An evaluation of the teratogenic potential of protracted exposure of pregnant rats to 2450‐MHz microwave radiation: I. Morphologic analysis at term

Abstract

The present investigation was designed to study the effects of protracted prenatal exposure of rats to a 20-mW/cm2 power density level of microwave radiation at a frequency of 2450 MHz. Preliminary studies using 24 rats indicated that this power density level did not cause a significant increase in maternal body temperature as measured by a rectal thermocouple. Of 75 pregnant rats, 12 were exposed to microwave radiation, 4 sham-irradiated, and 59 used as environmental control animals. Rats were exposed throughout pregnancy for a total exposure time of approximately 270 h. Daily maternal weights were recorded before irradiation. At term animals were killed, selected maternal tissues were removed, and fetal and placental positions and weights were recorded. After fixation for at least 3 wk, 462 term fetuses were dissected and examined for abnormalities. No significant alterations were observed for the following parameters: maternal weight gain during pregnancy, term maternal organ weights (brain, liver, kidneys, ovaries), term fetal weight, resorption rate, or abnormality rate. These results indicate that the protracted exposure of pregnant rats to 2450-MHz microwave radiation at a power density level of 20 mW/cm2 is not embryopathic.