Study type: Medical/biological study (experimental study)

Changes in the dielectric properties of rat tissue as a function of age at microwave frequencies. med./bio.

Published in: Phys Med Biol 2001; 46 (6): 1617-1629

Aim of study (acc. to author)

The dielectric properties of ten rat tissues at six different ages (new-born, 10, 20, 30, 50, and 70 days old) were measured in the frequency range of 130 MHz to 10 GHz.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 130 MHz–10 GHz -

Exposure 1

Main characteristics
Frequency 130 MHz–10 GHz
Type
Exposure setup
Exposure source
Setup The dielectric properties of ten rat tissues at six different ages were measured using an open-ended coaxial probe and a computer controlled network analyser, following a procedure described in the reference article. Small probes of 2.2 mm (radius 0.256 and 0.838 mm) and 3.5 mm (radius 0.456 and 1.49 mm) were used. The sample thickness was at least four to five times the probe diameter.
Additional info Measured data are reported for 900 and 1800 MHz (GSM) and for 2 GHz (UMTS) as well as for 1 GHz (brain only). Data above 600 MHz were fitted to the Cole-Cole expression and the results are shown in a table.
Parameters

No parameters are specified for this exposure.

Reference articles

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The data showed a general decrease of the dielectric properties with age. The trend is more apparent for brain, skull and skin tissues and less noticeable for abdominal tissues. The variation in the dielectric properties with age is due to the changes in the water content and the organic composition of tissues.
These results provide an important input in the provision of rigorous dosimetry in lifetime-exposure animal experiments. The data provide some insight into possible differences in the assessment of exposure for children and adults.

Study character:

Study funded by

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