of which are summarised in this paper. Almost all of
these studies have been conducted only within the
last few years and are still awaiting the peer review
process which can take years to complete. As a
result, many of these studies do not yet constitute
part of the body of substantiated scientific
evidence, often referred to by national and
international expert regulatory groups, such as the
International Commission on Non-Ionizing Radiation
Protection (ICNIRP).
In drafting its own guidelines for both
residential and occupational exposure to powerline
frequency (50-60 Hz) EMFs, Australian authorities,
such as the National Health & Medical Research
Council (NH&MRC) and the Australian Radiation
Laboratory (ARL) have taken their maximum exposure
guidelines from overseas expert groups, mainly the
ICNIRP, which are as follows, (for magnetic fields):
For Residential Exposures:
____ 1000 milliGauss (mG)
|
For Occupational Exposures:
____5000 milliGauss
|
This is the official position taken by Australian
regulatory bodies. However it is important to note
that these guidelines are only designed to avoid
immediate high level hazards and do not consider
prolonged low-level exposures at all. This was
admitted in 1991 by Dr Keith Lokan, from the ARL in a
conference paper published in Radiation Protection in
Australia (Vol 9 No.4, 1991), referring to IRPA/INIRC
guidelines which were taken over by the ICNIRP in
1993 and reconfirmed at that time.
To quote: " These limits [as above] represent
plausible field values, below which immediate adverse
health effects are unlikely, and as such serve a
useful purpose. They are NOT intended to provide
protection against possible cancer induction by
continued exposure at the lower field levels
implicated in the studies we have been considering at
this workshop." (1 - 3 mG)
So not only do the official guidelines fail to
consider low level exposures but the scientific
research they are based upon (substantiated evidence)
was last considered in 1993, when the current ICNIRP
guidelines were reconfirmed. This predates the entire
body of evidence as examined in this report.
The idea that low level powerline frequency
magnetic fields may reduce the pineal gland's
production of melatonin and that melatonin's ability
to suppress cancer cells is blocked by these fields,
is called the "melatonin hypothesis". At
the recent international conference, the Second World
Congress for Electricity and Magnetism in Biology and
Medicine , held in Bologna, Italy in June of 1997, it
is mentioned in the program bulletin:
"A number of experimental studies have been
conducted to test the [melatonin] hypothesis.
Although the literature is still evolving and
consensus is being built, it is fair to say, a) there
exists credible scientific support for the hypothesis
and, importantly, b) this support encompasses in
vitro, in vivo, and epidemiological research. The
melatonin hypothesis, thus, currently represents one
of the more well documented/tested interactions in
the field of bioelectromagnetics."
What is the medical fraternity to do when
presented with a significant body of reputable
scientific evidence that exposure to low level
powerline frequency magnetic fields may well be a
risk factor in breast cancer? Advice from such
government bodies such as the NH&MRC and the ARL
can only reflect their official position as mentioned
above.
Considering the prevalence of breast cancer in
Western society and the extensive body of recent
evidence pointing to a connection with EMF exposure,
it is the position of this report that with breast
cancer patients, avoiding excessive EMF exposure
should be part of the treatment, under the
Precautionary Principal, which in this case could be
defined as:
The precautionary principal should guide
decision-makers when confronted by potential threats
to human health. The lack of full scientific
certainty should not be used as a reason for
postponing measures to prevent exposure to these
potential threats. If measures generally reducing
exposure can be taken at reasonable expense and with
reasonable consequences in all other respects, an
effort should be made to reduce exposures to a level
below that level which evidence indicates may be
harmful to health
1.0: Melatonin
Both human and animal circadian rhythms are driven
by the day/night cycle and are synchronized with
natural geomagnetic electromagnetic fields. The major
control gland over this natural cycle is the pineal
gland which secretes the neurohormone melatonin.
During the day, light falling on the eye's retina
produces signals which are biochemically amplified to
stimulate the pineal gland to reduce its melatonin
output. At night the absence of light with sleep
stimulates the pineal gland to produce melatonin.
The circadian production of melatonin is thought
to control important processes in the eyes, including
restoration of rods (for night vision) at the end of
the night, and renewal of cones (for colour vision)
at the end of the day. One theory on how man made
EMF's may affect the pineal gland is that the pineal
gland may 'sense' EMF's as light and therefore reduce
melatonin production. A possible cause for such an
effect is from insoluble granular material contained
within the pineal gland.
Research by Dr. Sidney Lang, an expert on
piezoelectricity, which is the production of electric
fields by pressure on crystalline structures, has
shown that the pineal gland has piezoelectrical
activity. Dr Lang hypothesizes that this activity is
a function of this granular material and if so it may
be responding to narrow wave lenghts. (1)
Once melatonin is produced, its ability to pass
through the cell membrane allows it to pass directly
into the blood stream. Once in the blood melatonin
has access to every cell in the body where it passes
through the cell membrane to the cell nucleus, which
has receptors for it. A few cell membranes also have
receptors for melatonin, which may control the 24
hour circadian rhythm of the endocrine system.
In the cell nucleus, melatonin plays a role in
regulating gene expression. The ability of melatonin
to enter all cells is also essential for one of the
other important functions of melatonin, which is to
act as a scavenger of highly toxic oxygen-based free
radicals. The production of these free radicals is a
consequence of the utilization of oxygen by all
organisms. About 1 - 2% of inspired oxygen ends up as
toxic free radicals which can damage macromolecules
such as DNA, proteins and lipids. This damage is
referred to as oxidative stress.
Because of its ability to eliminate free radicals,
melatonin is probably the most efficient natural cell
protection and oncostatic agent in our bodies. At
night, melatonin production floods our bodies,
eliminating the build up of free radicals that are
being produced, allowing the DNA synthesis and cell
division to occur with a far lower chance of damage
and hence producing more healthy cells. Melatonin
also dampens the release of estrogen, prolonged
exposure to which may increase the risk of breast
cancer. ( 2 )
As for the role of melatonin in effective
chemotherapy, researchers at the Tumor Radiation
Laboratory at the University of Milan in Italy found
that elevated blood levels of melatonin significantly
enhanced the effectiveness of chemotherapy. The study
included 42 cancer patients of both sexes, including
10 breast cancer patients, 13 lung cancer patients,
and 11 colon cancer patients. It was found that 75%
(12 OF 16) patients whose melatonin levels were
enhanced after chemotherapy exhibited objectively
measured tumor regression, whereas only 8% (2 of 26
patients) whose melatonin levels did not go up after
chemotherapy exhibited tumor regression.
2.0: Tamoxifen
Tamoxifen, which is the most widely used therapy
for treatment of breast cancer, has proven effective
in treating breast cancer in its early stages and is
also used by over one million women throughout the
world who have had breast cancer, to prevent its
recurrence. Although tamoxifen is not as effective as
melatonin in inhibiting the growth of MCF-7 breast
cancer cells in vitro , the drug has been shown to be
about 100 times more effective in inhibiting breast
cancer cell growth if the cells have first been
pre-treated with a physio-logic concentration of
melatonin.
3.0:
Electromagnetic Fields (EMF)
In 1987 Stephens et al. in the paper, Electric
power use and breast cancer; a hypothesis, suggested
that electromagnetic fields (EMF's) reduce melatonin
production by the pineal gland and that melatonin
suppresses the development of breast cancer. ( 3 )
Other researchers have also hypothesized that the
possible suppression of melatonin by electromagnetic
fields may provide a single mechanism for explaining
how number of different types of cancer could be
promoted by EMF's, however this suggestion has been
hotly debated due to the previous failure to
replicate several key studies. Replication is a key
step in the scientific method for it takes an
unproven hypothesis to a significant conclusion which
can be acted upon.
In 1993 Dr David Blask and co-workers first
reported that physiological levels of melatonin
reduce MCF-7 human breast cancer cell growth in
vitro. ( 4 )
Research reported in 1993 by Liburdy, et al. found
that melatonin reduces the growth rate of human
breast cancer cells (MCF-7) in culture, but that a
12mG 60 Hz magnetic field can block the ability of
melatonin to inhibit breast cancer cell growth. ( 5 )
Examined in this report are five in vitro studies,
from three major laboratories, using human breast
cancer cell cultures, with results showing that low
level powerline frequency magnetic fields in the
order of 12 milligauss can block melatonin and/or
Tamoxifen's ability to suppress breast cancer cells.
It is this body of laboratory evidence and the
three human exposure studies also mentioned herein,
that have significant implications for the successful
treatment of breast cancer and calls for immediate
action from researchers and oncologists alike. The
failure to do so, under the excuse of "more
research needs to be done" is not acting in the
best interests of breast cancer patients, to say the
least.
In June 1996 at the 18 th. Annual Meeting of the
Bioelectro-magnetics Society (BEMS), the following
three studies were presented. When these three
studies are added to recent research presented at the
Second World Congress for Electricity and Magnetism
in Biology and Medicine, held in Bologna Italy, in
June of 1997, there now exists an important body of
scientific research in relation to breast cancer and
electromagnetic fields.
3.1: ELF INHIBITION OF MELA-TONIN AND TAMOXIFEN
ACTION ON MCF-7 CELL PROLIFER-ATION; FIELD
PARAMETERS.
(J.D. Harland and R.P. Liburdy. Lawrence
Berkeley National Laboratory, University of
California, Berkeley, California, USA.)
This study was designed to define the parameters
by which a 12 milli-Gauss (mG) 60 Hz magnetic field
can block the inhibitory action of melatonin and
Tamoxifen, a widely used drug treatment for breast
cancer. They found that a 12 mG field can
significantly reduce the growth inhibitory action of
melatonin and Tamoxifen on human breast cancer cells
(MCF-7) in culture.
"Preliminary experiments suggest that at
least three days exposure at 12mG is necessary to
block the cytostatic action of Tamoxifen (from 27%
growth inhibition, p<0.0001; to 5% growth
inhibition, p>0.5 ) indicating that prolonged 12mG
exposure may be required. This appears to be
consistent with a "slow"interaction
mechanism. This result also raises the possibility of
field effects that may be cell cycle dependent, since
measurable effects appear to be delayed or reversible
until cell division begins. In addition, all field
magnitudes of 12 mG or higher that have been tested
thus far (12mG, 20mG, 1Gauss) have been effective at
blocking melatonin." ( 6 )
A lower field of 2mG did not have any significant
effect, suggesting a threshold might exist between 2
and 12 mG.
3.2: INDEPENDENT REPLICATION OF
THE 12-MG. MAGNETIC FIELD EFFECT ON MELATONIN AND
MCF-7 CELLS IN VITRO.
C.F.Blackman, S.G. Benane, D.E. House and J.P.
Blanchard. National Health & Environmental
Effects Research Laboratory, U.S. Environmental
Protection Agency, USA.
This study was specifically designed to attempt to
replicate the previous study, with the cooperation of
the originating laboratory. The results independently
confirmed the previous study's findings that a)
Melatonin can inhibit the growth of human breast
cancer cells MCF-7 in culture, and b) A 12 mG 60 Hz
magnetic field can completely block melatonin's
oncostatic action.
The authors of this study believe these results
are particularly significant because these findings
represent the first replication of a key magnetic
bioeffect, and that these two studies represents a
foundation for theorists to generate
"testable" hypotheses for biological
mechanisms of interaction. (7)
3.3: INHIBITION OF MELATONIN'S
ACTION OF MCF-7 CELL PROLIFERATION BY MAGNETIC FIELDS
ASSOCIATED WITH VIDEO DISPLAY TERMINALS: A
PRELIMINARY STUDY.
(S.M.J. Afzal and R.P. Liburdy. Lawrence
Berkeley National Laboratory, University of
California, USA.)
This study was undertaken to test the hypothesis
that ELF and VLF magnetic fields associated with
Video Display Terminals (VDT's) influence human
breast cancer cell growth in vitro by altering
melatonin's natural oncostatic activity. This
hypothesis was based on the findings of the two
previously mentioned studies.
The conclusions of this study appear to suggest
that 12 mG VDT magnetic fields also inhibit the
oncostatic action of melatonin in vitro and that the
magnetic field component was the operative factor in
the 12 mG 60 Hz exposures. Preliminary data from two
seperate experiments indicated significant growth
inhibition (33% and 22%) on day 6 in the 2 mG
magnetic field conditions.( 8 )
A fourth study of a 12 mG effect on MCF-7 breast
cancer cells was presented at San Antonio Texas in
Nov.1996 by Dr Richard Luben, as follows:
3.4: REPLICATION OF 12 mG EMF
EFFECTS ON MELATONIN RESPONSES OF MCF-7 BREAST CANCER
CELLS IN VITRO. R.A.
(Luben, S. Saraiya and A. P. Morgan. Division
of Biomedical Sciences, University of California,
Riverside, California 92521, USA.)
The objective of this study was to replicate, with
the cooperation of the originating laboratories, the
studies conducted by Liburdy and Blackman.
They "found that exposure of breast cancer
cells to 12 mG 60 Hz EMF induced a reproductable net
increase (mean +28%, p<0.001) in the growth rate
of MCF-7 cells treated with a physiological dose of
melatonin. This constitutes a replication of the
observations reported previously by Liburdy and
Blackman, in that EMF produced a blocking of the
anti-cell-growth effects of melatonin. There are some
variations between our findings and theirs:
Nevertheless, the net differences between
(melatonin+EMF) and (melatonin-EMF) groups is both
qualitatively and quantitively consistent in all the
studies. . ." ( 9 )
From the Second World Congress for Electricity and
Magnetism in Biology and Medicine , held in Bologna,
Italy in June of 1997:
3.5: DIFFERENTIAL INHIBITION OF
TAMOXIFEN'S ONCOSTATIC FUNCTIONS IN A BREAST CANCER
CELL LINE BY A 12 mG MAGNETIC FIELD.
(J.D. Harland, M.Y. Lee, G.A. Levine, R.P.
Liburdy, Lawrence Berkeley National Laboratory,
University of California, USA.)
"Previously, we have reported that 12 mG (1.2
uT), 60-Hz magnetic fields reduce the inhibition of
tamoxifen's cytostatic action in the human mammary
tumor cell line MCF-7. tamoxifen is a nonsteroidal
antiestrogen, the most frequently prescribed drug for
the treatment of human estrogen-receptor (ER)
positive breast cancer, and known to bind
specifically to the estrogen receptor. However,
tamoxifen's action is multifactorial; besides its
oncostatic activities in ER+ cells, it also inhibits
the growth of some ER-breast cancer cells. The later
has been ascribed to tamoxifen's other cellular
activities In an effort to determine a possible site
of interaction of the 12 mG field with the cell, we
are investigating the effect of the 12 mG field on
the action of drugs known to differentially mimic one
of tamoxifen's cytostatic activities in MCF-7 cells
RESULTS: We observe a blocking effect of a
12 mG magnetic field of the pure antiestrogen ICI
182,780 This blocking effect appears to be even
greater than that seen for tamoxifen: from 18%
inhibition at 2 mG, to 15% enhancement of growth at
12 mG However we also find that the 12 mG field has
an even greater inhibition of the calmodulin
antagonist W-13, from 16% inhibition at 2 mG to 28%
enhancement of growth at 12 mG Future research will
be directed at further characterizing the specificity
of the 12 mG field interaction "(10)
4.0: Related
Research
Also at the Second World Congress for Electricity
and Magnetism in Biology and Medicine, held at
Bologna Italy in July 1997, R.P. Liburdy from the
Lawrence Berkeley National Laboratory, summed up the
current state of in vitro research findings:
"Collectively, this body of in vitro research
establishes that environmental-level 60-Hz magnetic
fields can alter melatonin's antiprolif-erative
activity in human breast cancer cells. The
significance of these findings is that a replicated
bioeffect involving melatonin has been identified
with the potential for elucidation possible
biological mechanisms. Moreover, the potential exists
for translation to relevant in vivo experiments
involving melatonin and environmental-level magnetic
fields."
It does not necessarily mean that the above in
vitro study conclusions can be directly applied to
breast cancer patients. However it is important to
note that some recent human exposure studies also
indicate a melatonim/EMF effect, and that levels
around 12 mG can be routinely encountered in daily
life, for example, electric blankets can give
emissions in excess of 12 mG, depending upon
manufacturer and setting used.
Sleeping with an electric blanket on is a special
concern, as it is at night that the pineal gland,
located near the centre of the brain, produces
melatonin. In the study by Liburdy and Harland,
indications were that a prolonged exposure may be
required, which is a further possible implication of
electric blanket use while sleeping.
In a study by Yaofei Liu and Dr. Indra Chatterjee
at the University of Nevada they found that with
electric blankets, "The average current density
(induced in the body) in the head is higher than the
torso because of the smaller cross section of the
head."( 11 )
4.1: At the June 1997
Bologna World Congress meeting, mentioned above, a
paper presented by the Faculty of Medicine,
University of Tokyo, specifically looked at melatonin
levels and electric blanket use. This study set out
to determine whether the effects of comparably
long-term powerline frequency EMF (from electric
blanket use) exposure on suppression of the melatonin
rhythm in humans could be replicated.
The participants were 9 healthy male volunteers,
23 to 37 years of age. The results of this study
found that: "Nocturnal exposures to 50 Hz EMF
generated from electric blankets was not related to
melatonin production in terms of its mean values (for
8 subjects excluding one whose rhythm could not be
calculated) but showed tendencies of suppressing peak
value and/or delaying phase of melatonin rhythm in 7
of the 8 subjects.
The present findings may suggest a possibility
that exposure to ELF-EMF by electric blankets, if
magnitude and duration are sufficient, could lead to
changes in melatonin production and its rhythm, at
least in highly sensitive individuals.
However, a definitive conclusion could not be
obtained from only the present results, since the
experiments were performed under unrestricted daily
lives. Experiments with major possible modifying
factors for melatonin metabolism being controlled are
warranted." (12)
It is important to note that the subjects of this
study were healthy young male volunteers, with
hopefully robust immune systems. What effect would be
seen with people who's immune systems are already
under stress, such as patients undergoing
chemotherapy?
In a soon to be published follow up study by Dr.
Henry Lai and Dr. Narendra Singh, who earlier found
single and double strand DNA breaks in rats exposed
to low level radiofrequency radiation (RFR) after a
single two hour exposure, the treatment of either
melatonin or a free radical scavenger (PBN) to the
exposed rats immediately before and after RFR
exposure prevented the DNA damage. (13)
This indicates the importance of melatonin in DNA
repair mechanisms, and therefore in cancer
suppression, but not that the RFR is effecting is the
rats own pineal melatonin production. The current
body of evidence examines Extremely Low Frequency
(ELF) 50-60 Hz fields and its effects on melatonin.
At this point in time evidence for a similar effect
on the pineal gland/ melatonin from radiofrequency
and microwave radiation has yet to be demonstrated.
(14)
In a study by Tan et al in 1993, rats were
injected with a chemical carcinogen, Safrole which
damages DNA by inducing the production of large
numbers of free radicals. Rats injected with Safrole
were found to have extensive DNA damage after 24
hours. When melatonin was also injected, the DNA
damage was reduced by 99%. (15)
4.2: A preliminary
study of 60 workers at a Finnish garment factory
found "a highly significant effect"of EMF's
in reducing nocturnal melatonin levels. Magnetic
field measurements were taken for the two types of
machines used in the factory and operators were
assigned to high or low exposure groups, based on the
type of machine they were using, with average
exposures either above of below 10 milliGauss.
Unexposed non industrial workers were used as
controls.
The results of this study found strong effects of
both magnetic field exposure and smoking on night
time levels of melatonin. No difference was found in
melatonin levels on week nights and Sunday nights,
indicating "that the possible suppression caused
by magnetic field exposure is chronic, with little
recovery during the weekend." (16 ) - consistent
with the effect of chronic electric field exposure in
the rat experiments of Wilson et al. (1986) ( 17 )
4.3: In a study of
192 electric utility workers, Drs. John Reif and
James Burch, from the Colorado State University,
found that some EMF exposures are associated with
lower levels of melatonin. They found a significant
association between magnetic field exposures and
lower daytime melatonin levels on the second and
third of three days of measurement. The lack of an
effect on the first day (following a weekend or
equivalent) may indicate a cumulative effect of
exposure.
Some studies have suggested that EMF effects on
melatonin may depend on whether the field is
continuous or intermittent. Reif and Burch found that
magnetic fields in the home that were
"temporally coherent"(less intermittent)
had a very significant association with lower
melatonin levels at night. They concluded that,
"The intensity and temporal characteristics of
magnetic fields appear to be involved in melatonin
suppression." ( 18 )
4.4: Office workers
who used computer monitors (VDU's) had a significant
reduction in circulating levels of melatonin over a
course of the working day, according to a study by
researchers Drs. Bengt Arnetz of the Karolinska
Institute, and Mats Berg of the Karolinska Hospital
in Stockholn Sweden. No such change was found during
days at the office with no VDU use. According to the
researchers; "This suggests that there is a
direct impact from the electromagnetic environment of
the VDU on levels of melatonin."
Levels of a different hormone, adrenocorticotropic
hormone (ACTH), went up during the working day and
this showed a strong correlation with worker's
subjective assessment of mental strain. Arnetz and
Berg note that ACTH is "known as a classic
stress hormone that reacts to mental strain."
But in contrast, "occupational strain did not
correlate with melatonin levels." ( 19 )
This finding supports the Boston University breast
cancer study, in which Patrica Coogan and co-workers
found a 43% increase in breast cancer among women
with a high potential for occupational exposures to
magnetic fields, notably those working with
main-frame computers. In an interview with Microwave
News , Coogan said,"This study lends credence to
the idea that EMF's might influence breast
cancer." ( 20 )
Not all human exposure studies found a melatonin
reduction effect. A study by Dr. Charles Graham et al
at the Midwest Research Laboratory in Kansas City,
MO. conducted for the Electric Power Research
Institute (EPRI), found that a continuous 60 Hz, 200
mG magnetic field applied to people while they slept
had no effect on nocturnal melatonin levels.
In a similar study published in 1994, Graham found
no overall effect for intermittent EMF exposures,
however, data from that study showed that men with
preexisting low levels of melatonin had even lower
levels when exposed to EMF's, suggesting that a
person's prior melatonin level may be an important
factor. Later research by Graham failed to replicate
this finding however.
Graham cautions against a conclusion that EMF's do
not effect melatonin. He points out that all of the
volunteers in his studies were "healthy young
men", and that the types of EMF's with which
people come in contact in an industrialised society
are much more varied than those created in the
carefully controlled MRI exposure facility. (21)
In relation to this, Dr John Reif of Colorado
State University comments, "Most natural
observations appear to find melatonin changes, while
controlled lab studies tend not to. . . In a general
way, I'm concerned that the controlled lab trials may
not mimic exposures in the real world."(22)
5.0: The
International Breast Cancer Intervention Study
This study, which has been running for five years
now, is aimed at discovering if the drug Tamox-ifen
can help prevent the disease in those who have not
yet developed it but are at increased risk.
Women from the UK, Europe, New Zealand and
Australia are participating in the study, which is
open to women aged between 35 and 70 who have a
strong family history of breast cancer.
Those aged 45 to 70 must have had a close family
member diagnosed with breast cancer at the age of 50
or under, or in both breasts at any age, or must have
two close blood relatives who have had breast cancer
at any age. Those aged 35 to 45 must have had a close
family member diagnosed with breast cancer before 40
or at least two close blood relatives who have had
breast cancer before 50.
Each participant is encouraged to continue with
the study for 5 years. During that time they take one
tablet, which is either Tamoxifen or a placebo, each
day and receive a clinical assessment every six
months and a mammogram each year. If Tamoxifen is
proved effective it could ultimately be provided to
women at increased risk.
Considering the above mentioned studies,
especially the study by Liburdy and Harland, ELF
Inhibition of Melatonin and Tamoxifen Action On MCF-7
Cell Proliferation; Field Parameters, which found
that a 12 mG magnetic field can significantly reduce
the growth inhibitory action of melatonin and
Tamoxifen, participants EMF exposures should be
included in the International Breast Cancer
Intervention Study as a possible confounding factor.
If EMF exposures are a possible confounding
factor, the statistical model for analysis of the
study should take into account this possible factor.
If not, the possible EMF factor may put enough
statistical noise to the study that the conclusions
may well be affected as the effectiveness of
Tamoxifen may be reduced in the participants with
relevant EMF exposures.
If environmental EMF's, and electric blanket use
are a confounding factor, this should be possible to
check by questioning the subjects on their habits,
maybe even taking home and workplace EMF exposure
readings. If some participants are found to be
exposed to prolonged EMF exposures in the order of 2
to 12 milliGauss, (there appears to be a
dose-response relationship from 2 to 12 milliGauss)
it may be advisable to recommend avoiding these
exposures. Since the studies examined in this paper
found no effect at 2 mG, this may be a safe level to
aim to keep prolonged exposures under.
It may also be advisable to do actual measurements
of melatonin levels in those subjects identified as
being prone to breast cancer. Women with breast
cancer have shown a lower nocturnal increase in
melatonin levels than control women. (23)
In the September 1996 issue of Epidemiology, Susan
Preston-Martin reviews much of the data on topic. She
also calls for including melatonin levels in breast
cancer risk assessment studies and for obtaining an
ELF exposure history.
A possible avenue for research would be to
determine if the use of melatonin would have a
similar protective effect as Tamoxifen, as breast
cancer patients may have a better prognosis if their
melatonin levels are high.(24)
Professor Russell Reiter who has been researching
the effects of EMF's on melatonin production has done
a review paper on this subject. This review paper was
prompted by a number of epidemiological studies in
which an increased incidence of cancer was reported
in individuals living or working in an environment of
higher than normal artificial electromagnetic fields.
His paper extract concludes with the following
observation:
"Reduction of melatonin at night, by any
means, increases cell's vulnerability to alteration
by carcinogenic agents. Thus, if in fact artificial
electromagnetic field exposure increases the
incidence of cancer in humans, a plausible mechanism
could involve a reduction in melatonin which is a
consequence of such exposures."
Dr. Reiter also notes: " Epidemiologists
should look for other possible changes, including
psychological depression, fatigue, sleep
inefficiency, chronic feelings of jet lag, endocrine
disturbances and other symptoms; all these may result
from a chronically low melatonin rhythm." ( 25 )
As a result of his latest study Dr. Reiter now
proposes that melatonin is "more rapidly taken
up into tissues during the exposure." He noted
that if EMF's result in higher levels of free
radicals, then an antioxidant like melatonin
"would disappear from the blood more quickly
than is normal because it would be required for the
scavenging of free radicals." (26)
If Reiter's hypothesis is correct, then prolonged
exposures may tax the pineal gland's ability to
maintain adequate levels of melatonin to cope with
the extra stress created by EMF exposure, and also
Tamoxifen's ability to inhibit the growth of breast
cancer cells.
6.0: World
Confer-ence on Breast Cancer on the U.S. National
Cancer Institute Linet Study
At The First World Conference On Breast Cancer,
held at Queens University, Kingston, Ontario, Canada,
from 13 to 17 July 1997, over 600 delegates from
around the world met to establish a Global Action
Plan to eradicate breast cancer, which currently
affects one in eight women in North America. This
plan will later be presented to the United Nations,
the World Health Organization and other major
international organizations.
As noted in the conference bulletin, the
conference was "a massive and truly global
undertaking, organized by grass-roots women's
organizations, survivors, environmental groups,
scientists and health-care professionals. For the
first time ever, the voices of the women and others
most affected by this disease will take centre stage,
as experts from around the globe assemble to share
knowledge and experience of this complex
problem."
Less than two weeks before the conference, the
U.S. National Cancer Institute released a study,
conducted by Dr. Martha Linet and co-workers, in
which it was claimed that there was no evidence that
powerline electromagnetic fields increase childhood
leukemia risks. This study was published on July 3rd
1997 in the New England Journal of Medicine and has
widely been mis-reported in the world's media as the
final word in exonerating powerline frequency EMFs
from any connection with cancer. This line is also
being promoted as proof that future research into
EMFs and cancer should cease.
The NCI study was specifically examined at the
conference and many concerns were raised on the calls
for ending future EMF health effects research, based
on the NCI Linet study. The following is a joint
press release on the NCI study from the conference:
Dateline: 1st World Conference on Breast Cancer,
Kingston, Ontario, Canada , July 15, 1997.
"The recent report in the New England Journal
of Medicine by Linet and colleagues has been widely
reported as showing no link between exposure to
electromagnetic fields (EMF) and one type of leukemia
in children.
On the basis of this new study, some scientists
and some news media organisations, including the
major networks, have repeated the questionable claim
that the link between EMF exposure and cancer risk is
no longer an issue, and further research is
unnecessary.
Such statements, based on a single study, are
troubling. More disturbing still, is the fact that
the data presented in the Linet study do not support
the assertion that no link exists. Even a cursory
review of the main data set shows a 53% increase in
leukemia incidence at magnetic field exposure levels
above 2 mG; a 72% increase (which is statistically
significant) above 3 mG; and a more than 600%
increase at exposures of between 4 and 5 mG.
Above 5 mG, no link is shown, but there are too
few cases in this range to yield any significant
result.
Dr. Bary Wilson, who has co-authored a recent book
on EMF and breast cancer, and several other speakers
at the World Conference on Breast Cancer, including
Dr. Kjell Hansson Mild of National Institute of
Working Life in Sweden, have stated that a study
which is apparently positive and limited only to
leukemia should not be used to discount a possible
link between EMF and cancer in its entirety.
Any statement claiming the demise of the EMF and
cancer issue should be based on an analysis of all
the available data and not one study, particularly
one in which the reported data are apparently not
reflected in the conclusions. In fact, available data
on the subject, provided by many scientists over more
than a decade, do not support the hypothesis that
there is no link between EMF exposure and increased
risk for several types of cancer.
Cindy Sage of Sage Associates and Chair of the EMF
program at the conference points out that, "even
a small increased risk of breast cancer due to EMF
exposure has enormous public health implications
given the high incidence of this disease in developed
countries."
Based on the Linet, et al. study, it is clearly
not justified to call for the end of research into
the possible !ink between EMF and cancer. Given the
growing body of evidence for a possible link between
EMF and breast cancer, in particular, cessation of
research funding at this time would be reckless and
scientifically indefensible."
Kjell Hansson Mild, Ph.D.
Natl lnst for Working Life, Sweden
Cindy Sage
Sage Associates, USA
Bary W. Wilson, Ph.D.
Pacific Northwest National Laboratory, USA
7.0: Conclusion
The evidence as outlined in this report, quite
clearly identifies commonly encountered environmental
magnetic fields of 12 milligauss, with a possible
dose-response relationship down to 2 milligauss, as
being a probable cancer promoter.
As to the role of cancer promoters, Dr. Robert
O.Becker in his book, Cross Currents states:
"Cancer promoters, however, have major
implications for the incidence of cancer because they
increase the number of cases of cancer that become
evident. We are constantly exposed to cancer-causing
agents in our environment ranging from carcinogenic
chemicals to cosmic rays.
As a result, we are always developing small
cancers that are recognised by our immune system and
destroyed. Any factor that increases the growth rate
of these small cancers gives them an advantage over
the immune system, as a result more people develop
clinical cancers that require treatment."
Therefore, it would be fair to say that in the
situation of residential and occupational exposures,
where cancer patients are routinely being exposed to
levels in the order of 12 mG, the necessity of
avoiding these exposures is paramount. Since the
recent World Conference on Breast Cancer, held in
Ontario Canada, there is an increasing overseas
awareness that EMFs are a risk factor with breast
cancer, but at present there are no figures as to the
degree of risk. In relation to breast cancer
patients, an important first step is to determine how
many are being exposed to EMFs of the order of 2 to
12 mG?
An important initial step would be to conduct
detailed surveys of groups of breast cancer patients
to build up a profile of any prolonged exposures in
relation to the 12 milligauss level. If we take 2 mG
as a no-effect level and 12 + mG as a definite level
of effect, we could get some idea of the percentage
of participants who are most likely at increased risk
from this exposure. Ideally such a survey would be
conducted independently in several countries, using
the same criteria and results then compared.
The outcome of this would be to develop effective
advice for patients to avoid exposures, which can
come from many sources, such as electric blankets,
electrically heated water beds, improperly grounded
home wiring, in-floor electrical heating systems,
older computer monitors, flourescent lighting
systems, occupational exposures, etc.
Although this paper only deals with powerline
EMFs, electromagnetic radiation (EMR) from
radiofrequency and microwave emissions are also now
being implicated in breast cancer.
Besides some epidemiological studies, such as one
showing a significant increase in breast cancer for
female radio operators, there is evidence that breast
cancer tumors absorb significantly more EMR than
other cancers, or healthy tissue. To quote from one
study, conducted at Duke University, North Carolina,
USA, in 1993.
"In general, at all frequencies tested [50 to
900 MHz], both conductivity and relative permittivity
were greater in malignant tissue than in normal
tissue of the same type. For tissues of the same
type, the differences in electrical properties from
normal to malignant were least for kidney (about 6%
and 4% average differences over the frequency range
in permittivity and conductivity, respectively), and
these differences were the greatest for mammary gland
(about 233% and 577% average differences in
permittivity and conductivity, respectively) (27)
The ability of breast cancer tumors to absorb
significantly more EMR than normal tissue should be
of concern when compared to an official joint
statement, made in the Information sheet, Safety of
Mobile Phones and Towers - The Answers (Nov.1995) by
the Australian Radiation Laboratory, Spectrum
Management Agency, Austel and the Commonwealth
Science and Industrial Research Organisation, (under
the heading, Is Cancer an issue?)
"There is yet insufficient scientific
knowledge of many aspects of health effects of radio
waves. One common question is: Do radio waves
frommobile phones increase the risks of cancer? The
answer is that there is no experimental evidence that
radio waves directly cause cancer. Laboratory studies
on animals suggest that where cancer exists, radio
waves may accelerate its growth."
For this reason, acting under the Precautionaly
Principal as mentioned prevously, one should also
consider radiofrequency and microwave exposures as a
possible risk factor to be avoided.
Don Maisch
Emfacts information Service
PO Box 96, North Hobart, Tasmania, 7002,
Australia
ph: (03) 6243 0195, Fax: (03) 6243 0340
e-mail:
emfacts@tassie.net.au
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27) Joines W.T., Zhang Y., Chenxing
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Copyright August 1997
