Study type: Medical/biological study (experimental study)

No effects of radiofrequency radiation on 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone-induced tumorigenesis in female Wistar rats. med./bio.

Published in: Radiat Res 2006; 166 (2): 397-408

Aim of study (acc. to author)

To study possible effects of radiofrequency irradiation on tumorigenesis induced by the drinking water mutagen 3-chloro-4-dichloromethyl-5-hydroxy-2-5H-furanone (MX) in rats.

Background/further details

MX was given in the drinking water at a concentration of 19 µg/ml.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 2 h/day, 5 days/week, for 104 weeks
  • SAR: 0.3 W/kg mean (whole body) (0.07-0.65 W/kg)
  • SAR: 0.9 W/kg mean (whole body) (0.21-1.9 W/kg)

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 2 h/day, 5 days/week, for 104 weeks
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Repetition frequency 217 Hz
Additional info

continuous transmission of GSM pulses with a pulse period of 4.615 ms

Exposure setup
Exposure source
Chamber Nine well ventilated radial transmission line (RTL) exposure chambers were placed in three racks, each rack containing one exposure chamber for each of the three exposure conditions. Each exposure chamber consisted of two parallel circular aluminium plates with 150 cm diameter and 15 cm separation. The edges of the plates were shorted with a metallic wall covered with a ring of absorbing material to reduce reflections.
Setup Twenty-four ventilated polycarbonate cages having the shape of a truncated wedge (17 to 8.5 cm wide, 35 cm long, and 15 cm high), each containing an unrestrained rat, were placed symmetrically in the chamber with their wider end near the absorbing material. A tuneable monopole antenna at the center generated a radial plane wave. The EF was vertical (perpendicular to the plates) and the MF was circumferential, parallel to the plates.
Sham exposure A sham exposure was conducted.
Additional info Four groups of 72 animals each were treated as follows: cage control, MX + sham exposure, MX + 0.3 W/kg, and MX + 0.9 W/kg. The three chambers of each exposure group were always in different racks and at different rack levels.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.3 W/kg mean measured and calculated whole body 0.07-0.65 W/kg
SAR 0.9 W/kg mean measured and calculated whole body 0.21-1.9 W/kg

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Radiofrequency irradiation did not statistically significantly affect mortality or organ-specific incidence of any tumor type.
The only statistically significant difference was an increase in the merged vascular tumors of the mesenteric lymph nodes in the "high radiofrequency irradiation group" (0.9 W/kg) compared to the "sham exposure group". However, additional histopathological analysis of the cage control animals suggested that this difference was due to unusually low number of this type of tumor in the "sham exposure group" rather than a high number in the "high radiofrequency exposure group".
With respect to non-neoplastic findings, statistically significant differences between the "radiofrequency irradiation groups" and the "sham exposure group" were found only for single findings in the lacrimal glands, lungs, liver and skin. Such changes are commonly seen in aged rats and were considered to be unrelated to radiofrequency exposure.
The data do not support cocarcinogenic effects of low-level long-term radiofrequency exposure in rats.

Study character:

Study funded by

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