Medical/biological study (experimental study)

Non-thermal DNA breakage by mobile-phone radiation (1800 MHz) in human fibroblasts and in transformed GFSH-R17 rat granulosa cells in vitro med./bio.

By: Diem E, Schwarz C, Adlkofer F, Jahn O, Rüdiger H

Published in: Mutat Res Genet Toxicol Environ Mutagen 2005; 583 (2): 178-183

Aim of study (acc. to author)

To confirm or disprove the genotoxic potential of radiofrequency electromagnetic field by investigating possible DNA-damaging effects in different cell types by using a newly developed sophisticated exposure system (publication 7926).

Background/further details

The work is part of the REFLEX project (Risk Evaluation of Potential Environmental Hazards From Low Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods), funded by the European Union.

Endpoint

genotoxicity/mutation: DNA single-strand breaks and double-strand breaks

Exposure

- mobile communications
- GSM

Exposure	Parameters
Exposure 1: 1,800 MHz Modulation type: CW Exposure duration: continuous for 4, 16 and 24 h	SAR: 2 W/kg mean
Exposure 2: 1,800 MHz Modulation type: CW Exposure duration: intermittent, 5 min on/10 min off, for 4, 16 and 24 h	SAR: 2 W/kg mean
Exposure 3: 1,800 MHz Modulation type: pulsed Exposure duration: intermittent, 5 min on/10 min off, for 4, 16 and 24 h	SAR: 2 W/kg mean
Exposure 4: 1,800 MHz Modulation type: pulsed Exposure duration: continuous for 4, 16 and 24 h	SAR: 1.2 W/kg mean

Exposure 1

Main characteristics

Frequency	1,800 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	continuous for 4, 16 and 24 h

Modulation

Modulation type	CW

Exposure setup

Exposure source	R18 hollow rectangular waveguides
Chamber	Two waveguides were placed inside a commercial incubator at 37°C, 5% CO₂, and 95% humidity. A computer randomly determined which of the two waveguides was used for exposure (blind design).
Setup	Six Petri dishes were exposed simultaneously in the waveguide and placed in the H-field maxima.
Additional info	Each exposure level was tested in duplicate.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	2 W/kg	mean	measured and calculated	-	-

Measurement and calculation details

Temperature and fields (SAR) were continuously monitored at the location of the dishes (see reference articles). Measurements of the exposure system by the provider showed a non-uniformity of SAR for monolayer cell cultures of less than 30% and a temperature load of less than 0.03 °C per W/kg of SAR.

Exposure 2

Main characteristics

Frequency	1,800 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	intermittent, 5 min on/10 min off, for 4, 16 and 24 h

Modulation

Modulation type	CW

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	2 W/kg	mean	measured and calculated	-	-

Exposure 3

Main characteristics

Frequency	1,800 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	intermittent, 5 min on/10 min off, for 4, 16 and 24 h

Modulation

Modulation type	pulsed
Pulse width	576 µs
Duty cycle	12.5 %
Repetition frequency	217 Hz
Pulse type	rectangular
Additional info	GSM basic signal having a frame length of 4.61 ms. Since every 26th frame was idle, an 8 Hz modulation component was integrated into the signal.

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	2 W/kg	mean	measured and calculated	-	-

Exposure 4

Main characteristics

Frequency	1,800 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	continuous for 4, 16 and 24 h

Modulation

Modulation type	pulsed
Pulse width	576 µs
Duty cycle	12.5 %
Repetition frequency	217 Hz
Pulse type	rectangular
Additional info	GSM talk signal alternating between GSM basic (97 s) and DTX mode (50 s) simulating a conversation.

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	1.2 W/kg	mean	measured and calculated	-	-

Reference articles

Schuderer J et al. (2003): Effect of the meniscus at the solid/liquid interface on the SAR distribution in Petri dishes and flasks
Schönborn F et al. (2001): Basis for optimization of in vitro exposure apparatus for health hazard evaluations of mobile communications

Exposed system:

intact cell/cell culture
GFSH-R17 (transformed rat granulosa cells) and human diploid fibroblasts

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: DNA single-strand breaks and double-strand breaks (alkaline and neutral comet assay)

Investigated system:

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Electromagnetic field exposure (SAR 1.2 or 2 W/kg; different modulations; during 4, 16 and 24 h; intermittent or continuous wave) induced DNA single-strand breaks and double-strand breaks. The evaluation became significant after 16 h of exposure. Effects occurred (after 16 h irradiation) in both cell types and after different modulations. The intermittent exposure showed a stronger effect than continuous exposure.
The authors conclude that the induced DNA damage cannot be based on thermal effects.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

European Union (EU)/European Commission
VERUM Foundation (Stiftung für Verhalten und Umwelt), Germany

Replication studies

Speit G et al. (2007): Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in cultured mammalian cells are not independently reproducible

Comments on this article

Adlkofer F (2014): Whether or not the genotoxic effects of exposure to continuous wave (CW) radio frequency electromagnetic fields (RF-EMF) in HL-60 cells are reproducible, is still an open question
Speit G (2014): Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) reported by the REFLEX project are not reproducible
Adlkofer F et al. (2011): [About the dealing with scientific results in mobile communications research at the Medical University of Vienna]
Lerchl A et al. (2010): Critical comments on DNA breakage by mobile-phone electromagnetic fields [Diem et al., Mutat. Res. 583 (2005) 178-183]
Baan RA (2010): Letter of concern
Rudiger HW (2009): Letter to the editor: doubts raised about the blinding process do not apply to the Diem et al. paper
Baan RA (2009): Editorial: controversy related to two published papers
Tuffs A (2008): University calls for mobile phone research to be withdrawn after technician admits faking data
Vogel G (2008): Scientific misconduct. Fraud charges cast doubt on claims of DNA damage from cell phone fields
Vijayalaxmi et al. (2006): Comments on: "DNA strand breaks" by Diem et al. [Mutat. Res. 583 (2005) 178-183] and Ivancsits et al. [Mutat. Res. 583 (2005) 184-188]

Hou Q et al. (2015): Oxidative changes and apoptosis induced by 1800-MHz electromagnetic radiation in NIH/3T3 cells
Moraitis N et al. (2015): In-vitro assessment of Jurkat T-cells response to 1966 MHz electromagnetic fields in a GTEM cell
Speit G et al. (2013): Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in HL-60 cells are not reproducible
Franzellitti S et al. (2010): Transient DNA damage induced by high-frequency electromagnetic fields (GSM 1.8GHz) in the human trophoblast HTR-8/SVneo cell line evaluated with the alkaline comet assay
Valbonesi P et al. (2008): Evaluation of HSP70 expression and DNA damage in cells of a human trophoblast cell line exposed to 1.8 GHz amplitude-modulated radiofrequency fields
Schwarz C et al. (2008): Radiofrequency electromagnetic fields (UMTS, 1,950 MHz) induce genotoxic effects in vitro in human fibroblasts but not in lymphocytes
Speit G et al. (2007): Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in cultured mammalian cells are not independently reproducible
Baohong W et al. (2007): Evaluating the combinative effects on human lymphocyte DNA damage induced by ultraviolet ray C plus 1.8 GHz microwaves using comet assay in vitro
Juutilainen J et al. (2007): Micronucleus frequency in erythrocytes of mice after long-term exposure to radiofrequency radiation
Maes A et al. (2006): Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation
Scarfi MR et al. (2006): Exposure to radiofrequency radiation (900 MHz, GSM signal) does not affect micronucleus frequency and cell proliferation in human peripheral blood lymphocytes: an interlaboratory study
Stronati L et al. (2006): 935 MHz cellular phone radiation. An in vitro study of genotoxicity in human lymphocytes
Lixia S et al. (2006): Effects of 1.8 GHz radiofrequency field on DNA damage and expression of heat shock protein 70 in human lens epithelial cells
Federal Office for Radiation Protection (BfS) (2006): [Statement on the final report of the REFLEX research association (5th EU Framework Program)]

Non-thermal DNA breakage by mobile-phone radiation (1800 MHz) in human fibroblasts and in transformed GFSH-R17 rat granulosa cells in vitro med./bio.

Aim of study (acc. to author)

Background/further details

Endpoint

Exposure

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

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

Replication studies

Comments on this article

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