Intermittent Extremely Low Frequency Electromagnetic Fields
Cause DNA Damage In A Dose-Dependent Way
By Ivancsits S, Diem E, Jahn O, Rudiger HW. Division of Occupational Medicine,
University Hospital/AKH, Waehringer Guertel 18-20, 1090, Vienna, Austria.
OBJECTIVES. Epidemiological studies have reported an association between
exposure to extremely low frequency electromagnetic fields (ELF-EMFs) and
increased risk of cancerous diseases, albeit without dose-effect relationships.
The validity of such findings can be corroborated only by demonstration
of dose-dependent DNA-damaging effects of ELF-EMFs in cells of human origin
in vitro.
METHODS. Cultured human diploid fibroblasts were exposed to intermittent
ELF electromagnetic fields. DNA damage was determined by alkaline and neutral
comet assay.
RESULTS. ELF-EMF exposure (50 Hz, sinusoidal, 1-24 h, 20-1,000 MicroTesla,
5 min on/10 min off) induced dose-dependent and time-dependent DNA single-strand
and double-strand breaks. Effects occurred at a magnetic flux density as
low as 35 MicroTesla being well below proposed International Commission
of Non-Ionising Radiation Protection (ICNIRP) guidelines. After termination
of exposure the induced comet tail factors returned to normal within 9
h.
CONCLUSION. The induced DNA damage is not based on thermal effects and
arouses concern about environmental threshold limit values for ELF exposure.
Int Arch Occup Environ Health. 2003 Jun 12 in print
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&lis
_uids=12802592&dopt=Abstract
and
Evaluation Of Rat Thyroid Gland Morphophysiological Status After Three
Months Exposure To 50 Hz Electromagnetic Field
By Rajkovic V, Matavulj M, Gledic D, Lazetic B.
Department of Histology and Embryology, Institute of Biology, Faculty of
Sciences, University of Novi Sad, Trg Dositeja Obradovica 2, 21000, Novi
Sad, Yugoslavia
Objective of our study was to use morphophysiological criteria in order
to determine the sensitivity of male rat thyroid gland to an extremely
low frequency electromagnetic field (ELF-EMF) influence and the ability
of the gland to repair after period of exposure.
Animals were exposed to 50Hz, 50-500 MicroTesla ELF-EMF for 3 months when
a part of them (group I) were sacrificed, while the rest of animals were
subjected to recovery evaluation of the gland and sacrificed after 1 (group
II), 2 (group III) and 3 (group IV) weeks. Histological and stereological
analyses were performed on paraffin and semifine thyroid gland sections.
Serum T3 and T4 were also determined.
Histological and stereological analyses showed that the volume density
of follicular epithelium and thyroid activation index decreased, while
the volume density of colloid and capillary network increased in group
I, II and III. The values of all these parameters in group IV were similar
to corresponding controls. Serum T3 and T4 concentrations were significantly
lower in all exposed animals, except in group I.
Results of this study demonstrate that after significant morphophysiological
changes caused by ELF-EMF exposure thyroid gland recovered morphologically,
but not physiologically, during the investigated repair period.
Tissue Cell. 2003 Jun;35(3):223-231.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12798131&dopt=Abstract
and
Childhood Leukemia: Electric And Magnetic Fields As Possible Risk Factors
By Brain JD, Kavet R, McCormick DL, Poole C, Silverman LB, Smith TJ, Valberg
PA, Van Etten RA, Weaver JC.
Department of Environmental Health, Harvard School of Public Health, Boston,
Massachusetts, USA.
Numerous epidemiologic studies have reported associations between measures
of power-line electric or magnetic fields (EMFs) and childhood leukemia.
The basis for such associations remains unexplained. In children, acute
lymphoblastic leukemia represents approximately three-quarters of all U.S.
leukemia types.
Some risk factors for childhood leukemia have been established, and others
are suspected. Pathogenesis, as investigated in animal models, is consistent
with the multistep model of acute leukemia development. Studies of carcinogenicity
in animals, however, are overwhelmingly negative and do not support the
hypothesis that EMF exposure is a significant risk factor for hematopoietic
neoplasia.
We may fail to observe effects from EMFs because, from a mechanistic perspective,
the effects of EMFs on biology are very weak. Cells and organs function
despite many sources of chemical "noise" (e.g., stochastic, temperature,
concentration, mechanical, and electrical noise), which exceed the induced
EMF "signal" by a large factor.
However, the inability to detect EMF effects in bioassay systems may be
caused by the choice made for "EMF exposure." "Contact currents"
or "contact voltages" have been proposed as a novel exposure
metric, because their magnitude is related to measured power-line magnetic
fields. A contact current occurs when a person touches two conductive surfaces
at different voltages. Modeled analyses support contact currents as a plausible
metric because of correlations with residential magnetic fields and opportunity
for exposure.
The possible role of contact currents as an explanatory variable in the
reported associations between EMFs and childhood leukemia will need to
be clarified by further measurements, biophysical analyses, bioassay studies,
and epidemiology.
Environ Health Perspect. 2003 Jun;111(7):962-970.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12782499&dopt=Abstract
Informant: Reinhard Rueckemann
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Mechanism
Please look at this text on the mechanisms of the EMF (too many scientists
'officials' say still " there are no explanations "!) http://www.csif-cem.org/hspen.html
Here is the abstract :
EMF and Stress proteins (Hsp) or Heat shock proteins Richard GAUTIER (Dr
en pharmacie), Roger SANTINI (Dr es sciences) http://www.csif-cem.org le
17/06/2003
Abstract: Increase of synthesis of Hsp by the electromagnetic fields (EMF)
generally or by the radio frequencies of the mobile telephony in particular
was widely demonstrated. By studying works relative to the cellular biochemistry
we realizes that these mechanisms are known (activation of the way of the
MAP Kinase and Hsp, deregulation of the protein synthesis, apoptose pathway)
and consequences in sanitary terms established, whether it is in term of
resistance in anti-cancerous treatments, of confusions of the intellectual
activity, infringement of the BHE, the deficit of the immunity, the development
of cancer.
Informant: Dr Richard Gautier |
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