|Betreff: Electromagnetic Fields, Leukaemia and DNA Damage|
|Datum: 29 Sep 2004 15:22:35 -0000|
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Fields of Influence 2
Also see our previous fields of influence series
Debate over the health impacts of weak electromagnetic fields continues unabated as more and more biological effects are documented. This mini-series began in Science in Society 17, where we described how a new physics of the organism that can account for those effects has been systematically ignored and excluded from mainstream discourse. The situation has hardly changed since and requires radical steps to be taken in scientific research funding and in science education.
ISIS Press Release 29/09/04
Electromagnetic Fields, Leukaemia and DNA Damage
Leukaemia, DNA damage in brain cells and other electromagnetic field effects cannot be explained unless scientists communicate and collaborate across the disciplines. Dr. Mae- Wan Ho reports
EMF cancer links
People nowadays are constantly exposed to low-intensity electromagnetic fields (EMFs) at the extremely low frequencies of 50 or 60 Hz whenever they use electricity. Debate over the safety of electromagnetic fields began in the 1950s in the former Soviet Union and in the 1970s in the United States over the construction of high-tension power lines (see "Non-thermal effects", SiS 17).
In March 2002, a study commissioned by the National Radiation Protection Board (NRPB) in the United Kingdom found that exposure to EMFs of 0.4 mTesla (4 mG) or greater doubles the risk of childhood leukaemia (see "Electromagnetic fields double leukaemia risks", SiS 17). But the study failed to draw any firm conclusions because of the absence of any proven biological mechanisms by which such low levels of non-ionising electromagnetic radiation can trigger cancer. The results were downplayed on grounds that very few children would live in homes with EMFs in excess of 0.4mT, though this is debatable (see later).
EMF and childhood leukaemia more strongly linked than appears
But the link between childhood leukaemia and EMF may be far stronger than appears from the epidemiological studies.
Court Brown and Richard Doll first noted in a paper published in 1961  that a new agent causing leukaemia had been introduced first into Britain about 1920 and later into the United States and other countries. A new peak in childhood leukaemia deaths between the ages two and four had emerged in the UK in the 1920s, and in the 50 years starting in 1911, leukaemia mortality at ages under 10 had increased an average of 4.5% per year.
At a conference organised by the charity Children with Leukemia in London, UK, in September 2004, an entire day was devoted to the evidence that EMF is linked to childhood leukaemia. Among the speakers was Dr. Sam Millham of Washington State Department of Health in the United States, who described the remarkable correlation between the emergence of childhood leukaemia and the electrification of homes, which began in the 1920s in the UK and slightly later in the US. In the US, electrification of farms and rural areas lagged behind urban areas until 1958, so there was plenty of opportunity to compare mortality rates due to childhood leukaemia in the death registers .
In the period 1920 to 1960, death from childhood leukaemia between 2-4 years rose from a base line of less than 2 per 100 000 to about 8 per 100 000 among white children only. No such peak is evident for black children in the same period, or for Japanese children as reported in other studies. During 1928-1932, in states with over 75% of homes electrified, leukaemia mortality increased with age for single years for the ages 0 to 4 years, while states with electrification of residences below 75% showed a decreasing trend.
During 1949-1951, all states showed a peak in leukaemia mortality at ages 2-4. At age 0-1, leukaemia mortality was not related to electrification levels. But at ages 2-4, there was a 24% increase in leukaemia mortality for each 10% increase in homes electrified. The peak of leukaemia at ages 2-4 is made up of a single leukaemia subtype, common acute lymphoblastic leukaemia. By this time, the same peak of childhood leukaemia deaths had emerged in black and Japanese children.
Millham and Osslander commented that worldwide, the emergence of this peak tracked electrification. So, even today, places without electricity do not show this peak. They criticised the EMF/cancer epidemiologic studies done long after electrification, which shows a deceptively low (2 to 3 fold) risk with increased exposure to EMFs, simply because there are no truly unexposed control groups on which to make the comparison. Consequently, they estimate that for childhood leukemias between ages 2 to 4, about 75% could be linked to EMF exposure possibly in the mother's womb.
DNA damage in brain cells blocked by anti-oxidants
But other biological effects have emerged. In January 2004, Henry Lai and Narendra Singh of the Bioelectromagnetics Research Laboratory in the University of Washington in Seattle, USA, reported that exposing rats to weak 60 Hz magnetic fields caused DNA breaks in their brain cells and brain-cell death , and furthermore, the DNA damage can be blocked by antioxidants. This suggests that magnetic fields somehow caused the accumulation of oxidative free radicals, which damaged the DNA, leading to cell death.
Lai and Singh had earlier found that rats exposed to a 60 Hz sinusoidal magnetic field for 2 hours at flux density of 0.1 mT (1G) showed an increase in DNA single-strand breaks in their brain cells, whereas an increase in double-strand breaks was found at 0.25mT or greater. Several subsequent investigations have confirmed DNA breakages in a number of different cell lines as the result of exposure to 50 or 60Hz magnetic fields, although other studies failed to confirm the findings.
In one study, an increase in DNA double-strand breaks were found in the brain cells of mice exposed to 7.5mT magnetic fields for 32 days , and after 14 days at 0.5mT . Thus, the effects appear to be cumulative. In human fibroblasts, continuous exposure at 1 mT produced no significant effect, while intermittent exposure (5 min on and 10 min off) produced an increase in DNA single- and double-strand breaks .
Lai and Singh had found in their 1997 study that if they gave the rats melatonin and a 'spin-trap' compound (N-tert-butyl-a-phenylnitrone), both of which scavenge oxidative free radicals, these appear to protect their brain cells against the DNA damage caused by the magnetic fields.
In the new series of experiments, they included a lower field exposure of 0.01m T (0.1G) for 24h or 48h. Increases in single and double strand breaks were already observed at 24h, with larger increases at 48h, again indicating the cumulative nature of the effects.
In brains of rats exposed to magnetic field at 0.5mT for 2 h, significant increases were found, by about 2-fold in both apoptosis ('programmed' cell death initiated by the cell itself) and necrosis (cells killed otherwise).
The antioxidant Trolox (vitamin E analogue) and 7-nitroindazole (an inhibitor of the enzyme that makes nitric oxide, another free radical) and the iron chelator, deferiprone, all blocked the effects of the magnetic field on DNA breaks.
Mechanism emerging for EMF effects?
Lai and Singh proposed that the magnetic field initiates an iron-mediated process that increases free radical formation in the brain cells, leading to DNA damage and cell death. In addition to DNA damage, free radicals can cause damage to other biological molecules such as lipids and proteins and other cell functions.
How does iron get involved? It is involved in the 'Fenton' reaction, which converts hydrogen peroxide to the more potent and toxic hydroxy radical, and iron-induced oxidant formation is known to cause DNA strand breaks, DNA- protein cross-links and many other effects. They suggest that cells with high rates of iron intake such as proliferating cells, cells infected by viruses, and cells with high metabolic rates such as brain cells, would be more susceptible to the effects of magnetic fields on DNA.
The human brain contains relatively high amounts of non- heme iron, probably required in the production and maintenance of myelin, and increased risk of neurodegenerative diseases due to magnetic field exposure could be a result of the death of neurons and glial cells or demyelination. Lai and Singh further pointed out that occupational exposure to extremely low-frequency electromagnetic fields have been associated with increased risks of neurodegenerative diseases including amyotropic lateral sclerosis, Alzheimer's disease and Parkinson's disease.
Recommended exposure limits inadequate
But how relevant are the results to real life? Household and office levels of extremely low-frequency magnetic fields vary between 0.01 to 1 mT, with intermittent levels of more than 10 mT. Levels near a power transmission line are between 10-30mT, where as it could vary between 0.1 to 1mT near some electrical appliances such as electric blankets and hair dryers. Much higher levels are expected in occupational exposures.
The UK NRPB  has lowered its previous recommended exposure limits to those of the ICNIRP (International Commission on Non-Ionizing Radation Protection, an organization of 15 000 scientists from 40 nations). These limits vary with frequency, from 0.04T at up to 1Hz to 0.2 mT or 10W/m2 at 300GHz for the general public, while the occupational limits are respectively 0.2T and 0.45 microT or 50W/m2. For 60Hz EMF, the limit is 0.833G for the general public and 4.2G occupational. As can be seen, these limits are inadequate to prevent DNA damage in brain cells and other associated effects. They are aimed at preventing 'thermal effects' of body tissues over-heating, and not on non-thermal effects. One major (mistaken) argument against weak fields having any effects at all is that they are energetically below the level of random thermal motions [8, 9], which applies strictly to dead tissues or otherwise lifeless systems.
In his talk given to the Children with Leukemia conference, Lai  presented findings showing that cancer cells may be even more susceptible to the EMFs than normal cells, thus offering the prospect that EMFs may be used for cancer therapy, if only one knew how to prevent 'collateral' damage to non-cancer cells.
Non-thermal biological effects no longer in doubt but still in need of explanation
There is little doubt that EMFs over a whole range of frequencies can have biological effects (see also "Mobile phones & brain damage", this series). But the precise mechanism remains elusive. Geneticists latch onto 'susceptibility' genes, biochemists to specific ions, such as iron or calcium, or molecules such as free radicals or heat shock proteins .
Molecular changes associated with exposure to EMFs tell us little about the basic physics of how EMFs can bring about such changes, however. And so the effects of EMFs remain within the realm of phenomenology with contradictory findings, like the related efficacy of homeopathy and other 'subtle' energy medicine.
Lack of cross-disciplinary discourse, research and education
A major difficulty is the lack of truly cross- disciplinary discourse, let alone research aimed at understanding living organisms and cells. I spent nearly 25 years in the biology department of a university struggling to get even a smattering of thermodynamics and other physics and chemistry into the biochemistry course profile; and almost none of my colleagues in the department understood or cared what our research was about.
In my talk to the Children with Leukemia conference, I suggested that EMF sensitivity (non-thermal effects) was due, in the first instance, to the quantum coherence of the organism and its liquid crystalline matrix - consisting of globally oriented macromolecular dipoles and biological water - that provides rapid electrodynamic intercommunications throughout the body [12, 13].
I also showed how that is consistent with the thesis of Gilbert Ling  - the result of 50 years of brilliant research almost totally ignored by the scientific establishment - that the cell is an exquisite "electronic machine" interconnected by long-range induction of electron density changes that affect the state of the cell through the extended protein matrix with its polarised layers of ordered cell water (see "Strong medicine for cell biology", to appear).
Existing physical methods can be used to detect phase changes in biological/cell water, which may in turn enable us to understand the plethora of molecular changes occurring downstream of EMF exposure.
To get at the explanation of EMF effects, we need scientists to talk to each other and collaborate across the disciplines. For that, we need a public funding structure that encourages novel interdisciplinary research instead of reinforcing existing unproductive programmes that discriminate against 'maverick' researchers.
At the moment, research grants and graduate students tend, more and more, to be exclusively awarded to big groups in prestigious universities, which overwhelmingly engage in big, safe projects that have no incentive to be innovative, and indeed, positively discriminate against 'dissenters' and 'mavericks'.
Radical changes are needed in the education of our scientists. Few biologists understand the physical sciences and mathematics well enough to appreciate the contribution they can make to the life sciences; few physical scientists know enough biology to apply their expertise effectively to it. Not enough progress is being made in areas that lie between the traditional disciplines, and even when it is, the results are too often ignored because too many scientists can't understand what their colleagues are talking about.
This article can be found on the I-SIS website at http://www.i- sis.org.uk/ELADD.php
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