Study type: Medical/biological study (experimental study)

Effect of 2450-MHz radiation on the rabbit eye med./bio.

By: Guy AW, Lin JC, Kramar PO, Emery AF
Published in: IEEE Trans Microw Theory Tech 1975; 23 (6): 492-498
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Aim of study (acc. to author)

To investigate the effects of 2450 MHz microwave exposure in vivo on rabbit eye.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Exposure duration: up to 100 min

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Charakteristic
Exposure duration up to 100 min
Additional info horizontal polarization
Modulation
Modulation type unspecified
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.05 m
Setup Rabbits were placed in a acrylic box with the head fixed by a acrylic restrainer
Parameters
Measurand Value Type Method Mass Remarks
power density 150 mW/cm² unspecified measured - maximum SAR= 138 W/kg applied for 100 min
power density 300 mW/cm² unspecified measured - SAR= 270 W/kg for 30-35 min exposure
power density 200 mW/cm² unspecified measured - SAR = 180 W/kg for 35-40 min exposure
power density 1,000 W/m² unspecified measured - SAR= 90 W/kg; applied for 60 min
Measurement and calculation details

The incident power density was measured at the exact position position where the right eye was suppose to be located. It was measured with a Narda 8100 electromagnetic radiation monitor with the box and the head restrainer in place but the animal absent. The power delivered to the corner reflector antenna was monitored with a dual directional coupler and microwave power meters. SAR was determined by using thermocouple technique.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The main attention was to define a thermal threshold for cataractogenic microwave effects. After irradiation irreversible damage were only observed in the posterior cortical area of the eye lens. The minimum cataractogenic power density was 150 mW/cm2 for 100 min, which correspond to an SAR value of 138 W/kg in the vitreous body.
The study revealed a possible threshold temperature around 41°C. Furthermore the eye lens seems to be the most critical part of the eye to microwave irradiation. The findings of this study point to a thermal mechanism responsible for the observed microwave effects. However, the possibility of nonthermal effects of microwave radiation on eye should not easily rejected.

Study character:

Study funded by

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