Medical/biological study (experimental study)

Evaluation of the cytogenotoxic damage in immature and mature rats exposed to 900 MHz radiofrequency electromagnetic fields med./bio.

By: Atli Sekeroglu Z, Akar A, Sekeroglu V

Published in: Int J Radiat Biol 2013; 89 (11): 985-992

Aim of study (acc. to author)

To examine whether exposure to electromagnetic fields has a genotoxic and cytotoxic effect on bone marrow cells in immature (2 weeks old) and mature (10 weeks old) rats.

Background/further details

The following groups of rats were examined (n=8 per group): 1.) immature rats, killed directly after sham exposure period, 2.) immature rats, killed directly after exposure period, 3.) immature rats, killed 15 days after exposure period, 4.) mature rats, killed directly after sham exposure period, 5.) mature rats, killed directly after exposure period and 6.) mature rats, killed 15 days after exposure period.
Four rats were used for the micronucleus test and four rats for the chromosomal analysis and mitotic index.

Endpoint

genotoxicity/mutation: DNA damage
cell viability/cell division/proliferation: cytotoxicity

Exposure

- RF field
- CW continuous wave
- mobile communications
- mobile phone
- GSM

Exposure	Parameters
Exposure 1: 900 MHz Modulation type: CW Exposure duration: continuous for 2 h/day for 45 days	power: 2 W (applied output power) SAR: 0.76 W/kg mean (whole body) (0.38-0.78 W/kg (for immature rats)) SAR: 0.37 W/kg mean (whole body) (0.31-0.52 W/kg (for mature rats)) electric field strength: 28.1 V/m mean (± 4.8 V/m (for immature rats)) electric field strength: 20 V/m mean (± 3.2 V/m (for mature rats))

General information

Rats were divided into six groups with eight animals each: i) immature control group ii) immature rats exposed to EMF iii) immature rats granted a recovery period of 15 days after exposure termination iv) mature control group v) mature rats exposed to EMF vi) mature rats granted a recovery period of 15 days after exposure termination

Exposure 1

Main characteristics

Frequency	900 MHz
Type	electromagnetic field
Exposure duration	continuous for 2 h/day for 45 days

Modulation

Modulation type	CW

Exposure setup

Exposure source	GSM simulator
Chamber	rats were exposed in a pie cage restrainer for 12 rats made of plexiglas with several air holes; galvanized plate (1mm thick) was placed at the bottom for grounding of the static field
Setup	antenna heights were approximately 15 cm; antenna was located in the middle of the pie cage restrainer and fixed as closely as possible to the whole body of the rat (about 6 cm from the head)
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power	2 W	-	-	-	applied output power
SAR	0.76 W/kg	mean	calculated	whole body	0.38-0.78 W/kg (for immature rats)
SAR	0.37 W/kg	mean	calculated	whole body	0.31-0.52 W/kg (for mature rats)
electric field strength	28.1 V/m	mean	measured	-	± 4.8 V/m (for immature rats)
electric field strength	20 V/m	mean	measured	-	± 3.2 V/m (for mature rats)

Measurement and calculation details

background levels of other RF sources in the laboratory were measured with a spectrum analyzer/satellite receiver and an electrical field meter, stability of the frequency system was checked every week by using a spectrum analyzer

Reference articles

Dasdag S et al. (2009): Effect of mobile phone exposure on apoptotic glial cells and status of oxidative stress in rat brain
Koyu A et al. (2005): Effects of 900MHz electromagnetic field on TSH and thyroid hormones in rats

Exposed system:

animal
rat/Wistar albino
whole body

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: DNA damage (chromosome aberration (Giemsa staining) and micronucleus test (May-Grünwald-Giemsa staining); light microscopy)
cell viability/cell division/proliferation: cytotoxicity: mitotic index (Giemsa staining; light microscopy); ratio of polychromatic erythrocytes to normochromatic erythrocytes

Investigated system:

intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The data showed significant increases in chromosome aberrations and micronucleus frequency, while the mitotic index and the ratio of polychromatic erythrocytes was significantly decreased in bone marrow cells of all exposure groups compared with the control group. Additionally, the cytotoxic and genotoxic damage was more remarkable in immature rats than in mature rats. The 15 days of recovery period was insufficient to compensate the genotoxic damage in immature rats after exposure.

Study character:

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

Study funded by

not stated/no funding

Sekeroglu V et al. (2012): Cytotoxic and genotoxic effects of high-frequency electromagnetic fields (GSM 1800MHz) on immature and mature rats
Trosic I et al. (2011): Effect of electromagnetic radiofrequency radiation on the rats' brain, liver and kidney cells measured by comet assay
Gurbuz N et al. (2010): Is There Any Possible Genotoxic Effect in Exfoliated Bladder Cells of Rat Under the Exposure of 1800 MHz GSM-Like Modulated Radio Frequency Radiation (RFR)?
Ziemann C et al. (2009): Absence of genotoxic potential of 902 MHz (GSM) and 1747 MHz (DCS) wireless communication signals: In vivo two-year bioassay in B6C3F1 mice
Juutilainen J et al. (2007): Micronucleus frequency in erythrocytes of mice after long-term exposure to radiofrequency radiation
Belyaev IY et al. (2006): Exposure of rat brain to 915 MHz GSM microwaves induces changes in gene expression but not double stranded DNA breaks or effects on chromatin conformation
Verschaeve L et al. (2006): Investigation of co-genotoxic effects of radiofrequency electromagnetic fields in vivo
Ferreira AR et al. (2006): Ultra high frequency-electromagnetic field irradiation during pregnancy leads to an increase in erythrocytes micronuclei incidence in rat offspring
Gorlitz BD et al. (2005): Effects of 1-week and 6-week exposure to GSM/DCS radiofrequency radiation on micronucleus formation in B6C3F1 mice
Vijayalaxmi et al. (2004): Micronuclei in peripheral blood and bone marrow cells of mice exposed to 42 GHz electromagnetic millimeter waves
Vijayalaxmi et al. (2003): Genotoxic potential of 1.6 GHz wireless communication signal: in vivo two-year bioassay
Vijayalaxmi et al. (2001): Micronuclei in the peripheral blood and bone marrow cells of rats exposed to 2450 MHz radiofrequency radiation
Vijayalaxmi et al. (1997): Frequency of micronuclei in the peripheral blood and bone marrow of cancer-prone mice chronically exposed to 2450 MHz radiofrequency radiation
McRee DI et al. (1981): Incidence of sister chromatid exchange in bone marrow cells of the mouse following microwave exposure