EMF-Portal | Primary DNA damage in human blood lymphocytes exposed in vitro to 2450 MHz radiofrequency radiation

Primary DNA damage in human blood lymphocytes exposed in vitro to 2450 MHz radiofrequency radiation med./bio.

Aim of study (acc. to editor)

Endpoint

Exposure

2.45 GHz

Exposure	Parameters
Exposure 1: 2.45 GHz Modulation type: pulsed Exposure duration: continuous for 2 h	power: 21 W (net forward power) power density: 5 mW/cm² mean (±7%) SAR: 2.135 W/kg mean (± 0.005 W/kg) SAR: 5.015 W/kg maximum (see add. information)

Exposure 1

Main characteristics

Frequency	2.45 GHz
Type	electromagnetic field
Charakteristic	near field
Exposure duration	continuous for 2 h

Modulation

Modulation type	pulsed
Pulse width	10 µs
Duty cycle	10 %
Repetition frequency	10 kHz

Exposure setup

Exposure source	horn antenna anechoic chamber 35.5 x 25.5 cm, in a vertically downward direction
Distance between exposed object and exposure source	1.75 m
Chamber	The anechoic room of 5.2 x 3.35 x 3.35 m was maintained at 22 ± 1°C. A Plexiglas (0.6-cm thick) box with two compartments and outside dimensions of 24.5 x 21.0 x 3.7 cm was placed in a tightly fitting pressed-foam box of 27 x 22 x 7 cm which was positioned directly under the horn antenna.
Setup	Four T-25 tissue culture flasks were positioned in the open upper compartment of 1.2 cm height, three of them containing 6 ml of whole blood, the fourth one being used for temperature monitoring. The compartment was filled with warm water up to the height of the medium in the flasks. The closed lower compartment was circulated with warm water to maintain the liquid in the flasks at 37°C.
Sham exposure	A sham exposure was conducted.
Additional info	The pressed-foam box for simultaneous sham exposure was placed at the far end of the anechoic room away from the horn. Control samples were incubated for 2 h minus 5 min and in the end exposed to 50 cGy of ionizing radiation from a ¹³⁷Cs γ-ray source at a dose rate of 1.008 cGy/min.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power	21 W	-	-	-	net forward power
power density	5 mW/cm²	mean	measured	-	±7%
SAR	2.135 W/kg	mean	calculated	-	± 0.005 W/kg
SAR	5.015 W/kg	maximum	calculated	-	see add. information

Additional parameter details

The SAR was calculated using FDTD analysis. The values varied from 8.175 x 10^-5 to 5.015 W/kg at different cell positions in the flasks. 90, 75, 50, 25, and 10% of the cells were exposed to SARs greater than 0.950, 1.395, 2.080, 2.730, and 3.520 W/kg, respectively.

Measurement and calculation details

The power density in the center of the field at the location intended for exposure of the cells was measured using a calibrated electromagnetic radiation monitor and probe. The variation at the four flask positions was ±7%.

Reference articles

Vijayalaxmi et al. (1997): Proliferation and cytogenetic studies in human blood lymphocytes exposed in vitro to 2450 MHz radiofrequency radiation

Exposed system:

intact cell/cell culture

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: primary DNA damage (single-strand breaks and alkalilabile lesions; alkaline comet assay (tail length, tail intensity, tail moment (tail length x tail intensity or percent migrated DNA)))

Investigated system:

intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Air Force Office of Scientific Research (AFOSR), USA

Koyama S et al. (2007): Effects of 2.45 GHz electromagnetic fields with a wide range of SARs on bacterial and HPRT gene mutations

Vijayalaxmi (2006): Cytogenetic studies in human blood lymphocytes exposed in vitro to 2.45 GHz or 8.2 GHz radiofrequency radiation