Absence of embryotoxic effects from low-level (nonthermal) exposure of rats to 100 MHz radiofrequency radiation.
Lary JM; Conover DL; Johnson PH
Scand J Work Environ Health 1983 Apr; 9(2):120-127
The embryotoxic or teratogenic effect of exposure to 100 megahertz (MHz) radiofrequency radiation was investigated in Sprague-Dawley- rats. Pregnant rats were irradiated to 100MHz radiofrequency under continuous wave in a transverse electromagnetic (TEM) transmission cell. Exposure to 100MHz was at a power density of 25 milliwatts per square centimeter for 6 to 40 minutes daily on each gestation day from days 6 to 11. Total exposure time was 40 hours, producing a body specific absorption rate of 0.4 watts per kilogram (W/kg). Animal weights and colonic temperatures were taken before and after radiation. Irradiation was done in a sham TEM cell to serve as a control. All rats were killed by cervical dislocation on gestation day 20, the uterine horns were examined for the number of implantations, live fetuses, and dead or reabsorbed fetuses. Live fetuses were further examined for several measurements including crown rump length and skeletal abnormalities. Specific absorption rate for radiofrequency power was determined by calorimetric method. There were no differences in maternal body weights between irradiated and sham irradiated rats any time during gestation period. No increase in maternal colonic temperature was produced by irradiation. No differences were observed between irradiated and sham irradiated rats with respect to the number of implantations per litter, percentage of dead or resorbed implantations, percentage of malformed fetuses, fetal weights, fetal crown rump lengths, or fetal sex ratios. The percentage of minor skeletal variations in live fetuses was significantly higher in the control group. The authors conclude that radiofrequency/microwave radiation has no teratogenic or embryotoxic effect on experimental rats at 0.4W/kg, the maximum permissible level.
NIOSH-Author; Radio-waves; Animal-studies; Pregnancy; Teratology; Microwave-radiation; Radiation-exposure; Biological-effects; Fetus; Embryotoxicity;
Author Keywords: fetus; hyperthermia; microwaves; specific absorption rate; teratogenesis
Dr JM Lary, Physical Agents Effects Branch, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA
Scandinavian Journal of Work, Environment & Health