Medical/biological study (experimental study)

Interactive developmental toxicity of radiofrequency radiation and 2-methoxyethanol in rats med./bio.

By: Nelson BK, Conover DL, Shaw PB, Werren DM, Edwards RM, Hoberman AM

Published in: Teratology 1994; 50 (4): 275-293

The authors previously demonstrated that combined exposure to radiofrequency irradiation, which also induces hyperthermia and is teratogenic to exposed animals, and the industrial solvent, 2-methoxyethanol, produces enhanced teratogenicity in rats (see publication 3519).
The present study replicates and extends the previous research investigating the enhanced teratogenicity of combined radiofrequency irradiation and 2-methoxyethanol exposures. The interactive dose-related teratogenicity of radiofrequency irradiation was investigated by administering various combinations of radiofrequency irradiation and 2-methoxyethanol to groups of rats on gestation days 9 or 13; gestation day 20 fetuses were examined for malformations.

Exposure	Parameters
Exposure 1: 10 MHz Modulation type: CW Exposure duration: 0, 10, 20 or 30 min	SAR: 6.6 mW/g unspecified (set initially) SAR: 800 µW/g minimum (6.6 W/kg max value)

Modulation type	CW

Exposure source	not specified
Chamber	near field synthesizers enclosed within copper wire chambers housed in Forma 7010 or 74668 environmental chambers.
Setup	rats placed in cylinderical plexiglass holders with 12 mm holes
Additional info	Each rat was oriented in its long axis for induced EF to be parallel. Rats irradiated in one of the two RF-near field synthesizer facilities designed by NIOSH.

Measurand	Value	Type	Method	Mass	Remarks
SAR	6.6 mW/g	unspecified	-	-	set initially
SAR	800 µW/g	minimum	-	-	6.6 W/kg max value

Exposed system:

Investigated system:

Time of investigation:

The findings are consistent with and extend the previous research results. Synergism was found between radiofrequency irradiation and 2-methoxyethanol for some treatment combinations, but not for others. The study also clarified which gestational periods, radiofrequency irradiation durations, and 2-methoxyethanol doses would be most informative in future interaction studies to determine the lowest interactive effect level. Day 9 exposures generally evidenced little effect by 2-methoxyethanol, either by itself or in combination with radiofrequency irradiation. In contrast, day 13 exposures resulted in highly significant effects from 2-methoxyethanol and radiofrequency irradiation.

Study character:

Nelson BK et al. (1997): Interactions of radiofrequency radiation-induced hyperthermia and 2-methoxyethanol teratogenicity in rats
Nelson BK et al. (1997): Interactions of radiofrequency radiation on 2-methoxyethanol teratogenicity in rats
Nelson BK et al. (1991): Marked increase in the teratogenicity of the combined administration of the industrial solvent 2-methoxyethanol and radiofrequency radiation in rats