Teratological studies of prenatal exposure of mice to a 20 kHz sawtooth magnetic field

Abstract

In order to evaluate the importance of gestational age in possible effects due to exposure to a 20 kHz sawtooth magnetic field, pregnant ICR mice at gestational 2.5-15.5 days post-coitus, which is the most sensitive stage for the induction of major congenital malformations, were exposed in a carrousel irradiator. The mice were exposed to a 20 kHz intermediate frequency (IF) sawtooth magnetic field had a 6.5 microT peak intensity for 8 h/day. The animals were sacrificed on the 18th day of gestation; and the fetuses were examined for mortality, growth retardation, changes in head size, and other morphological abnormalities. From the above conditions, it is concluded that the exposure to a 20 kHz sawtooth magnetic field with 6.5 microT peak intensity does not inflict any adverse effect on fetuses of pregnant mice.

The Effect of Electromagnetic Fields with the Mg<sup>2+</sup> Cyclotron Frequency on Mouse Reproductive Performance

“…Consistent with reports in the literature, the observed changes were sporadic and did not affect organogenesis in the offspring [17]- [22]. Table 2.…”

Teratological evaluation of mouse fetuses exposed to a 20 kHz EMF

“…We previously investigated the effect of IF-EMF at a 6.25 mT peak intensity, and found no adverse effect on the fetuses of pregnant mice [Kim et al, 2004]. Therefore, in this study we examined IF-EMF of a 20 kHz magnetic field with a 30 mT peak intensity, which is the limit standard for occupational population.…”

“…Previous results from laboratory animal studies suggest that IF disturbed the development of animal embryos [Berman et al, 1990;Farrell et al, 1997;Youbicier-Simo et al, 1997]; however, the results have been inconsistent [Juutilainen, 1991;Chernoff et al, 1992;Brent et al, 1993;Huuskonen et al, 1998a] and most studies conducted in mammals reported no or only slight effects on fetus [Tribukait et al, 1987;Stuchly et al, the fetal development of pregnant mice, regardless of gestational age. Consequently, for our current study, we increased the peak intensity of 20 kHz EMF to 30 mT, which is the limit standard for occupational population at 20 kHz in Korea [Yoo, 2002;Kim et al, 2004].…”

“…In several previous experiments, pregnant rats or mice have been exposed to sinusoidal 50-60 Hz MFs at intensities ranging from 2 mT-30 mT or to 15-20 kHz fields with a sawtooth waveform ranging from 5.7 to 66 mT [Tribukait et al, 1987;Stuchly et al, 1988;Wiley et al, 1992;Frolen et al, 1993;Huuskonen et al, 1993;Kowalczuk et al, 1994;Mevissen et al, 1994;Ryan et al, 1996;Huuskonen et al, 1998a;Kim et al, 2004]. Our results also suggested that the IF dose used for our experiments did not induce any gross malformations, which is consistent with several other studies which found no evidence of teratogenic or embryotoxic effects subsequent to IF exposure.…”

“…A 2-axis magnetic field exposure equipment [Kim et al, 2004] designed to produce a magnetic field strength of 30 mT was used in this study. Although the coils were biaxial, only the horizontal coils were used (B field vertical).…”