Study type: Medical/biological study (experimental study)

Microwaves and cellular immunity. I. Effect of whole body microwave irradiation on tumor necrosis factor production in mouse cells med./bio.

By: Fesenko EE, Makar VR, Novoselova EG, Sadovnikov VB
Published in: Bioelectrochem Bioenerg 1999; 49 (1): 29-35
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Aim of study (acc. to author)

To study the effect of weak 8.15-18 GHz microwaves on the tumor necrosis factor secretion and the T lymphocytes proliferative response.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 10 GHz
Modulation type: CW
Exposure duration: continuous for 0.5 h to 7 days
  • power density: 1 µW/cm² spatial average (0.2-1.6 µW/cm²)
  • SAR: 5 mW/kg (2-5 mW/kg)
Exposure 2: 8.15–18 GHz
Exposure duration: continuous for 0.5 h to 7 days
  • power density: 1 µW/cm² spatial average (0.2-1.6 µW/cm²)
  • SAR: 5 mW/kg (2-5 mW/kg)

General information

A total of 45 and 60 animals were exposed in E1 and E2, respectively. The same numbers of animals were used for cage control. In both experiments, 10 animals were sham irradiated and 10 were untreated. The procedure was double blind.

Exposure 1

Main characteristics
Frequency 10 GHz
Type
Waveform
Exposure duration continuous for 0.5 h to 7 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 80 cm
Setup Groups of five unrestrained mice were exposed in plastic cages (25 cm x 25 cm x 45 cm) without roof. There was no reflecting material on the floor beneath the animals.
Sham exposure A sham exposure was conducted.
Additional info Unexposed cage control animals were housed in a separate room under the same conditions.
Parameters
Measurand Value Type Method Mass Remarks
power density 1 µW/cm² spatial average measured - 0.2-1.6 µW/cm²
SAR 5 mW/kg - estimated - 2-5 mW/kg
Measurement and calculation details

The bell-shaped field distribution in the animal location was mapped using an incident power density meter and a thermistor type probe of 15 cm diameter. Since it was very difficult to perform experimental measurements of real SAR [Khizhnyak et al., 1994], the range was estimated assuming a penetration depth of 2-5 mm [Furia et al., 1986].

Exposure 2

Main characteristics
Frequency 8.15–18 GHz
Type
Waveform
Exposure duration continuous for 0.5 h to 7 days
Modulation
Modulation type cf. additional info
Additional info

swept frequency from 8.15 GHz to 18 GHz with 1 s direct and 16 ms reversed time (output stability better than 12 dB)
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 1 µW/cm² spatial average measured - 0.2-1.6 µW/cm²
SAR 5 mW/kg - estimated - 2-5 mW/kg

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Whole body microwave irradiation caused a significant enhancement of tumor necrosis factor production in peritoneal macrophages and splenic T lymphocytes. Microwave exposure affected T cells, facilitating their capacity to proliferate in response to mitogenic stimulation. The irradiation duration necessary for the stimulation of cellular immunity ranged from 5 h to 3 days.
Chronic exposure for 7 days produced the decreasing of tumor necrosis factor production in macrophages.
The irradiation of the animals for 24 h increased the tumor necrosis factor production and immune proliferative response, and these stimulatory effects persisted over 3 days after the termination of exposure.
Microwave treatment increased the endogenously produced tumor necrosis factor more effectively than did lipopolysaccharide (one of the most potential stimuli of synthesis of this cytokine).

Study character:

Study funded by

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