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Expert' exchange of letters over the safety of mobile phone masts

 


On 7th October 2009 the Kerryman newspaper published a letter by Dr. Keith Nolan of the Centre for Telecommunications Value-Chain Research in Dublin suggesting that the dangers of mobile phone masts were being exaggerated as they only emit weak non-ionising radiation which causes little, if any damage, to health.

On 14th October Dr Andrew Goldsworthy responded maintaining that, amongst other effects, weak non-ionising radiation has been known for the last 30 years to disrupt cell membranes, especially those of lysosomes, 'structures in living cells that contain digestive enzymes and are normally used to digest waste for recycling. When these leak, they can release their enzymes and do serious damage to the rest of the cell, including to its DNA...'

Other experts in the field have added their comments to those of Dr Goldsworthy.

Professor Denis Henshaw of the HH Wills Physics Laboratory at the University of Bristol:

There is another irony in what Dr Nolan failed to understand and what Dr Goldsworthy has said.
For something like 50 years it was axiomatic that DNA strand breaks and cancer induced by ionising radiation was (and only could be) a result of the ionising particle (alpha, beta or gamma ray) actually cutting the DNA at the point the break is seen.
Then suddenly these assumptions ended in tears with the discovery of The Bystander Effect in which cells that had never been hit by ionising radiation, but were in the vicinity of those that were, or were cultured in culture medium which had previously had cells in them that were irradiated, had DNA strand breaks induced in them. This occurs by a cell signaling effect from hit cells. In fact, we now know that the link between radon exposure in the home and lung cancer is NOT primarily an effect of DIRECT alpha-particle hits to cells, rather is an effect in ‘Bystander cells’ – on those not hit !.

The problem is that the term ‘strand break’ is itself misleading. Here is an extract from some of my notes on this:
Magnetic Fields and DNA strand breaks

Historically, it was argued that unlike ionizing radiation, the low quantum energy of MFs was insufficient to cause DNA strand breaks and therefore could not cause cancer.
The term ‘strand break’ is potentially misleading to the general reader. Lea (1946) used the term structural change to describe breakages in chromosomes, which appeared to be caused by an ionising particle passing through or in the immediate vicinity of the chromosome at the point where the breakage occurred. Lea acknowledged that such changes were actually due to radiation given to the cell at a stage prior to metaphase. However, adoption of the term breakage implied that the DNA had been broken, chopped or cut by the passage of radiation at that specific location on the chromosome.
Almost 50 years later Nagaswa & Little (1992) demonstrated that genetic chromosomal damage may be induced by low doses of a-radiation in cell nuclei not actually traversed by an a-particle. The phenomenon was termed the bystander effect. It has since been demonstrated for high and low-LET radiation, certain chemicals and heavy metals (Little 2006, Xiao et al. 2004) and forms a central concept in modern radiobiology.
The important conceptual conclusion is that chromosomal aberrations reflecting DNA strand breaks represent replication failures in the DNA template. Such failures are associated with coding information and not necessarily quantum energy at the level associated with ionising radiation. The myriad of responses involving genetic damage seen following exposures to MFs are consistent with such loss of coding information.

Lea DE. 1946. Actions of radiations on living cells. Cambridge University Press.
Nagasawa H and Little JB, 1992. Induction of sister chromatid exchanges by extremely low doses of a-particles. Cancer Research, 52, 6394-6396
Xiao Y, de Feyter E, van Outen CH, Stap J, Hoebe R, Havenith S, van Noorden CJF, Aten JA. 2004. Induction and detection of bystander effects after combined treatment of cells with 5-bromo-2’-deoxyurine, Hoechst 33 258 and ultraviolet A light. International Journal of Radiation Biology 80:105-114.
Little JB. 2006. Cellular radiation effects and the bystander response. Mutation Research 597:113-118.



Dr George Carlo of the Science and Public Policy Institute in Washington DC:

This is an important discussion. There is no doubt that the 'bystander effect' and other indirect effects have significant intercellular/inter-organelle communication disruption and interference in the etiologic chain. Membrane integrity issues such as leakage are certainly integrally involved in pathology and induction of symptoms as well. As we have become empowered with new knowledge and advances based on the synthesis of old knowledge with new, there has emerged a focus on these indirect effects (e.g. biologically and biochemically mediated) as the primary non-thermal mechanisms.
However, I believe we need to be careful not to oversimplify the complexity of the EMR effect to our detriment. The science shows that 'thermal' impacts are likely a continuum based on molecular spins etc. and not a purely threshold phenomenon (e.g. above a certain intensity level there is heat and below it there is no heat). Thus, 'thermal' and 'non-thermal' are qualitative measures, not quantitative (irrespective of the global over-fascination with SAR as a quantitative measure). The science also shows that even with low intensity EMR insults that can qualitatively be defined as 'non-thermal' there are direct effects on cellular physiology, DNA repair, protein synthesis, mRNA/DNA transcription etc. These effects appear to be energetically mediated -- with molecular spin components no doubt -- influencing strand folding and even genetic up and down regulation.
Low intensity EMR classified as 'non-thermal' indeed exerts both direct and indirect effects that can be adverse. As such, the distinction between 'thermal' and 'non-thermal' is itself an oversimplification that in many ways plays into the hands of industry naysayers.
My suggestion is that we would be well served to add another vocabulary dimension to categorization of EMR effects along the lines of 'direct and indirect' as opposed to only 'thermal' and 'non-thermal'.....

 

Professor Denis Henshaw of the HH Wills Physics Laboratory at the University of Bristol:

Yes, yes, yes and your bottom line (literally in your [Dr Carlo's] e-mail above) is quite right.

You and Dr Goldsworthy are (of course) both talking about spin chemistry and about the whole concept of 'temperature'. Chyptochomes operate by the 'Radical Pair Mechanism' in which low intensity MFs change
the spin states of pairs of free radical in a manner that makes them more likely to be avialable (to have time) to do biological damage (singlet totriplet conversion). This is quite divorced from the classic temperature/energy, indeed it is around 100,000 times lower in energy. But 'spin' can and does control chemical reactions, i.e. nothing to do with classical energy, rather it's quantum spin energy. Yes, there's a lot in this and it's all well established.

 

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First Published in October 2009

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