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Re:EMF and DNA double-strand breaks



> According to a recent Swedish magazine article based on an interview 
> with two scientists ("ERA" 9/98:43-44), "EMF" can cause DNA 
> double-strand breaks in animal experiments, DSBs (no ref. is given).

Lai and Singh [A,B] reported that exposure of rats to 60-Hz fields at 100, 250 
and 500 microT caused excess DNA strand breaks in brain cells.

This report has not been independently replicated or confirmed; but a similar 
study in which Lai and Singh [C,D] reported excess DNA strand breaks in rat 
brain cells after low-intensity in vivo RF irradiation has failed an attempt 
at confirmation.[E,F]  The attempts to replicate the RF studies have shown 
that the method used by Lai & Singh to kill the animals and isolate the brain 
cells is itself a potent produced of DNA strand breaks.

All other attempts to cause DNA strand breaks by exposure of cultured cells to 
power-frequency fields have failed to find any effects.[G-L]

> The article begins with the "possibility" that "EMF" is a carcinogen.

That is probably reference to a recent US "working group" that classified 
power-frequency fields in IARC Class 2B ("possible human carcinogen") by a 
split vote, but unanimously rejected a classification as IARC 2A ("probable 
human carcinogen")

> On the first 15 lines, it is stated that magnetic fields can be 
> compared to ("equal category" word is used) substances such as 
> chloroform, DDT, lead, saccharin, and most dyes/paints.

chloroform, DDT, lead and saccharin are other agents classified by IARC as 
Class 2B (along with coffee and car exhaust).


---refs----

A)  Lai, H, and Singh, NP: Melatonin and N-tert-butyl-a-phenylnitrone block 
60-Hz magnetic field induced DNA strand breaks in rat brain cells, J. Pineal 
Res., 1997; 22:152-162.

B)  Lai, H, and Singh, NP: Acute exposure to a 60 Hz magnetic field increases 
DNA strand breaks in rat brain cells, Bioelectromag., 1997; 18:156-165.

C)  Lai, H. and Singh, NP: Acute low-intensity microwave exposure increases 
DNA single-strand breaks in rat brain cells, Bioelectromag., 1995; 16:207-210.

D)  Lai, H, and Singh, NP: Single- and double-strand DNA breaks in rat brain 
cells after acute exposure to radiofrequency electromagnetic radiation, Int. 
J. Radiat. Biol., 1996; 69:513-521.

E)  Malyapa, RS, Ahern, EW et al: Measurement of DNA damage following exposure 
to electromagnetic radiation in the cellular communications frequency band 
(835.62 and 847.74 MHz), Radiat. Res., 1997; 148:608-617.

E2) Malyapa, RS, Ahern, EW et al: Measurement of DNA damage following exposure 
to 2450 MHz electromagnetic radiation, Radiat. Res., 1997; 148:618-627.

F)  Malyapa, RS, Ahern, EW et al: DNA damage in rat brain cells after in vivo 
exposure to 2450 MHz electromagnetic radiation and various methods of 
euthanasia, Radiat.Res., 1998; 149:637-645.

G)  Fairbairn, DW, and O'Neill, KL: The effect of electromagnetic field 
exposure on the formation of DNA single strand breaks in human cells, Cell. 
Molec. Biol., 1994; 4:561-567.

H)  Fiorani, M, Cantoni et al: Electric and/or magnetic field effects on DNA 
structure and function in cultured human cells, Mutat. Res., 1992; 282:25-29.

J)  Reese, JA, Jostes, RF, and Frazier, ME: Exposure of mammalian cells to 60-
Hz magnetic or electric fields:  Analysis for DNA single-strand breaks, 
Bioelectromag., 1988; 9:237-247.

K)  Novelli, G., Gennarelli, M., Potenza, L., Angeloni, P., and Dallapiccola, 
B., Study of the effects on DNA of electromagnetic fields using clamped 
homogeneous electric field gel electrophoresis, Biomed. Pharmacother., 1991; 
45:451-454.

L)  D'Agruma, L., Colosimo, A., Angeloni, U., Novelli, G., and Dallapiccola, 
B., Plasmid DNA and low-frequency electromagnetic fields, Biomed. 
Pharmacother., 1993; 47:101-105.


John Moulder (jmoulder@its.mcw.edu)

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