Study type: Medical/biological study (experimental study)

Lack of promotion of 7,12-dimethylbenz[a]anthracene-initiated mouse skin carcinogenesis by 1.5 GHz electromagnetic near fields. med./bio.

Published in: Carcinogenesis 2001; 22 (11): 1837-1841

Aim of study (acc. to author)

To study the effects of 1.5 GHz electromagnetic near fields of TDMA signal on mouse skin carcinogenesis initiated by 7,12-dimethylbenz[a]anthracene (DMBA).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.49 GHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 90 min/day, 5 days/week for 19 weeks
  • SAR: 2 W/kg maximum (skin local peak)
  • SAR: 0.084 W/kg average over mass (whole body)

Exposure 1

Main characteristics
Frequency 1.49 GHz
Type
Charakteristic
Exposure duration repeated daily exposure, 90 min/day, 5 days/week for 19 weeks
Modulation
Modulation type pulsed
Duty cycle 33 %
Repetition frequency 50 Hz
Additional info

TDMA signal for the PDC system

Exposure setup
Exposure source
  • monopole
Distance between exposed object and exposure source 3 mm
Chamber Each mouse was placed in an aluminium box that was covered inside with RF absorber (< -21.8 dB at 1.5 GHz) except for the roof and the front door. The front door was a new type of transparent (20 dB) absorber. Forty-eight exposure boxes were used (24 for EMF and 24 for sham exposure).
Setup The EMF was directed at the mouse skin by an electrically short monopole antenna with capacitive loading, implemented using a circular metal plate (7 mm diameter, 1 mm thick) attached to the tip of a 1/8-wavelength monopole element, and producing highly localized peak SARs. The roof of the box acted as the ground for the antenna. The mouse was held in a ventilated plastic cylinder with a slit at the top allowing a distance of only 3 mm between skin and antenna.
Additional info One week after being subjected to topical application of DMBA on pre-shaved dorsal skin the mice were divided into four groups, receiving EMF exposure, sham exposure, weekly topical applications of TPA as positive control and no treatment as carcinogen control.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg maximum measured and calculated - skin local peak
SAR 0.084 W/kg average over mass measured and calculated whole body -

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 results demonstrated that near field exposure to 1.5 GHz electromagnetic field, used for cellular phones, does not exert any enhancing effect on skin tumorigenesis initiated by DMBA.

Study character:

Study funded by

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