Medical/biological study (experimental study)

GSM and DCS Wireless Communication Signals: Combined Chronic Toxicity/Carcinogenicity Study in the Wistar Rat med./bio.

By: Smith P, Kuster N, Ebert S, Chevalier HJ

Published in: Radiat Res 2007; 168 (4): 480-492

Aim of study (acc. to editor)

To study the effects of GSM and DCS wireless communication signals on carcinogenicity in rats.

Background/further details

A total of 1200 rats were used. Groups of 65 male and 65 female rats were exposed to GSM and DCS signals at three different SAR values (4 W/kg, 1.33 W/kg, 0.44 W/kg). In addition, there was a sham exposed group for each signal type. An additional group of 65 males and 65 females was kept unexposed and unrestrained and served as the cage control.

Endpoint

cancer: carcinogenicity

Exposure

- mobile communications
- digital mobile phone
- GSM

Exposure	Parameters
Exposure 1: 902 MHz Modulation type: pulsed Exposure duration: repeated daily exposure, 2 h/day, 5 days/week, for 52 or 104 weeks	SAR: 3.7 W/kg average over time (whole body) SAR: 1.23 W/kg average over time (whole body) SAR: 0.41 W/kg average over time (whole body)
Exposure 2: 1,747 MHz Modulation type: pulsed Exposure duration: repeated daily exposure, 2 h/day, 5 days/week, for 52 or 104 weeks	SAR: 4 W/kg average over time (whole body) SAR: 1.33 W/kg average over time (whole body) SAR: 0.44 W/kg average over time (whole body)

General information

The GSM and DCS experiments were conducted in adjacent rooms, each having 16 exposure units installed. A placement rotation scheme was applied to all rats in order to minimize dose differences due to signal differences within and between exposure units.

Exposure 1

Main characteristics

Frequency	902 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	repeated daily exposure, 2 h/day, 5 days/week, for 52 or 104 weeks

Modulation

Modulation type	pulsed
Additional info	GSM signal

Exposure setup

Exposure source	cavity resonator waveguide
Chamber	The exposure unit for up to 17 animals consisted of a circular cascade of 17 electromagnetically isolated and resonant waveguides (terminated by stainless steel wires), all excited by one quarter-loop antenna placed in the center and providing uniform circular excitation (maximum deviation of isotropy of ±0.2 dB).
Setup	Rats were individually restrained in horizontal position in metal-free polycarbonate tubes and were positioned in optimal H-polarization with their centers of mass at 150 ± 2 mm from the shortcut thus providing a reasonably homogeneous exposure for varying sizes. Missing animals were replaced with a dummy (container simulating the absorption characteristics) to minimise imbalances of the excitations.
Sham exposure	A sham exposure was conducted.
Additional info	The RF signals were generated by a digital GSM/DCS signal generator combined with a frame generator and control unit [Kainz et al., 2006]. Each slot was modulated with a random code.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	3.7 W/kg	average over time	measured and calculated	whole body	-
SAR	1.23 W/kg	average over time	measured and calculated	whole body	-
SAR	0.41 W/kg	average over time	measured and calculated	whole body	-

Additional parameter details

Each exposure session was divided into three phases of 40 min: (1) GSM Basic (non-DTX) mode with one slot active per basic frame and each 26th basic frame idle. (2) GSM Talk mode consisting of temporal changes between the non-DTX (average 10.8 s) and DTX (average 5.6 s) modes. (3) GSM Environment mode consisting of a GSM Talk signal further amplitude-modulated by a power control function statistically based on measurements performed by France Telecom [Wiart et al., 2000]. The peak (slot-averaged) SAR level for all three phases was the same, however, the resulting average SARs varied: 100% (GSM Basic), 70% (GSM Talk), and 26% (GSM Environment). The SAR values indicated above are those for GSM Basic. The SAR levels in the GSM study had to be decreased in three steps over time since the body weight increase of the rats was greater than predicted and the available power was insufficient to maintain 4 W/kg. So, the SAR (GSM Basic) averaged over the entire exposure period was only 3.7 W/kg for the high-dose group. The SAR values for the medium- and low-dose groups were also adjusted accordingly to keep the target ratio of three between the dose groups.

Measurement and calculation details

During exposure, the electric field strength inside the waveguide cavity was monitored and controlled almost continuously at two different places. A new methodology was used to obtain comprehensive dosimetric information for whole-body and peak spatial SAR as well as the averaged values for the most important organs including the uncertainty as well as the instant and life-long variations [Kuster et al., 2006].

Exposure 2

Main characteristics

Frequency	1,747 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	repeated daily exposure, 2 h/day, 5 days/week, for 52 or 104 weeks

Modulation

Modulation type	pulsed
Additional info	DCS signal

Exposure setup

Exposure source	same setup as exposure 1
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	4 W/kg	average over time	measured and calculated	whole body	-
SAR	1.33 W/kg	average over time	measured and calculated	whole body	-
SAR	0.44 W/kg	average over time	measured and calculated	whole body	-

Additional parameter details

The peak (slot-averaged) SAR level for all three phases was the same (33.2 W/kg for the high-dose group), however, the resulting average SARs varied: 100% (GSM Basic), 70% (GSM Talk), and 26% (GSM Environment). The SAR values indicated above are those for GSM Basic.

Reference articles

Kainz W et al. (2006): Development of novel whole-body exposure setups for rats providing high efficiency, National Toxicology Program (NTP) compatibility and well-characterized exposure
Kuster N et al. (2006): Methodology of detailed dosimetry and treatment of uncertainty and variations for in vivo studies
Wiart J et al. (2000): Analysis of the influence of the power control and discontinuous transmission on RF exposure with GSM mobile phones

Exposed system:

animal
rat/Han Wistar (HanBrl:WIST)
whole body

Methods Endpoint/measurement parameters/methodology

cancer: primary/benign/malignant neoplasms (incidence, latency, multiplicity); palpable masses; number of rats with metastases
morphol./histopathol. changes: histopathological examination (hematoxylin-eosin stain; light microscopy)
mortality rate; clinical signs (e.g. behaviour; respiratory, circulatory, CNS effects), clinical pathological investigation (hematology, clinical biochemistry); body and organ weight; food consumption; opthalmoscopic examination

Investigated system:

tissue slices
isolated organ
blood samples
investigation on living organism

Investigated organ system:

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

The study produced no evidence that radiofrequency electromagnetic field exposure under these conditions had any effect on the incidence or severity of any non-neoplastic condition or the type, incidence, multiplicity and latency of any neoplastic lesion.

Study character:

medical/biological study
experimental study
full/main study
double-blind study

Study funded by

European Project PERFORM-A
European Union (EU)/European Commission
GSM Association, UK/Ireland
Mobile Manufacturers Forum (MMF), Belgium
State Secretariat for Education and Research (SER; Staatssekretariat für Bildung und Forschung), Switzerland

Falcioni L et al. (2018): Report of final results regarding brain and heart tumors in Sprague-Dawley rats exposed from prenatal life until natural death to mobile phone radiofrequency field representative of a 1.8 GHz GSM base station environmental emission
Lee HJ et al. (2011): Lymphoma development of simultaneously combined exposure to two radiofrequency signals in AKR/J mice
Bartsch H et al. (2010): Effect of chronic exposure to a GSM-like signal (mobile phone) on survival of female Sprague-Dawley rats: Modulatory effects by month of birth and possibly stage of the solar cycle
Saran A et al. (2007): Effects of exposure of newborn patched1 heterozygous mice to GSM, 900 MHz
Oberto G et al. (2007): Carcinogenicity Study of 217 Hz Pulsed 900 MHz Electromagnetic Fields in Pim1 Transgenic Mice
Sommer AM et al. (2007): Lymphoma Development in Mice Chronically Exposed to UMTS-Modulated Radiofrequency Electromagnetic Fields
Shirai T et al. (2007): Lack of promoting effects of chronic exposure to 1.95-GHz W-CDMA signals for IMT-2000 cellular system on development of N-ethylnitrosourea-induced central nervous system tumors in F344 rats
Tillmann T et al. (2007): Carcinogenicity study of GSM and DCS wireless communication signals in B6C3F1 mice
Sommer AM et al. (2006): 50 Hz magnetic fields of 1 mT do not promote lymphoma development in AKR/J mice
Huang TQ et al. (2005): Effect of radiofrequency radiation exposure on mouse skin tumorigenesis initiated by 7,12-dimethybenz[alpha]anthracene
Shirai T et al. (2005): Chronic exposure to a 1.439 GHz electromagnetic field used for cellular phones does not promote N-ethylnitrosourea induced central nervous system tumors in F344 rats
Sommer AM et al. (2004): The risk of lymphoma in AKR/J mice does not rise with chronic exposure to 50 Hz magnetic fields (1 microT and 100 microT)
Sommer AM et al. (2004): No effects of GSM-modulated 900 MHz electromagnetic fields on survival rate and spontaneous development of lymphoma in female AKR/J mice
LaRegina MC et al. (2003): The Effect of Chronic Exposure to 835.62 MHz FDMA or 847.74 MHz CDMA Radiofrequency Radiation on the Incidence of Spontaneous Tumors in Rats
Heikkinen P et al. (2003): Effects of mobile phone radiation on UV-induced skin tumourigenesis in ornithine decarboxylase transgenic and non-transgenic mice
Bartsch H et al. (2002): Chronic exposure to a GSM-like signal (mobile phone) does not stimulate the development of DMBA-induced mammary tumors in rats: results of three consecutive studies
Heikkinen P et al. (2001): Effects of mobile phone radiation on X-ray-induced tumorigenesis in mice
Imaida K et al. (2001): Lack of promotion of 7,12-dimethylbenz[a]anthracene-initiated mouse skin carcinogenesis by 1.5 GHz electromagnetic near fields
Zook BC et al. (2001): The effects of 860 MHz radiofrequency radiation on the induction or promotion of brain tumors and other neoplasms in rats
Adey WR et al. (2000): Spontaneous and nitrosourea-induced primary tumors of the central nervous system in Fischer 344 rats exposed to frequency-modulated microwave fields
Adey WR et al. (1999): Spontaneous and nitrosourea-induced primary tumors of the central nervous system in Fischer 344 rats chronically exposed to 836 MHz modulated microwaves
Higashikubo R et al. (1999): Radiofrequency electromagnetic fields have no effect on the in vivo proliferation of the 9L brain tumor
Imaida K et al. (1998): The 1.5 GHz electromagnetic near-field used for cellular phones does not promote rat liver carcinogenesis in a medium-term liver bioassay
Repacholi MH et al. (1997): Lymphomas in Eµ-Pim1 transgenic mice exposed to pulsed 900 MHz electromagnetic fields
Salford L et al. (1997): Brain tumour development in rats exposed to electromagnetic fields used in wireless cellular communication
Toler JC et al. (1997): Long-term, low-level exposure of mice prone to mammary tumors to 435 MHz radiofrequency radiation
Wu RY et al. (1994): Effects of 2.45-GHz microwave radiation and phorbol ester 12-O-tetradecanoylphorbol-13-acetate on dimethylhydrazine-induced colon cancer in mice

GSM and DCS Wireless Communication Signals: Combined Chronic Toxicity/Carcinogenicity Study in the Wistar Rat med./bio.

Aim of study (acc. to editor)

Background/further details

Endpoint

Exposure

General information

Exposure 1

Main characteristics

Modulation

Exposure setup

Parameters

Additional parameter details

Measurement and calculation details

Exposure 2

Main characteristics

Modulation

Exposure setup

Parameters

Additional parameter details

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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