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The Coupling of Atmospheric Electromagnetic Fields

FIGURE 3.8 Efects of presence or absence of 10Hz electric feld on changes in free-running circadian rhythms

in subjects under constant conditions. Te hatched section is the period of 10 Hz electric feld exposure. Activity

rhythm is shown by bars (black flled = active period, white flled = resting period), body temperature rhythm, (▲)

represent maxima and (▽) minima. Open triangles represent the temporal repetition of the maximum and mini­

mum. Period (τ) represents the various phases of the experiment. (From Wever, 1968.)

control subjects who were not aware of diferences between two rooms. One room was shielded from

electromagnetic felds (reduction of natural static electric feld) and the other is installed with a vertical

10 Hz, 2.5 V/m electric felds, which was almost equivalent to that in the natural environment (SR signal).

Human circadian rhythm has been studied in an underground room shielded from natural electric and

magnetic felds. It also appears sensitive to 10 Hz, 2.5 V/m electric feld imposed in this shielded environ­

ment (Wever, 1968, 1973, 1974, 1975, 1977).

Te period of the free-running circadian rhythm became shorter and returned to its original length,

when the electric feld was terminated. As an example, Figure 3.8 demonstrated the change of free-

running circadian rhythm. Subjects were then exposed to a 10 Hz, 2.5 V/m electric feld in the shielded

room. Te 10 Hz feld was of during frst and third periods in Figure 3.8. When the feld was turned on

during the second period, the period of free-running rhythm shortened. During the third period with

turn of, the period of rhythm lengthened and internal desynchronization occurred.

Totally ten experiments show that the period was shorter with the 10 Hz feld than without it by an

average of 1.3 ± 0.7 hours with highly signifcant level (p < 0.001) (Wever, 1974). Te shortening was greater

for those subjects with the longest circadian cycles in the absence of the feld. Te internal desynchroni­

zation was not observed when the electric feld was applied. In some subjects internal desynchronization

occurred immediately afer the feld was switched of; in others it ceased immediately afer the feld was

switched on. Tis showed that a 10 Hz electric feld can afect circadian rhythms, including shortening the

period and minimizing internal desynchronization. Reducing feld exposure to 12 hours on and 12 hours

of did not eliminate its Zeitgeber efect in temporarily restoring a 24.0 hour rhythm in ten subjects with

free-running rhythms between 23.5 and 26 hours. Wever interpreted these results as indicating a signif­

cant Zeitgeber capacity of the 10 Hz feld even when imposed intermittently (Wever, 1970, 1974).

Free-running period was measured by the activity and rectal temperature periodicities in initial

experiments. In the unshielded room, subjects had free-running period shorter on the average by 20

minutes, and internal desynchronization was less likely than in the shielded room (unshielded room:

n = 57, mean free-running period 24.87 ± 0.45 hours, internal desynchronization in four subjects;

shielded room: n = 80, mean free-running period 25.21 ± 0.80 hours, internal desynchronization in 28

subjects). All these diferences were signifcant at P < 0.01. Wever hypothesized that the diferences were

due to natural electromagnetic feld present only in the unshielded room (Wever, 1970).