Medical/biological study (experimental study)

An evaluation of the teratogenic potential of protracted exposure of pregnant rats to 2450-MHz microwave radiation. II. Postnatal psychophysiologic analysis med./bio.

By: Jensh RP, Vogel WH, Brent RL

Published in: J Toxicol Environ Health 1983; 11 (1): 37-59

Journal partially peer-reviewed/peer-review process unclear

Aim of study (acc. to author)

To study whether protracted prenatal exposure of rats to 2450 MHz microwave irradiation at a power density level of 20 mW/cm², which did not cause an overt increase in maternal body temperature, would significantly alter postnatal growth and psychophysiologic development.

Background/further details

Of 75 pregnant rats, 12 animals were exposed to microwave irradiation, four rats were sham exposed, and 59 served as control animals. The neonates were examined and weighed on day three and weekly thereafter until 87 days of age. Neonatal reflex tests were initiated as early as day three. One physiologic parameter, eye opening, was also observed. Mothers were rebred ten days after weaning and a morphological evaluation was completed on the second litter. Behavioral tests were begun at 60 d of age. At 90 days of age offspring were bred within and across groups, and a morphological teratologic analyses was completed on the offspring. Tissue samples were collected and organ weights were recorded of all animals.

Endpoint

effects on embryo/fetus: postnatal growth and psychophysiologic development/teratogenicity

Exposure

- 2.45 GHz
- microwaves

Exposure	Parameters
Exposure 1: 2.45 GHz Exposure duration: continuous, 6 h/day through gestation	power density: 20 mW/cm²

General information

The female pregnant rats (n=75) were divided in three groups: Group 1: n=12 exposed to microwave radiation, Group 2: n=4 sham-exposed, Group 3: n=59 environmental control

Exposure 1

Main characteristics

Frequency	2.45 GHz
Type	electromagnetic field
Exposure duration	continuous, 6 h/day through gestation
Additional info	In this report, exposure and measurement are not described in detail, but reference is made to the first part of the study (Jensh et al. 1983).

Exposure setup

Exposure source	anechoic chamber
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power density	20 mW/cm²	-	-	-	-

Reference articles

Jensh RP et al. (1983): An evaluation of the teratogenic potential of protracted exposure of pregnant rats to 2450-MHz microwave radiation: I. Morphologic analysis at term

Exposed system:

animal
rat/Wistar albino
whole body

Methods Endpoint/measurement parameters/methodology

effects on embryo/fetus: number of abnormal neonates; resorption rate; mean litter size; different behavioral and neonatal reflex tests (see "cognitive/behavioural endpoints"); morphologic teratogenic analysis (see "morphological/histopathological changes")
effects on the reproductive system: maternal fertility (number of neonates and resorption rate)
morphol./histopathol. changes: morphologic teratologic analysis
cognitive/behavioral endpoints: different neonatal reflex tests (e.g. auditory startle, visual placing (tests visual acuity)); behavioral tests (e.g. water T-maze, conditioned avoidance response, open field, activity wheel)
thermoregulation: rectal temperature of dams
body weight of dams and offspring; eye opening; maternal organ weight of brain, liver, kidneys, and gonads

Investigated system:

isolated organ
dead fetuses
investigation on living organism

Investigated organ system:

reproductive system
brain/CNS
eye, liver, kidneys, gonads, ovary, testis

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

The findings indicated that there were no significant malformations or significant alterations in the neonatal physiologic or reflex test results, body/organ weight ratios, or breeding results in the adult offspring. There were no significant changes in five of the six adult behavioral tests, but exposed offspring was significantly more active than control offspring.
These findings are indicative of possible irradiation-induced behavioral changes. Further investigations are needed to explore the possibility of microwave exposure-related changes in animal behavior.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

National Institutes of Health (NIH), Maryland, USA

Gathiram P et al. (2009): Effects of a unique electromagnetic field system on the fertility of rats
Saito K et al. (1991): Lethal and teratogenic effects of long-term low-intensity radio frequency radiation at 428 MHz on developing chick embryo
Jensh RP (1984): Studies of the teratogenic potential of exposure of rats to 6000 MHz microwave radiation. II. Postnatal psychophysiologic evaluations
Berman E et al. (1984): Decreased body weight in fetal rats after irradiation with 2450-MHz (CW) microwaves
Jensh RP et al. (1983): An evaluation of the teratogenic potential of protracted exposure of pregnant rats to 2450-MHz microwave radiation: I. Morphologic analysis at term
Inouye M et al. (1982): Effects of 2.45 GHz microwave radiation on the development of Japanese quail cerebellum
Berman E et al. (1982): Reduced weight in mice offspring after in utero exposure to 2450-MHz (CW) microwaves
Jensh RP et al. (1982): Postnatal functional analysis of prenatal exposure of rats to 915 MHz microwave radiation
Nawrot PS et al. (1981): Effects of 2.45 GHz CW microwave radiation on embryofetal development in mice
Berman E et al. (1981): Observations of rat fetuses after irradiation with 2450-MHz (CW) microwaves
Berman E et al. (1978): Observations of mouse fetuses after irradiation with 2.45 GHz microwaves