nature, and to depend on the exposure level and duration. A single 10-minute exposure at 25 µW/cm2,
10 GHz, produced a decrease in the phosphorylation effectiveness factor (ADP/O) in liver
mitochondria, and an increase in respiratory control (RC) in kidney mitochondria (10). After ten such
exposures, the oxygen consumption and RC were both increased in kidney mitochondria. A single
exposure at 100 µW/cm2 caused a rise in oxygen consumption and an increase in ADP/O in liver
mitochondria and a decrease in RC in kidney mitochondria (10). After ten such exposures, almost all
the indices of oxidative phosphorylation in both mitochondria returned to normal, thereby suggesting
that the enzyme systems had adapted to the EMF. A decrease in RC was also seen in guinea pig
mitochondria exposed in vitro to 155 v/m, 60 Hz (11).
Rats were exposed to 10, 25, 50, 100, 500 and 1000 µW/cm2, at 2.4 GHz, as follows: 40
minutes per day, 3 times per day, 5 days per week, for 4 months (intended to simulate the exposure
received from household microwave ovens) (12). It was found that the EMF altered respiration and
phosphorylation in liver mitochondria; there was an increase of nonphosphorylating oxidation of
metabolites of the Krebs cycle, and a decrease in the oxygen consumption rates during phosphorylating
respiration. A decrease in oxygen consumption rate was also found after 20 days' exposure to 1000
µW/cm2, 46 GHz (13).
In a study of skeletal-muscle metabolism, rats were exposed to 300-900 gauss, 7 KHz for up to
6 months (1.5 hr./day) (14). Creatine phosphate and ATP levels decreased, and ADP levels increased
following exposure. The changes were consistent with both an increased energy requirement, and an
adverse effect on ATP formation. On the basis of in vitro studies of oxidative phosphorylation and
oxygen consumption involving tissues from the exposed animals, the authors favored the latter
possibility. Two consequences of the observed changes in cell bioenergetics involved carbohydrate and
nitrogen metabolism. Decreased glycogen levels were found, indicating a compensatory glycogenolysis
and, hence, an enhanced production of high-energy phosphate compounds. Secondly, EMF exposure
produced an increase in tissue ammonia levels with no corresponding increase in glutamine synthesis.
This may have been due to the ATP deficiency, although the influence of other factors involved in
glutamine production-glutamic acid and manganese for example-could not be excluded.
Shandala and Nozracher (15) reported that kidney function and water-salt metabolism in rabbits
(diuresis, chloride elimination, acid-base balance) were altered following the exposure to 50 and 500
µW/cm2, 2.4 GHz. In a comparable study (16), it was found that similar kinds of changes (urinary
levels of potassium, sodium and nitrogen) were sex dependent; most of the metabolite levels were
increased in females and decreased in males.
The altered nitrogen levels (16) suggested an EMF effect on protein synthesis. This was
confirmed by Miro et al. (17) who found that 160 hours' exposure of mice to 2000 µW/cm2, 3 GHz,
resulted in an increase in protein synthesis in the liver, thymus, and spleen as determined by
cytohistological techniques.
The most important study to date on lipid metabolism was performed by Dietrich Beischer and
his colleagues (18). Volunteers, confined for up to 7 days, were exposed to a 1-gauss magnetic field, 45
Hz, for 24 hours: they did not know which 24-hour period during their confinement would be chosen
for the application of the EMF. It was found that the serum triglycerides in 9 of 10 exposed subjects
reached a maximum value 1-2 days after EMF exposure (Fig. 8.1); similar trends were not seen in any
of the control subjects (18). Measurement of respiratory quotients for basal conditions established that
the hyperlipemia could not have been caused by a change in the proportion of fats and carbohydrates
being oxidized. Also, previous work had shown that confinement alone had no effect on serum
triglycerides. This suggested that the observed effect may have been due to a change in the activity of
ELECTROMAGNETISM & LIFE - 104