Medical/biological study (experimental study)

Effect of high-density extremely low frequency magnetic field on sister chromatid exchanges in mouse m5S cells med./bio.

By: Yaguchi H, Yoshida M, Ejima Y, Miyakoshi J

Published in: Mutat Res Genet Toxicol Environ Mutagen 1999; 440 (2): 189-194

Aim of study (acc. to author)

To investigate the effects on the DNA and the cell survival of mouse cells exposed to extremely low frequency magnetic field in vitro.

Background/further details

The cells were exposed to extremely low frequency magnetic field alone, treated with mitomycin C (4, 10 and 40 nM) alone or treated with "mitomycin C plus extremely low frequency magnetic field exposure".

Endpoint

genotoxicity/mutation: DNA damage

Exposure

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 42 h	magnetic flux density: 50 mT effective value
Exposure 2: 60 Hz Exposure duration: continuous for 42 h	magnetic flux density: 5 mT effective value
Exposure 3: 60 Hz Exposure duration: continuous for 42 h	magnetic flux density: 400 mT effective value

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 42 h

Exposure setup

Exposure source	Helmholtz coils
Chamber	Acrylic resin CO₂ incubator with an inner space of 300 mm x 45 mm x 400 mm for exposure housing ten 10 cm culture dishes. For control experiments, a conventional incubator in a separate room was used.
Additional info	The whole set-up was shielded by Permalloy C.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	50 mT	effective value	measured	-	-

Measurement and calculation details

The distribution of the magnetic field was measured with a Gauss meter and was almost homogeneous within 3% difference in the exposure space .

Exposure 2

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 42 h

Exposure setup

Exposure source	Helmholtz coils
Chamber	CO₂ incubator with an exposure space of 14 cm height x 20 cm diameter housing sixteen 10 culture dishes.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	5 mT	effective value	measured	-	-

Exposure 3

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 42 h

Exposure setup

Exposure source	coil(s)
Chamber	600 silicon steel strips, each 0.5 mm thick making a core. Two copper coils (10 x 20 mm²) penetrate into the silicon steel core. The incubator (inner space 190 x 220 x 28 mm³) was inserted into the inner space of the core. Magnetic field was homogeneous within 1% difference for the area housing ten culture dishes.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	400 mT	effective value	measured	-	-

Reference articles

Miyakoshi J et al. (1996): Exposure to magnetic field (5 mT at 60 Hz) does not affect cell growth and c-myc gene expression
Miyakoshi J et al. (1994): A newly designed experimental system for exposure of mammalian cells to extremely low frequency magnetic fields

Exposed system:

intact cell/cell culture
mouse m5S cells

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: sister chromatid exchange, number of sister chromatid exchanges/chromosome (fluorescence plus Giemsa staining)
cell viability/cell division/proliferation: cell survival (number of survival colonies), cell cycle progression (proliferation index)

Investigated system:

intact cell/cell culture
chromosomes

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The cells exposed to 400 mT extremely low frequency magnetic field exhibited a significant elevation of the sister chromatid exchange frequencies. No significant difference was observed in cells exposed to 5 and 50 mT extremely low frequency magnetic field.
The exposure to extremely low frequency magnetic field did not influence the proliferation index value.The proliferation index value in mitomycin C treated cells and in "mitomycin C treated cells plus extremely low frequency magnetic field exposure" were significantly lower.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Ministry of Education, Culture, Sports, Science and Technology, Japan

Celikler S et al. (2009): A biomonitoring study of genotoxic risk to workers of transformers and distribution line stations
Koyama S et al. (2008): Extremely low frequency (ELF) magnetic fields enhance chemically induced formation of apurinic/apyrimidinic (AP) sites in A172 cells
Wahab MA et al. (2007): Elevated sister chromatid exchange frequencies in dividing human peripheral blood lymphocytes exposed to 50 Hz magnetic fields
Testa A et al. (2004): Evaluation of genotoxic effect of low level 50 Hz magnetic fields on human blood cells using different cytogenetic assays
Stronati L et al. (2004): Absence of genotoxicity in human blood cells exposed to 50 Hz magnetic fields as assessed by comet assay, chromosome aberration, micronucleus, and sister chromatid exchange analyses
Cho YH et al. (2003): The effect of extremely low frequency electromagnetic fields (ELF-EMF) on the frequency of micronuclei and sister chromatid exchange in human lymphocytes induced by benzo(a)pyrene
Heredia-Rojas JA et al. (2001): Cytological effects of 60 Hz magnetic fields on human lymphocytes in vitro: sister-chromatid exchanges, cell kinetics and mitotic rate
Gamble SC et al. (1999): Syrian hamster dermal cell immortalization is not enhanced by power line frequency electromagnetic field exposure
Antonopoulos A et al. (1995): Cytological effects of 50 Hz electromagnetic fields on human lymphocytes in vitro
Valjus J et al. (1993): Analysis of chromosomal aberrations, sister chromatid exchanges and micronuclei among power linesmen with long-term exposure to 50-Hz electromagnetic fields
Livingston GK et al. (1991): Reproductive integrity of mammalian cells exposed to power frequency electromagnetic fields
Khalil AM et al. (1991): Cytogenetic effects of pulsing electromagnetic field on human lymphocytes in vitro: chromosome aberrations, sister-chromatid exchanges and cell kinetics
Rosenthal M et al. (1989): Effects of 50 Hertz electromagnetic fields on proliferation and on chromosomal alterations in human peripheral lymphocytes untreated or pretreated with chemical mutagens
Nordenson I et al. (1988): Chromosomal effects in lymphocytes of 400 kV-substation workers
Cohen MM et al. (1986): The effect of low-level 60-Hz electromagnetic fields on human lymphoid cells. II. Sister-chromatid exchanges in peripheral lymphocytes and lymphoblastoid cell lines
Bauchinger M et al. (1981): Analysis of structural chromosome changes and SCE after occupational long-term exposure to electric and magnetic fields from 380 kV-systems

Effect of high-density extremely low frequency magnetic field on sister chromatid exchanges in mouse m5S cells med./bio.

Aim of study (acc. to author)

Background/further details

Endpoint

Exposure

Exposure 1

Main characteristics

Exposure setup

Parameters

Measurement and calculation details

Exposure 2

Main characteristics

Exposure setup

Parameters

Exposure 3

Main characteristics

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

Related articles