EMFs and Health - the history up to 2000
In recent years electromagnetic radiation has been implicated as a
contributory factor in a variety of adverse health effects. These range from
skin cancers due to exposure to increased levels of ultra-violet radiation from
the Sun because of the thinning of the ozone layer, through various childhood
and adult cancers (especially childhood leukaemia) due to power line magnetic
fields, to such things as cases of clinical depression and 'Cot deaths'.
Investigating 'man-made' EMFs
Initially most research was done investigating the effects of time-varying
electric fields, though in the last ten years the effort has concentrated on
power frequency magnetic fields. They are probably both involved in some, or
all, of the reported effects, and later in this chapter we look at some of the
suggested ways in which they can interact with our bodies.
Some extensive reports on the subject and detailed reviews of the literature
have been produced by such organisations as the U.S.A. Environmental Protection
Agency (EPA), the National Institute of Environmental Health Sciences (NIEHS),
the World Health Organisation (WHO), the U.K. National Radiological Protection
Board (NRPB) and the International Radiation Protection Association (IRPA).
There have been thousands of laboratory studies, both on isolated cells,
animals, and occasionally, people. These are primarily to try and identify
possible interactions and effects of electric and magnetic fields on living
systems, and to try to test hypotheses about how the effects could occur.
Both 'in vivo' (i.e. in the living organism) and 'in vitro' (e.g. in a
test-tube) studies have been done. Many of them have actually injected electric
currents using implanted electrodes, or used simplistic magnetic fields. Given
the latest ideas as to possible mechanisms of interaction, it is unlikely that
those studies will be able to tell us much about real life EMF-life
interactions. Many of the magnetic field experiments, assuming that the larger
the field the greater the effect, used fields considerably above the 300 nT
levels that are now being implicated by the field epidemiological studies.
Virtually none of them allowed for the background static geomagnetic field or
ac electric fields in the laboratory these could be the main reasons why it has
been so difficult to replicate and confirm the work in other laboratories.
The results are often confused and apparently contradictory, though this can
often be traced to the way the work has been planned and carried out. There are
so many different parameters which can affect the outcome of the experiments and
it seems that work is rarely repeated under exactly the same conditions.
Epidemiology is where the health of individuals in populations are studied in
order to try and identify possible causes of ill health. There are two main
types of study. The first, and the more common in EMF research, is the
case-control study, where the EMF exposure of people with a particular health
problem (cases) is compared with the exposure of similar people in similar
places without the same health problems. These have been used to study
headaches, depression & suicide, birth outcome, but mainly childhood
cancer. This is because it is (relatively) easy to study childhood cancer as the
medical records are quite good and children are not usually exposed to many
carcinogenic hazards.
The other main type of epidemiological study is the cohort study. This is
where the general health outcome of an exposed population is compared with
either a matched group (e.g. a similar village), or with the general
population's health record. Cohort studies tend to be more difficult to carry
out and analyse, although they offer the chance to pick up a variety of possible
adverse health effects. Very few residential EMF exposure cohort studies have
been done, although a number of occupational ones have.
There are hundreds of published studies, the results of many of which give us
cause for concern.
Extremely Low Frequency Studies
This includes power-line fields and ELF pulsed radio-frequency and microwave
signals.
Professor Ross Adey of the Loma Linda University Medical School in California
has been researching electrical bio-effects for over 35 years. He was previously
Director of the NASA Space Biology Institute, Professor of Anatomy &
Physiology UCLA, Founder UCLA Brain Research Institute, and a member of the
National Academy of Science Committee studying the bio- physical effects of the
Seafarer ELF Communication System.
Regarding the possible adverse health effects of ELF fields he stated in 1992:
"As far as the science itself goes, I think that there are four major
areas about which there can be very little doubt as to the significance of the
findings:
- The effects on the immune system. A reduction in the ability of the
circulating white blood cells to kill tumour cells. This has been shown in
cell culture work and partially corroborated in animal studies.
- Effects on fetal development. There is evidence not only of fetal
abnormalities but also in psycho-sexual development. Epidemio-logical work
has shown evidence that miscarriages may be linked to electrical blanket use
and some electrical home heating systems.
- The area of the control and regulation of cell growth, including
tumour formation.
- The effects on the central nervous system and the brain in the ways
which affect very powerful hormonal mechanisms, which in turn have
connections to cancer and cancer related problems.
The work is being conducted in many laboratories world-wide so that the
old fiction that this research describes uncorroborated experiments is no longer
true. The most significant finding is, I believe, although many of the effects
can be seen from the fields alone, they appear to be strongly synergic with
chemical factors. Some known chemical promoters are significantly enhanced in
their action by the presence of power-line frequency magnetic fields. This may
be a pointer to the clustering of cases, where there may be a common chemical
factor as well as the magnetic fields.
The chemicals which seem to be the problem are those which work on cell
membranes, and not on cell nuclei. The concept of cancer arising from damage to
DNA is now being supplanted by a different view of what the tumour problem
really is; that it is a problem at cell membranes where the electromagnetic
fields and these chemicals act together. I think that 'conclusive' is too strong
word to describe the evidence, but I think that the evidence is very strong that
there is this relationship. In consequence, as a matter of public policy, I
think what Granger Morgan at Carnegie Mellon University has suggested, namely
that Prudent Avoidance be part of Public Policy is a very necessary way to
tackle the problem. This implies not putting power lines over peoples' heads,
restricting the access of builders to vacant land next to high-voltage power
lines, and specific avoidance of school sites as a matter of public
responsibility.
I think that the British authorities' reaction is a living dinosaur
attitude, that it absolutely avoids confronting the evidence as it now exists.
The NRPB, however, is doing work of the highest merit in its scientific content,
and it indicates that there is reason to be concerned."[8]
The start of awareness about these issues
In the West the story really starts in the 1960s. Work in these areas has
often been funded directly or indirectly by the military or large firms with
vested interests. Controversial work is often classified, stopped, or planned in
ways which minimise the chances of detecting statistically significant risks. In
fact much of the initial informative work was done personally by the researchers
in their own time and with their own money. It is hardly surprising, then, that
official bodies can voice the criticism that the work hasn't been done on a
sufficient scale with sufficient controls. Let us consider some specific
examples.
Microwaves and eyes
In 1964 Dr. Milton Zaret was one of the first scientists to speak out about
the dangers of microwave radiation and ocular effects. According to Zaret,
exposure to EMF radiation at either thermal or non-thermal levels can cause
cataracts which sometimes remain latent for months or years. Zaret then had his
laboratory research funds cut off. "Now that's a very strong signal to everybody
else in the field" says Zaret in the 1984 Central TV documentary "The Good, the
Bad, and the Indefensible" [9].
Project Sanguine
One of the early bio-electromagnetics researchers is an author of two of the
books in our recommended reading list, Dr. Robert Becker [4][10]. He started
medical research work in 1947 and went on to become an eminent orthopaedic
surgeon and research scientist. He was twice nominated for a Nobel Prize for his
pioneering work on healing bone fractures and oedemas with externally applied
ELF electromagnetic fields.
In 1963 he also showed that there was a relationship between psychiatric
illness and magnetic storms. In 1973 he was appointed to a secret Navy civilian
advisory committee to assess the environmental impact of Project Sanguine, a
planned large scale ELF (45 & 70Hz) submarine communications system.
This committee was presented with a corpus of data generated by some twenty
or so programs run or funded by the U.S.Navy which contained enough data to
indicate that there were biological effects which were potentially hazardous to
human health. The frequencies were 45Hz and 75Hz and, after considering the
evidence, the committee unanimously felt that major segments of the American
population were "currently at risk" from 60Hz power-line fields, and went
on record to recommend that the White House be advised of the possible
significance of their findings.
Shortly afterwards Becker became aware of a plan to erect ten new high-power
lines in New York State, so he wrote to the N.Y. Public Service Commission to
suggest that they contact the Navy and get some details of the Sanguine studies.
He even provided a senior contact name and telephone number, but the Navy denied
that any such reports, or even the committee itself, existed! One of the chief
researchers for the Navy to whom Dr. Becker had been talking was Dr. Deitrich
Beischer at the U.S.Navy's Pensacola Research Labs. Becker tried again to
contact him and was told that the Labs. did not know of such a person. It was
subsequently shown that he had been prematurely retired and all his work in this
area classified. Dr. Beischer had been one of the U.S.Navy's principle
investigators since the late 1940's.
New York State Power Lines Project
The result of this was a lengthy series of public hearings, called the New
York State Power Lines Project (NYSPLP) at which Dr. Becker decided to testify,
which concluded with a five-year moratorium and a $5million series of studies.
The power companies, supported by the federal government, had an interest in
seeing that the hearings, if at all possible, did not take place, or if they
did, that the result cleared electromagnetic fields as providing no health
hazard. The line was given the go-ahead.
To quote Dr. Robert Becker subsequently: "Now it's impossible for me to
prove this, but the coincidences in time and place are too evident not to
believe that there was a relationship with this public hearing. Prior to my
involvement with this public hearing I was supported by several granting
agencies to do my research work. I had access to the scientific literature so
that my papers could get published in the appropriate journals. Following the
opening of the hearings we lost every research grant that we had. In addition we
were subject to administrative harassment by the agency for which I was
basically working, the United States Veterans Administration. The entire
circumstances were apparently designed to diminish my enthusiasm for proceeding
with these public hearings" [9]. Becker's crime was to establish a clear
link between power lines and health hazards. His punishment was scientific
exile. After some digging for information he discovered that pressure to remove
him had come from high up in the Department of Defence".
He writes: "I want to tell the public about it because it makes me
furious. I want the general public to know that science isn't run the way they
read about it in the newspapers and magazines. I want lay people to understand
that they cannot automatically accept scientists' pronouncements at face value,
for too often they're self-serving and misleading. The way science is currently
funded and evaluated, we are learning more and more about less and less, and
science is becoming our enemy instead of our friend."[10]
Wertheimer and Leeper
Around the same time (1974) Dr Nancy Wertheimer started working on her own,
using her own funds, to investigate childhood cancer clusters in Denver,
Colorado. She soon noticed that many seemed to be close to electrical
pole-mounted transformers. During the next few years she, and an physicist
friend Ed. Leeper, collected data and measurements. They eventually had their
paper published in the prestigious American Journal of Epidemiology in March
1979 [11]. Their work was ridiculed by the scientific and medical community who
said that there was no known mechanism by which such low levels of magnetic
fields could possibly affect human health. This attitude was supported by the
electricity utilities.
Some supportive evidence came from a Swedish study by Dr Lennart Tomenius
[12]. He started his work in 1979 and presented some preliminary findings at a
conference in June 1982, although his final Report was not published until 1986.
He had measured the fields at the entrance door to the residence of the
children, and found that for fields over 300 nT (3 mG) the chance of getting
cancer was more than doubled. For brain tumours the increase was almost
four-fold (Odds Ratio = 3.86).
The N.Y. State Power Line Project studies mentioned above include one by Dr
David Savitz. He announced his preliminary results in November 1986 which showed
"prolonged exposure to low-level power-frequency magnetic fields may
increase the risk of developing cancer in children". Indeed Savitz not only
found a statistically significant association between all types of childhood
cancer and external magnetic fields, but also determined that children living
close to high-current wiring had a five-fold increased risk of developing
cancer. His final Report was not published until 1988 [13]. This showed almost a
doubling (1.93) in childhood leukaemias at fields above 200 nT. Indeed the
1987 NYSPLP report points out the possibility that 10 to 15% of all childhood
cancer cases in the U.S.A. might be attributable to power frequency magnetic
fields of around 250 nT (2.5 mG) and above.
Some U.K. epidemiological studies
Before privatisation the U.K.'s Central Electricity Generating Board (CEGB)
sponsored two main studies.
The first, called "Overhead Power Lines and Childhood Cancer", done in
conjunction with the University of Leeds and Cockridge Hospital, Leeds, was
first published at an IEE meeting in December 1985 [14]. This is the only study
they have published following up the work of Nancy Wertheimer et al, and it has
very significant shortcomings. The Wertheimer and Tomenius studies are quoted as
the background to the Leeds study and so it would seem sensible to include some
areas where the background 50 Hz magnetic fields were likely to exceed 250 nT.
Looking at the data presented in the report we find that the magnetic fields
were only calculated by computer modelling of the overhead power lines, and were
not actually measured. This seems specifically to exclude locally generated
fields. Secondly, that out of the 376 case and 590 control children included in
the analysis, 361 cases and 567 controls were below 10 nT, a further 9 cases and
15 controls were in the range 10 nT to 100 nT, and only 6 cases and 8 controls
were in calculated fields above 100 nT.
If we take the one figure suggested that 15% of all childhood cancer cases
may be due to fields of 200 nT or above, and allow that the six cases were, in
fact, in fields over 200 nT, and that we had an ideal sample, then the
researchers were ONLY likely to have included 0.9 case in their
survey! The conclusion that "within the bounds of the present analysis,
there is no apparent relationship between overhead power lines and childhood
cancer" was therefore to be expected.
The CEGB Chief Medical Officer at the time, Dr John Bonnell, is on record as
saying: "At the present time I do not believe any action is justified. If we
accepted the dangers it would mean an enormous turn about for industry and for
the country as a whole. There are no contingency plans to cope with such a turn
about. If there are any effects at all due to exposure to electric fields then
they are slight, and it is certainly extremely difficult to disentangle them
from other causes of ill health."[9].
The above study has been repeatedly used to claim 'a clean bill of health'
for overhead power lines. The study was based around calculated fields from high
voltage power lines so as to exclude the effects of street and house wiring. In
other words, it was only designed to try and detect a link between childhood
cancer and high voltage power lines, rather than actual 50 Hz EM fields.
The C.E.G.B. sponsored U.K. studies assumed a very low background 50 Hz
magnetic field level of 10 nT, and only used calculated levels due to overhead
electrical lines at the birth addresses. National Grid now recognise that 60 nT
is a more typical background level, and measurements suggest that a significant
proportion of the U.K. population live in 50 Hz fields approaching or
exceeding 100 nT, with people living near high power feeds being subject to
fields up to 25 mT (25,000 nT).
In fact the study does comment on a sample of 44 properties, not otherwise
included in the study, where the house internal magnetic fields were measured.
The highest field of 130 nT was reported as being due to a neighbouring overhead
local power line and not a high voltage transmission line and so it would have
been assessed as having only a background field of 10 nT. This agrees with
typical levels measured by the author, Alasdair Philips, some details of which
are given in the next chapter. A 1990 CEGB paper [15] also supports the view
that local distribution cables are a major source of domestic magnetic fields.
This means that many houses which the study has assumed to have only background
levels may well have had quite high magnetic fields.
A second study [16] of adult leukaemia and allied diseases, covering
Yorkshire and part of Lancashire, suffered the same methodology, only using
magnetic fields calculated from high voltage transmission lines [17].
The childhood study was extended and re-analysed [18] and it was admitted
that: "This study stood no realistic chance of detecting any raised
relative risk associated with a field of more than 100 nT".
In January 1992, Dr. David Jeffers, speaking for National Grid, publicly
stated: "We have a number of strong players in this program. We have had what
you call epidemiological studies, carried out in Yorkshire, of how childhood
cancer correlates with the fields in the houses and how close the houses are to
power lines, and the answer was 'no', we did not find a correlation in
Yorkshire. A similar study of adult leukaemias, carried out in Yorkshire and
Lancashire, also did not find an association." [2]
It is difficult to see how these studies can be described as 'strong players',
other than as part of a planned "effort to put their fears to rest".
Some other epidemiological studies
One Swedish study by Feychting and Ahlbom [19] drew their subjects from
corridors of land beneath Sweden's network of high voltage pylon lines and they
found that between 1960 and 1985 around 500,000 people had lived within 300
metres of the lines.
They calculated that children younger than 15 were 2.7 times more likely to
contact leukaemia when exposed to magnetic fluxes greater that 200 nanotesla and
3.8 times when exposed to 300 nT. These figures agree very well with the earlier
Wertheimer and Savitz ones. The field levels are about 6,000 times less than the
current UK limit.
Further Nordic studies were published in 1993 and a combined analysis
supported the link between ELF magnetic fields and childhood leukaemia at field
levels above 200 to 300 nT [20].
There are a number of other studies which indicate other illnesses e.g.
headaches, depression, suicide, myalgias, asthenias, leucocyte count disturbance
leading to impaired immune response, etc.
An American study showed a statistically significant doubled elevation of
headache and depressive symptoms among populations living within sight of power
lines. Another study has shown up to a five-fold increase in risk of miscarriage
among women who use electric blankets [21], which is the fifth report to show
that EMFs can adversely affect pregnancy.
Initially when Dr. Stephen Perry started investigating the possible
relationship between power lines and suicides and clinical depression in the
West Midlands, the C.E.G.B and local Electricity Boards were extremely helpful
and provided copies of their maps showing the power lines. When he told them
that there were three times as many suicides as there should have been in the
urban roads that carried their heavy underground cables they stopped giving him
any more information. When the study was published it showed that people living
in high magnetic fields next to power lines were 40% more likely to commit
suicide [22].
Dr. Perry went on to do a second study of the distribution of illnes in
multi-story blocks of flats in Wolverhampton [23]. Here he found that in blocks
where there was underfloor or electric storage heating systems, the proportion
of cases of depressive illness living in the flats nearest to the main cable
duct rose to a highly (P = 0.013) significant 82% of cases of depressive illness
admitted to hospital from such blocks.
In a third paper [24] he investigated, in 1985, all the admissions to
hospital from Wolverhampton for myocardial infarct (600) and depressive illness
(359), with regard to the measured magnetic field levels at the patients
residential address. He found a significant (P=0.033) correlation between higher
magnetic field levels and cases of depressive illness, but not for myocardial
infarction.
Public money has not been forthcoming to replicate Dr. Perry's work on
depressive illness which, if the asscociations it found are real, point to a
much more significant public health problem than childhood leukaemia, which
although devastating for the people concerned, is actually quite rare. Dr. John
Dennis, while Assistant Director of the NRPB issued a statement in 1989 which
includes: "if the link is real then EM fields may be responsible for upto 15%
of all childhood cancers, but as childhood cancer is a comparatively rare
disease the increased risks, if real, are within the levels generally regarded
as acceptable."
ELF epidemiology conclusions
There have now been many ELF epidemiological studies published. Overall, the
results are varied and inconclusive, though the vast majority have shown
increased risks of ill health with increasing ELF EM field levels. In
particular, the childhood cancer studies have pointed fairly consistently
towards a two to three fold increase at levels of 200 to 300 nT. All the studies
can be criticised on the basis of low detection power and questionable surrogate
measures of exposure, which would give rise to a considerable under-estimate of
the level of risk.
In fact most of the studies have only calculated the magnetic fields from
high voltage transmission lines and assumed a relatively low ambient background
field in all other houses. Some have only directly used distance from these
lines and/or from substations. As we attempt to show in the next chapter,
firstly it is almost impossible to calculate the field with any degree of
accuracy with the available data and, secondly, the ambient field level in many
houses is dominated by the fields from local distribution cables and can be up
to 1000 nT, or more. It is surprising that, with these two sources of error
alone, that the studies have almost all shown small raised levels of risk, and
suggests that the real increase in risk with ELF EMFs is likely to be much higher.
Recently Dr. Nancy Wertheimer, the epidemiologist working in this field since
1974, made a number of comments about survey work [25]. She suggests that
because most studies have not checked that their control groups actually do live
in a low exposure situation, they are like those that compare people who smoke
2.5 packs of cigarettes a day to those who only smoke two packs. She goes on to
say that evidence suggests that the critical period is between one and two years
before diagnosis. Just using the birth address, as done in the U.K. study, will
therefore lead to invalid data.
Part of the reason for these limitations is that much of the work has only
been designed to see if there is an increased risk of childhood cancer with
proximity to high voltage power lines. In fact the real question, of whether
there is a relationship between ELF EM fields and adverse health effects, is not
really addressed in a meaningful way by these studies.
Confounding factors
Another, very puzzling, omission is that virtually no studies have measured
the relationship between the man-made fields and the Earth's geomagnetic field,
even though a number of the more likely resonance theories are based around
these inter-relationships. This seems most odd, because it is usual to start out
by designing a study methodology in order to investigate the validity, or
otherwise, of any of the suggested mechanisms of interaction. This is to try to
reduce the number of 'confounders', which are variables that are likely to
affect the phenomena that are being studied. Socio-economic class, housing
density, traffic density, cigarette smoking in the house, local climate, race,
etc., are typical examples of these. As the Earth's magnetic field strength and
direction in relation to the ELF fields are fundamental to the suggested
resonance mechanisms, it seems essential to collect this data.
It has been suggested that given the nature of the data (relatively few cases
in populations of varying size), that the "rate per thousand" is not the most
revealing method of ranking. In these cases it is often better to use the
Poisson probability. This tests the important question as to whether the
observed incidence in each community group can be explained by chance or by the
likelihood that the observed cases have a common cause. It is not evident that
this has been used in any of the published epidemiological studies.
Other health effects
The major studies have concentrated on cancers. In view of the fact that the
effects may well be due to a general lowering of the body's overall immune
competence, it would seem appropriate to carry out various cohort studies
looking at all health aspects of exposed population groups living under or near
large power lines, and comparing the data with that for similar populations
which are not near major EMF sources. It would be necessary to actually record
the fields in each study person's home with a data logger in order to get a good
exposure assessment. This would need to include the geomagnetic data discussed
above.
Such a study would also be able to follow up Dr Stephen Perry's work linking
power-line magnetic fields with clinical depression and suicide. The NRPB have
described this as interesting but having flawed methodology. For some reason
they have chosen not to encourage or sponsor a better study, although clinical
depression is actually much more of a major public health problem than childhood
leukaemia is. There is also a suggested way EMFs could affect this condition via
pineal melatonin & serotonin, which we discuss later. In March 1991 at the
'Doll Report' Press Conference, in reply to a question regarding Dr Perry's
work, theNRPB Director, Professor Roger Clarke, replied with: "Depression
and suicide are not in our scheme of things".[26]
Pulsed Radio-frequency and Microwave Studies
Until relatively recently, the general public has not generally been exposed
to significant levels of higher frequency EMFs, unless they live near a major
civilian or military transmitting site.
Research in this area began to emerge in the 1960s, mainly as a result of
Russian work. This led the Russians to develop a standard for public exposure to
microwave and RF EM fields of 10 mW/cm2, which was 1000 times lower
that the limit of 10 mW/cm2 in the West. Current U.K. 'restrictions'
(Investigation Levels) rise from 0.66 mW/cm2 at 12MHz up to still the
10 mW/cm2 level at microwave frequencies [27].
Dr Stanislaw Szmigielski reported [28] on a five year retrospective study of
Polish military personnel exposed to RF and microwave fields at work-day levels
below 200 µW/cm2, the Polish 'safety level'. The highest risk
appeared for malignancies originating from the haemato-lymphatic systems, with a
death rate raised about seven-fold. Other common neoplasms were located in the
alimentary tract and the skin. An ongoing study of the same group showed a
continuing, highly statistically significant, increase in the incidence of all
forms of cancer.
A study of cancer in the Swedish electronics industry also found
significantly elevated incidence of cancers [29]. Sam Milham, in the U.S.A.,
studying a group of amateur radio operators, found a significant excess of
deaths due to acute myeloid leukaemia, multiple myeloma, and non-Hodgkin's
lymphomas [30].
A number of people have found increased eye cataract problems associated with
low levels of RF exposure and with extensive VDU (computer screen) use.
In Britain the Royal Signals Research Establishment, at Malvern, has had a
brain tumour incidence over six times the national average.
In June 1993, in an unprecedented move, a military research laboratory in the
U.S.A. unilaterally declared a 100 µW/cm2 limit for 30 MHz to
100 GHz. Dr Cletus Kanavy wrote [31]:
"The biological effects of microwave radiation on living organisms have been
the subject of extensive research for the past four decades. The most
comprehensive programs were conducted by the Soviet and Eastern Bloc nations.
The U.S. research community was aware of the Soviet findings of deleterious
biological effects at exposures well below the (U.S.) ANSI standards. The Soviet
findings were rejected for various reasons." "The literature published in the
late 1980s is abundant with information on non-thermal effects which are
produced at levels below the ANSI standards." "The principle electromagnetic
biological effects of greatest concern are behavioural aberrations, neural
network perturbations, fetal (embryonic) tissue damage (inducing birth defect),
cataractogenesis, altered blood chemistry, metabolic changes and suppression of
the endocrine and immune systems".
One of the concerning issues is an apparent breakdown of the blood-brain
barrier, allowing blood-borne toxins into the brain.
A large amount of data exists, both experimental animal data and human
clinical evidence, to support the existence of chronic, low-level field
exposure, non-thermal effects at levels below 100 mW/cm2.
The heads of users of cellular telephones will experience levels above this,
as will the bodies of operators of hand held radar speed meters. Cellular
telephone masts are now appearing on and near residential housing in the U.K.
Many schools in the U.S.A are now banning them on their property.
Possible mechanisms
Scientific acceptance of the ELF interaction has been hampered by a lack of a
believable mechanism. The way that the biological and physical sciences are
separately taught has also hindered understanding.
However this, in itself, should not be a barrier to introducing restrictions
to exposure. We still do not know the actual mechanisms by which cigarette
smoking, asbestos fibres or DDT cause cancers, but we have accepted the
epidemiological evidence and have introduced laws to limit or reduce human
exposure. Electric and magnetic ELF fields induce currents in living tissue. The
basis of most interaction models has involved cell membrane field changes which
then affect the cell.
Free-radical interactions have also been implicated, particularly in regard to
the actual initiation of a cancer. It has been repeatedly shown that once a cell
has become deranged then the potential tumour is more likely to develop, and to
develop more quickly, in the presence of low levels of ELF magnetic fields.
Indeed, in the author's view, it is much more likely that low levels of ELF
fields are a hazard because of their effect of reducing the immune system's
competence at dealing with problems, rather than actual direct cell damage.
A number of possible resonance mechanisms have now been proposed to explain
how low levels of low frequency electric and magnetic fields could affect
biological processes. The most promising of these seem to involve interactions
which appear to occur at ion cyclotron resonance frequencies. Complex nuclear
electro-magnetic resonances require a steady background magnetic field combined
with either an oscillating electric field applied at right-angles to the
background field, or an oscillating magnetic field applied parallel to the
background magnetic field. The magnitudes and relative directions of the two
fields are a critical factor in the resonance conditions.
The magnitude of the background 'steady' field sets the resonance frequencies
which need to be applied - the actual strength of the alternating field does not
have a linear relationship with its effect. There is likely to be a threshold
level below which the energy which the alternating field adds to the resonant
particles is inadequate to produce a measured effect. There will then be a band
where the effect will increase, and there will come a point where the
alternating field dominates the particle's environment and the resonance
conditions will then practically cease to be effective.
Just as a radio receiver can be used to detect and decode a specific signal
at an intensity below background noise, there is considerable evidence that
coherent time-varying fields which coincide with natural cellular resonances can
have biological effects at very low levels. Resonances are likely to be
activated at their fundamental and harmonic frequencies.
In 1982 Dr Jafary-Asl, at Salford University, reported that yeast cells
displayed various complex resonances which depended on both the steady
background magnetic field acting together with smaller alternating magnetic (or
electric) fields. The advantage of NMR (nuclear magnetic resonance) or other
complex electromagnetic resonances being the activating cause basis of cellular
interactions is that the energy in the field is concentrated on specific charged
particles or ions and this would give a feasible and scientifically acceptable
mechanism of interaction.
In 1985, both Dr Carl Blackman of the US EPA, and Dr Abe Libhoff, working
independently, integrated Jafary-Asl's ideas with attempts to explain Bawin and
Adey's experiments which showed such cellular responses as calcium ion efflux
when living nerve cells were exposed to ELF fields. When other labs had tried to
replicate the work they found the similar calcium ion efflux but at different
ELF frequencies. Blackman & Libhoff found that they could mathematically
relate the frequency required to cause calcium efflux from cells with the local
geomagnetic field in the laboratory. Dr Libhoff, and others, have shown that
cell mitosis (division) can be speeded up by applying ELF fields, and the
likelihood of genetic errors increased.
One theoretical mechanism, originally described as ion cyclotron resonance,
has gained support [32]. This relates the motion of electrically charged
particles to the magnetic fields surrounding them. A number of the ions in blood
are in the critical mass range for resonance in the Earth's geomagnetic field
and an alternating field between 25 and 500Hz. Power-line fields together with
the Earth's geomagnetic field can provide resonance conditions for Calcium,
Sodium, Lithium, Potassium, hydroxyl and hydronium ions in an aqueous mix [33],
all of which play key roles in living systems [34]. Calcium ions have a powerful
effect on human cell membrane function and affect physiological processes such
as muscle contraction, egg fertilisation and cell division.
Unfortunately the use of the word 'cyclotron' has caused some confusion, as
it is not classical cyclotron resonance. Calculating the likely resonance
frequencies is difficult because ions in an aqueous environment have attached
numbers of water molecules which will reduce the resonant frequencies. A number
of fairly similar models have been proposed, one by Lednev [35], and another by
Drs. Male (Nat.Grid) and Edmonds [36]. Drs Jafary-Asl and Smith of Salford
University have also proposed a relevant quantum magnetic resonance model [37].
Although all these models show how ELF fields could explain some cellular
observations, they do not necessarily mean that these effects will have human
health implications.
Dr John Male (Nat. Grid, ex CEGB) has published a paper describing one of
these complex resonances which he calls 'ion vibrational precession occurring at
the Larmor frequency' which is affected by fields which satisfy the above
'cyclotron' resonance conditions [38]. He points out that although this is a
possible interaction mechanism there is no reason to assume it would produce
adverse health effects.
A clear example of how modern medical physics uses NMR is in the NMI scanners
which can now be found in most major hospitals. Here they apply very high steady
magnetic fields and correspondingly high radio frequencies in order to obtain
the fine detail that they need, but the principle is exactly the same. Hydrogen
nuclei in cancer tissue return a different signal to ones in normal healthy
tissue. This is just the same sort of resonance as is discussed above.
While the effects of these complex resonances at the level of ions and
molecules may be significant, the resulting changes in the structure and
functioning of the cells is likely to be far more important as regards the
possibility of causing adverse health effects.
To our knowledge, only one study has actually looked with some detail at
these issues. This is in a retrospective analysis of a previously published
study carried out in Los Angeles County, U.S.A. The original study [39] was
published in 1991 and had looked at 232 leukaemia cases in children under the
age of 10 between 1980 and 1987, 128 of which had also had their home's static
magnetic field measured although not used in the analysis. As originally
reported the study had found a statistically significant 115% increased risk of
childhood leukaemia associated with proximity to high current cables, but not to
measured magnetic fields.
Dr Bowman, wanting to investigate the resonance theories, calculated that
there would be two resonance bands which fell into the Los Angeles conditions.
Only 46 of the original 128 cases, for which the value of the static magnetic
field was known, satisfied his theoretical resonance conditions. He found that
the data showed an odds ratio (OR) of 2.4 for cases who lived in average fields
from 70 to 140nT, rising to an OR of 6.0 for children exposed to background
ambient fields above 300nT. This compares with the original analysis of the data
which ignored the static field level and did not find a leukaemia/ELF magnetic
field asscociation. His study was limited by many factors, but shows evidence of
the need to include this important extra information in epidemiological studies.
"This is the way to the future", he said.
Since before seeing Dr Bowman's results, the author (Alasdair Philips) has
repeatedly called for the strength and direction of the background static field
to be measured in relation to the power-frequency electric and magnetic field
strengths. It would be normal scientific practice to include the measurement of
all parameters which are implicated in any of the proposed mechanisms of
interaction of the phenomena being studied. It is difficult to understand why
this has not been done in the epidemiological work done to date, nor has it been
included at the time of writing this (February 1994), in the Protocol of the
latest UKCCS childhood cancer study.
Another hypothesis shows how electro-magnetically altered spin states in
haemoglobin molecules can produce a significant net magnetic moment. This would
attract and trap lymphocyte cells, significantly impairing the immune system
response [40].
The Pineal connection
Deep in the centre of our head we have a tiny, pea-sized, pine-cone shaped
pineal gland. Some early philosophers considered it the "seat of the soul".
Until fairly recently the gland was considered a fairly insignificant curiosity.
Indeed, this was just what Sir Richard Doll said about it at the Doll Report
Press Conference. However, in recent years, it has become recognised as a highly
important endocrine organ of the human body.
The Pineal is the remnant of the philosophers' and mystics' "third eye". It
was sensitive to light levels and was located on the top of the head of many
early vertebrates. For most animals, including humans, this gland has moved down
to be in one of the innermost, and protected, areas of the head. It is a very
active organ, having the second highest blood flow after the kidneys, and is equal
in volume to the pituitary. While being right in the centre of the brain, it is
actually outside the blood-brain barrier. This is a membrane which goes right
around the brain and protects it from unwanted chemicals in the blood stream.
During the past fifteen years scientists have discovered just what an
important function this gland seems to play. It produces a number of very active
chemical substances, including important neuro-hormones. Some affect the actions
of most of the other glands in the body, including the pituitary. In 1980 it was
found that EMFs affected the activity of pineal cells, and this was confirmed in
1983 [41].
A main function of the pineal gland is the synthesis of the neurohormone
melatonin from the neurochemical serotonin.
Melatonin plays a major part in controlling human circadian rhythms, its
production peaks at night and is suppressed by bright lights and low level ELF
magnetic fields. Serotonin plays important roles in many bodily processes
including the effectiveness of the immune system. Both of these chemicals are
known to affect mood changes and are linked with depressive illness. An
interesting study of clinically depressed people published in the Lancet in 1987
[42] showed lowered levels of serotonin in every case.
Lowered melatonin has been associated with sleep problems, lethargy, mood
alterations, psychiatric disorders immunodeficiency, and Alzheimer's disease.
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