Epidemiological studies suggest that exposure to electromagnetic field
s (EMFs) in the environment may be associated with mutagenic changes,
but the relation between EMF exposure and aneuploidy has not previousl
y been studied. Environmental EMFs apparently lack the energy necessar
y to function as aneugens, but the possibility exists that EMFs could
influence the incidence of aneuploidy synergistically because EMFs can
activate the neuroendocrine system, and ovulation and oocyte meiotic
maturation are under neurohormonal control, This hypothesis was tested
by examining the effect of EMF exposure on the occurrence of hyperplo
idy in mouse oocytes induced by vinblastine sulphate (VBS), which was
employed as a surrogate for aneugens in the environment. The incidence
of hyperploidy in metaphase II oocytes of individual mice following s
uperovulation was determined, and statistical methods were developed t
o assess whether EMF exposure during oogenesis in the presence of VBS
altered the rate of hyperploidy. A significant effect of EMF exposure
on VBS-induced hyperploidy was found (P < 0.05), The data suggested th
at the EMF primarily affected the mice that exhibited a high incidence
of VBS-induced hyperploidy, Exposure had no effect on the number of o
ocytes ovulated nor on the occurrence of hypoploidy. The results suppo
rt the hypothesis that EMF exposure can promote the occurrence of aneu
ploidy caused by an aneugen via a mechanism involving the neuroendocri
ne system.