Em Fields On Brain Tumor Incidence - Chemicals And Cell Phones

March 24, 2008

_http://www.newmediaexplorer.org/chris/2004/10/20/em_fields_on_brain_tumor_inc

idence_chemicals_and_cell_phones.htm_

(http://www.newmediaexplorer.org/chris/2004/10/20/em_fields_on_brain_tumor_incid\

ence_chemicals_and_cell_phones.htm)

.... " In a series of studies, Hardell and colleagues have examined the

relationship between the side of the head habitually used in operation of

cellular

and cordless phones and a possible relationship to the site of brain tumors

([Hardell et al., 2003]). The risk for _ipsilateral _

(http://dictionary.reference.com/search?q=ipsilateral%20) (same side) use

significantly increased the

risk for _astrocytoma _

(http://dictionary.reference.com/search?q=astrocytomas%20)

_http://dictionary.reference.com/search?q=astrocytomas%20_

(http://dictionary.reference.com/search?q=astrocytomas%20) for all types of

phones, but

use of the phone on the opposite side of the head was not associated with

significantly increased risk. Overall, use of FM (analog) phones gave an

increased

risk, whereas digital and cordless phones did not increase risks

significantly. " ...

This excellent piece of work by _Dr Adey (so typical of this towering figure

in EM and Cell research)_ (http://www.raven1.net/adeycv.htm)

_http://www.raven1.net/adeycv.htm_ (http://www.raven1.net/adeycv.htm) should

put to rest

the debate on the dangers of Cell phones (obviously this applies to all the

wireless stuff that is so much the rage these days as well) . While the

danger cannot be avoided at least it can be minimized, to some extent, as per

above. Those who insist on using them can further reduce their exposure by

shortening transmissions (cutting out the 'gift of the gab') and listening more

(pun intended)...which besides lessening the exposure should improve their

listen skills (a much maligned attribute of our modern society)..

This paper is a must read for those interested in non thermal effects EMF

(Electromagnetic Fields) particularly the collective cell/neuron

response/behavior/properties to stimuli. It is an eye opener and very useful

when dealing

with vested interests who continually ignore non thermal effects to promote

their wares with self serving rhetoric.

Chris Gupta

5. Influence of EM fields on brain tumor incidence in man and in animal

models (10)

5.1. Epidemiological studies

Environmental EM fields may act jointly with exposure to environmental

chemicals with known cancer-promoting actions in enhancing occupational brain

tumor risks. Experimental evidence supports cell membranes as a site for joint

actions of many chemical cancer promoters with EM fields ([Adey, 1992b]). The

latter include pesticides, weedicides and electrical solvents. A case control

study by the U.S. National Cancer Institute of brain tumor incidence in

RF/microwave occupational exposures ([Thomas et al., 1987]) in the states of

New

Jersey, Pennsylvania and Louisiana concluded that all excess risk for primary

brain tumors in white males aged over 30 years derived from jobs involving

design, manufacture, installation and repair of electronic equipment (Risk

Ratio=2.3, 95% CI=1.3,4.2). Cases were divided into cohorts with 5, 10, 15 and

20+ years of exposure. Risks of astrocytomas increased to ten-fold for those

employed 20 years or more, when concurrent exposure to electrical and

electronic solvents was involved. RRs were not increased in men exposed to

RF/microwave fields, but who never worked in electrical or electronics jobs;

leading the

authors to emphasize concurrent exposures to soldering fumes, solvents and a

variety of chemicals as possible co-factors with RF/microwave fields in

tumor promotion.

In a case-control study of risk factors for gliomas and meningiomas in males

in Los Angeles County, involving 272 men aged 25–69 with primary brain

tumors and 272 matched neighbor controls ([Preston-Martin et al., 1989]),

glioma

(but not meningioma) risk related to prior employment in jobs likely to

involve high exposure to electric and magnetic fields (P<0.05). The risk was

greatest for astrocytoma (OR for employment in such jobs for >5 years=4.3;

CI=1.2–15.6). As in the study of microwave workers cited above, there was

evidence of

concurrent action of chemical factors. More glioma cases had worked in the

rubber industry (discordant pairs 6/1), and more worked in hot processes using

plastics (9/1).

[savitz and Loomis (1995)] have linked work site magnetic field measurements

to individual work histories in a cohort mortality study (138,905 men) at 5

large American electric power companies over a period of 36 years. Brain

cancer risk increased by a factor of 1.94 per microtesla-year of magnetic field

exposure in the previous 2–10 years, with a mortality rate ratio of 2.6 in the

highest exposure category.

In a series of studies, Hardell and colleagues have examined the

relationship between the side of the head habitually used in operation of

cellular and

cordless phones and a possible relationship to the site of brain tumors

([Hardell et al., 2003]). The risk for ipsilateral use significantly increased

the

risk for astrocytoma for all types of phones, but use of the phone on the

opposite side of the head was not associated with significantly increased risk.

Overall, use of FM (analog) phones gave an increased risk, whereas digital

and cordless phones did not increase risks significantly.

5.2. Animal models of brain tumor promotion

There are few accepted animal models of spontaneous malignant central

nervous system (CNS) tumors, although there has been increasing use of the

Fischer

344 rat, with a reported incidence of spontaneous malignant tumors as high as

11%. Two life term studies using this rat model have compared exposures to

the North American Digital Standard (NADC) digital phone field using 11

Time Division Multiple Access (TDMA) modulation pulsed at 50 packets”/sec,

with comparable exposures to the older type of FM (analog) phone fields ([Adey

et al., 1999]; [Adey et al., 2000]). Rats were exposed in utero to a single

dose of the short-lived neurocarcinogen ethylnitrosourea (ENU), and

thereafter, exposed intermittently to either TDMA or FM fields for 23 months.

In the TDMA study, when compared with rats receiving ENU but unexposed, rats

that died from a primary CNS tumor before termination of the study showed a

significant reduction in tumor incidence (P<0.015). A similar but

non-significant reduction in spontaneous tumor incidence occurred in rats

field-exposed

but not receiving ENU (P<0.08). In the balanced design of this experiment,

consistent non-significant differences in survival rates were noted between the

four rat groups, with higher death rates in a progression:

sham/field:sham/sham:ENU/field:ENU/sham. By contrast in the FM study, no

field-related effects

were observed in number, incidence or types of either spontaneous or

ENU-induced CNS tumors.

These observations of an apparent protective effect against ENU-induced and

spontaneous CNS tumors are not isolated. Low dosage of X-rays in fetal rats

at the time of ENU dosage sharply reduce subsequent incidence of induced

tumors ([Warkany et al., 1976]), through activation of AT

(alkylguanine-DNA-alkyltransferase) enzymes that participate in DNA repair

([stammberger et al.,

1990]). Other studies with nonionizing (microwave) fields also suggest their

actions in mechanisms of DNA repair. Modulation of levels of single-strand

breaks

in brain cell DNA has been reported following low-level, long-term microwave

exposure in mice ([sarkar et al., 1994]) and in acute experiments in rats

([Lai and Singh, 1995]).

6. Summary: intrinsic and induced electric fields as threshold determinants

in central nervous tissue; the potential role of cell ensembles

The intact nervous system might be expected to be more sensitive to induced

electric fields and currents than in vitro preparations, due to a higher

level of spontaneous activity and a greater number of interacting neurons.

However, these fields induced in the body are almost always much lower than

those

capable of stimulating peripheral nerve tissue ([saunders and Jefferys,

2002]). Weak electric field effects, below action potential thresholds, have

been

demonstrated in in vitro brain slice preparations ([Faber and Korn; 1989];

[Jefferys, 1995]}.Behavioral sensitivities in sharks and rays may be as low as

0.5 nV/mm for tissue components of electrical fields in the surrounding ocean

([Kalmijn, 1971]), or 100 times below measurable thresholds of individual

electroreceptor organs ([Valberg et al., 1997]).

Research in sensory physiology supports the concept that some threshold

properties in excitable tissues may reside in highly cooperative properties of

a

population elements, rather than in a single detector ([Adey,1998, 2003a, 20

03b]). Seminal observations in the human auditory system point to a receptor

vibrational displacement of 10-11m, or approximately the diameter of a single

hydrogen atom ([bialek, 1983]; [bialek and Wit, 1984]). It is notable that

suppression of intrinsic thermal noise allows the ear to function as though

close to 0 degree K, suggesting system properties inherent in the detection

sequence. Human olfactory thresholds for musk occur at 10-11 M, with odorant

molecules distributed over 240 mm2 ([Adey, 1959]). Human detection of single

photons of bluegreen light occurs at energies of 2.5 eV ([Hagins, 1979]). In

another context, pathogenic bacteria, long thought to function independently,

exhibit ensemble properties by a system recognizing (12) colony numbers as an

essential step preceding release of toxins. These quorum sensing systems may

control expression of virulence factors in the lungs of patients with cystic

fibrosis ([Erickson et al., 2002]).

Although far from a consensus on mechanisms mediating these low-level EMF

sensitivities, appropriate models are based in nonequilibrium thermodynamics,

with nonlinear electrodynamics as an integral feature. Heating models, based

in equilibrium thermodynamics, fail to explain a wide spectrum of observed

nonthermal EMF bioeffects in central nervous tissue. The findings suggest a

biological organization based in physical processes at the atomic level, beyond

the realm of chemical reactions between biomolecules. Much of this signaling

within and between cells may be mediated by free radicals of the oxygen and

nitrogen species. Emergent concepts of tissue thresholds to EMF sensitivities

address ensemble or domain functions of populations of cells, cooperatively

“whispering together “ in intercellular communication, and organized

hierarchically at atomic and molecular levels.

7. See Also Search Neuroscion Bibliographic References

Extracted from:

_Electromagnetic fields, the modulation of brain tissue functions

— A possible paradigm shift in biology

W. Ross Adey_ (http://www.newmediaexplorer.org/chris/adey_encneuro_emfs.pdf)

__

posted by Chris Gupta on Wednesday October 20 2004

updated on Saturday September 24 2005

URL of this article:

_http://www.newmediaexplorer.org/chris/2004/10/20/em_fields_on_brain_tumor_inc

idence_chemicals_and_cell_phones.htm_

(http://www.newmediaexplorer.org/chris/2004/10/20/em_fields_on_brain_tumor_incid\

ence_chemicals_and_cell_phones.htm)

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