Medical/biological study (experimental study, review/survey)

Cellular effects of electromagnetic fields med./bio.

By: Naarala J, Höytö A, Markkanen A

Published in: Altern Lab Anim 2004; 32 (4): 355-360

Aim of study (acc. to author)

To study the effects of 50 Hz extremely low frequency magnetic fields (caused by power lines and electric devices) and 872 MHz or 900 MHz radiofrequency fields (emitted by mobile phones and their base stations) on cellular ornithine decarboxylase activity, cell cycle kinetics, cell proliferation, and necrotic or apoptotic cell death.

Background/further details

UV radiation, serum deprivation, or fresh medium addition were used as co-exposures.
The study summarizes previous published (see publication 10487 and publication 6742) and unpublished data of the authors work on different cell culture systems and compares the results to those of similar other studies.

Endpoint

cell function: ornithine decarboxylase activity
cell viability/cell division/proliferation: cell cycle kinetics, cell proliferation, apoptosis

Exposure

- 50/60 Hz
- power transmission line
- mobile communications
- GSM

Exposure	Parameters
Exposure 1: 900 MHz Modulation type: pulsed Exposure duration: continuous for 1 to 24 h	SAR: 6 W/kg maximum (0.2-6 W/kg)
Exposure 2: 900 MHz Modulation type: CW Exposure duration: continuous for 1 to 24 h	SAR: 6 W/kg maximum (0.2-6 W/kg)
Exposure 3: 872 MHz Modulation type: pulsed Exposure duration: continuous for 1 to 24 h	SAR: 6 W/kg maximum (0.2-6 W/kg)
Exposure 4: 872 MHz Modulation type: CW Exposure duration: continuous for 1 to 24 h	SAR: 6 W/kg maximum (0.2-6 W/kg)
Exposure 5: 50 Hz Exposure duration: continuous for 7 h	magnetic flux density: 120 µT (± 5 µT)

General information

UV radiation, serum deprivation, or fresh medium addition were used as co-exposures.

Exposure 1

Main characteristics

Frequency	900 MHz
Type	electromagnetic field
Charakteristic	guided field
Polarization	unspecified
Exposure duration	continuous for 1 to 24 h

Modulation

Modulation type	pulsed
Repetition frequency	217 Hz
Additional info	GSM modulator

Exposure setup

Exposure source	monopole cavity resonator RF generator
Chamber	The exposure chamber was an aluminium RF resonator with a plastic culture chamber and a water circulation heat exchanger positioned under a glass surface on which the cell culture dishes were placed. RF power was fed into the exposure chamber with a monopole post. Two identical chambers were used, one for EMF and one for sham exposure. Warm air (37°C) and CO₂ (5%) were fed into the chambers from an incubator.
Setup	Glass instead of plastic Petri dishes were used for better thermal contact.
Sham exposure	A sham exposure was conducted.
Additional info	A temperature adjustment curve was used to keep the measured temperature of the cell culture medium constant (± 0.3°C) at SAR values up to 6 W/kg.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	6 W/kg	maximum	measured and calculated	-	0.2-6 W/kg

Measurement and calculation details

The EF inside the chamber, below the heat exchanger, was monitored from another monopole post with an RF power meter. SAR estimation based on FDTD calculations was compared with the measured EF profile. The agreement between the field values was excellent (better than 5%). The calculated SAR within a Petri dish was 2.5 W/kg ± 30% for 1 W of dissipated power.

Exposure 2

Main characteristics

Frequency	900 MHz
Type	electromagnetic field
Charakteristic	guided field
Polarization	unspecified
Exposure duration	continuous for 1 to 24 h

Modulation

Modulation type	CW

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	6 W/kg	maximum	measured and calculated	-	0.2-6 W/kg

Exposure 3

Main characteristics

Frequency	872 MHz
Type	electromagnetic field
Charakteristic	guided field
Polarization	unspecified
Exposure duration	continuous for 1 to 24 h

Modulation

Modulation type	pulsed
Repetition frequency	217 Hz
Additional info	GSM modulator

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	6 W/kg	maximum	measured and calculated	-	0.2-6 W/kg

Exposure 4

Main characteristics

Frequency	872 MHz
Type	electromagnetic field
Charakteristic	guided field
Polarization	unspecified
Exposure duration	continuous for 1 to 24 h

Modulation

Modulation type	CW

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	6 W/kg	maximum	measured and calculated	-	0.2-6 W/kg

Exposure 5

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 7 h

Exposure setup

Exposure source	not specified
Chamber	wooden exposure system [Markkanen et al., 2001]
Additional info	Cells were irradiated by UVB for 10 min at a dose of 175 J/m² and a dose rate of 0.292 J/m² per second during the MF exposure which continued to the end of the experiment. This exposure setup was also used to expose cells to UV radiation in UV + RF experiments.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	120 µT	-	-	-	± 5 µT

Reference articles

Markkanen A et al. (2001): Effects of 50 Hz magnetic field on cell cycle kinetics and the colony forming ability of budding yeast exposed to ultraviolet radiation

Exposed system:

intact cell/cell culture
yeast cell strains (Saccharomyces cerevisiae)
mammalian cell lines (L929, SH-SY5Y, C6, primary rat astrocytes)

Methods Endpoint/measurement parameters/methodology

cell function: ornithine decarboxylase activity (release of ¹⁴C-labelled CO₂ from ¹⁴C-labelled L-ornithine)
cell viability/cell division/proliferation: cell cycle kinetics (propidium iodide stain); cell proliferation (Almar Blue assay (for mammalian cells and CFU (for yeast)); necrotic or apoptotic cell death (caspase-3 acitivity & annexin/propidium iodide stain; flow cytometry)

Investigated system:

isolated bio./chem. substance
intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The data on cell cycle kinetics suggest different delay times in "UV + magnetic field"-exposed yeast cells compared with UV-only exposed yeast cells. Magnetic field exposure may slow down the recovery of yeast cells from growth delay caused by UV damage.
There were no clear effects of radiofrequency exposure alone on ornithine decarboxylase activities, although there seemed to be cell type specificity.
Cell proliferation induced by medium change was slightly increased by radiofrequency irradiation. Additionally, a GSM-modulated radiofrequency increased UV-induced apoptosis in yeast cells (this effect seemed to be modulation specific).
In conclusion, magnetic fields and radiofrequency fields seem to have some effects on cellular growth and cell death mechanisms. These effects are clearly revealed only when cells are co-exposed with a known damaging agent.

Study character:

medical/biological study
experimental study
review/survey
full/main study

Study funded by

Finnish Graduate School of Environmental Health (SYTYKE)
Finnish mobile phone manufacturers and operators
GSM Association, UK/Ireland
Imatran Voima Foundation, Finland
Ministry of Agriculture and Forestry, Finland
Mobile Manufacturers Forum (MMF), Belgium
Tekes (National Technology Agency), Finland

Comments on this article

Janssens JP (2005): Mobile phones and cancer?

Campisi A et al. (2010): Reactive oxygen species levels and DNA fragmentation on astrocytes in primary culture after acute exposure to low intensity microwave electromagnetic field
Billaudel B et al. (2009): Effects of exposure to DAMPS and GSM signals on ornithine decarboxylase (ODC) activity: II. SH-SY5Y human neuroblastoma cells
Billaudel B et al. (2009): Effects of exposure to DAMPS and GSM signals on ornithine decarboxylase (ODC) activity: I. L-929 mouse fibroblasts
Pavicic I et al. (2008): In vitro testing of cellular response to ultra high frequency electromagnetic field radiation
Lee JJ et al. (2008): Acute radio frequency irradiation does not affect cell cycle, cellular migration, and invasion
Joubert V et al. (2008): Apoptosis is Induced by Radiofrequency Fields through the Caspase-Independent Mitochondrial Pathway in Cortical Neurons
Joubert V et al. (2007): No apoptosis is induced in rat cortical neurons exposed to GSM phone fields
Höytö A et al. (2007): Ornithine decarboxylase activity is affected in primary astrocytes but not in secondary cell lines exposed to 872 MHz RF radiation
Novak J et al. (2007): Effects of low-frequency magnetic fields on the viability of yeast Saccharomyces cerevisiae
Panagopoulos DJ et al. (2007): Cell death induced by GSM 900-MHz and DCS 1800-MHz mobile telephony radiation
Vanderwaal RP et al. (2006): HSP27 phosphorylation increases after 45°C or 41°C heat shocks but not after non-thermal TDMA or GSM exposures
Lantow M et al. (2006): Comparative study of cell cycle kinetics and induction of apoptosis or necrosis after exposure of human mono mac 6 cells to radiofrequency radiation
Gurisik E et al. (2006): An in vitro study of the effects of exposure to a GSM signal in two human cell lines: monocytic U937 and neuroblastoma SK-N-SH
Pavicic I et al. (2006): Comparison of 864 MHz and 935 MHz microwave radiation effects on cell culture
Takashima Y et al. (2006): Effects of continuous and intermittent exposure to RF fields with a wide range of SARs on cell growth, survival, and cell cycle distribution
Markkanen A et al. (2004): Apoptosis induced by ultraviolet radiation is enhanced by amplitude modulated radiofrequency radiation in mutant yeast cells
Tokalov SV et al. (2003): The heat shock-induced cell cycle arrest is attenuated by weak electromagnetic fields
Yoshizawa H et al. (2002): No effect of extremely low-frequency magnetic field observed on cell growth or initial response of cell proliferation in human cancer cell lines
Tian F et al. (2002): Exposure to Power Frequency Magnetic Fields Suppresses X-Ray-Induced Apoptosis Transiently in Ku80-Deficient xrs5 Cells
Markkanen A et al. (2001): Effects of 50 Hz magnetic field on cell cycle kinetics and the colony forming ability of budding yeast exposed to ultraviolet radiation
Wei M et al. (2000): Exposure to 60 Hz magnetic fields and proliferation of human astrocytoma cells in vitro

Cellular effects of electromagnetic fields med./bio.

Aim of study (acc. to author)

Background/further details

Endpoint

Exposure

General information

Exposure 1

Main characteristics

Modulation

Exposure setup

Parameters

Measurement and calculation details

Exposure 2

Main characteristics

Modulation

Exposure setup

Parameters

Exposure 3

Main characteristics

Modulation

Exposure setup

Parameters

Exposure 4

Main characteristics

Modulation

Exposure setup

Parameters

Exposure 5

Main characteristics

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

Comments on this article

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