Study type: Medical/biological study (experimental study)

The 1.5 GHz electromagnetic near-field used for cellular phones does not promote rat liver carcinogenesis in a medium-term liver bioassay. med./bio.

Published in: Jpn J Cancer Res 1998; 89 (10): 995-1002

Aim of study (acc. to author)

A previous study showed that local exposure to 929.2 MHz electromagnetic near-field, used for cellular phones, does not promote rat liver carcinogenesis in a medium-term bioassay system. In the present study, a 1.439 GHz electromagnetic near-field (EMF), another microwave band employed for cellular phones, was similarly investigated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.439 GHz
Modulation type: pulsed
Exposure duration: repeated daily exposure for 90 min/day, 5 days/week, over 6 weeks
  • power: 0.33 W average over time (antenna input)
  • SAR: 0.68 W/kg average over mass (whole body) (0.680-0.453 W/kg)
  • SAR: 1.91 W/kg peak value (partial body) (1.91-0.937 W/kg in the liver)
  • SAR: 7.6 W/kg peak value (whole body) (6.20-7.60 W/kg in other tissues)

Exposure 1

Main characteristics
Frequency 1.439 GHz
Type
Charakteristic
Exposure duration repeated daily exposure for 90 min/day, 5 days/week, over 6 weeks
Modulation
Modulation type pulsed
Duty cycle 33 %
Repetition frequency 50 Hz
Additional info

PDC modulation (Japanese cellular telephone standard)

Exposure setup
Exposure source
Distance between exposed object and exposure source 1 cm
Chamber A total of 12 exposure boxes with the antenna located at the centre of the bottom were placed in separate rooms.
Setup Animals were held individually in a narrow plastic cylinder (55 mm or 70 mm diameter) with ventilation holes. Two cylinders were placed on either side of the antenna.
Additional info Animals were given a single injection of diethylnitrosamine two weeks before exposure to initiate hepatocarcinogenesis. Animals for sham exposure were treated the same way as animals in the exposure group but without EMF. Animals in the control group were not placed in the cylinders or exposure boxes.
Parameters
Measurand Value Type Method Mass Remarks
power 0.33 W average over time - - antenna input
SAR 0.68 W/kg average over mass calculated whole body 0.680-0.453 W/kg
SAR 1.91 W/kg peak value calculated partial body 1.91-0.937 W/kg in the liver
SAR 7.6 W/kg peak value calculated whole body 6.20-7.60 W/kg in other tissues

Reference articles

  • Imaida K et al. (1998): Lack of promoting effects of the electromagnetic near-field used for cellular phones (929.2 MHz) on rat liver carcinogenesis in a medium-term liver bioassay.

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 study indicated that local exposure under the experimental present conditions has no promoting effect on rat liver carcinogenesis. Despite increased levels of corticosterone, adrenocorticotropic hormone (ACTH) and melatonin, the numbers and the areas of GST-P-positive foci were not significantly altered by the exposure.

Study character:

Study funded by

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