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Bioelectromagnetism

experiments, it was concluded that exposure of body surface area with hair could play a crucial role in

the detection of static electric felds.

Field perception experiments in human presented that detection thresholds for static electric feld

were signifcantly lower when the whole body was exposed compared to when only the subject’s arm

was exposed as partial body exposure. Te most reasonable reason for this diference is that whole-body

exposure increases the feld strength at the top of the body such as head or shoulders. In addition, per­

ception of static electric feld appears to be infuenced by several factors such as the relative humidity,

awareness, and simultaneous presence of air ions.

To identify the mechanisms of static electric feld, by recording action potentials from aferent fbers

innervating various sensory receptors in the anesthetized cat’s hindlimb, Kato et al. confrmed that

body hair is involved in the perception of static electric feld (1986). Tey recorded aferent impulse dis­

charges of hair receptors of cats exposed to static electric feld with 180–310 kV/m (both polarities). Te

stronger the electric feld, the wider was the angle of the hair movement. Action potentials were evoked

in the aferent fbers innervating G1 hair receptor, G2 hair receptor, and down hair receptor. No action

potentials were evoked in aferent fbers innervating type I, type II, feld receptors, muscle spindles, or

joint receptors. Teir results indicated that a strong static electric feld induced movement of the hairs,

eventually evoking excitation of the hair receptors.

In outdoor test under HVDC lines, most subjects do not detect electric felds below about 25 kV/m.

Clairmont et al. investigated human’s electric feld perception and thresholds for DC and AC electric

felds when HVAC and HVDC lines were operated in a hybrid fashion (1989). Each person rated various

sensations at measurement locations along the lateral profle of the test line, while DC feld, AC feld,

and ion current density were simultaneously monitored at each of the locations. When the DC and AC

electric felds overlapped, the threshold of the sensed electric feld was higher than when person was

exposed to each feld separately. However, it was pointed out that the number of subjects, their selection

methods, and characteristics have not been fully described. Tere are some shortcomings such as the

lack of sufcient description of the exposure conditions and the fact that it was not done in a double-

blind manner.

In long-term experiment, mice were continuously exposed to static electric feld (2 kV/m) during a

period of 2 years (Kellogg et al., 1985a, b, 1986). Tey found no diference in the lifespan of mice exposed

to 2 kV/m static electric feld (both polarity) and environmental static electric felds and that increased

values in serum glucose, and decreased urea nitrogen levels. Te authors saw a connection between

serum glucose levels and lifespan which lent support to their hypothesis that bioelectric processes are

involved in mortality and aging rate. On the other hand, the researchers from the Rockefeller University

found no efect on behavior or neurotransmitter activity in the brain of rats exposed to 3 and 12 kV/m

felds for 2, 18, and 66 hours (Bailey and Charry, 1986, 1987; Charry et al., 1985).

Exposure associated with DC transmission line includes static electric feld, static magnetic felds,

and air ion (charged aerosols). Tere are a wide variety of ions in the atmosphere (Reiter, 1992). Tese

ions originate from both natural such as cosmic rays, radioactivity, water splashing, etc., and high volt­

age transmission lines produced corona ions when the voltage of transmission lines are high enough to

cause corona breakdown around cable. In the past, as mentioned above, there were several investiga­

tions concerning the human perception of static electric feld. Subsequently, research on the efects of

air ions and static electric felds began in 1980, focusing on the problem of health efects of the electro­

magnetic environment under DC transmission lines.

Te new investigation will just start to identify the infuence factors to human perception of static

electric felds (Jankowiak et al., 2021). Tis research is focused on the infuence of experimental and

environmental factors such as the ramp slope, exposure duration, presence of air ions, and relative

humidity on human perception. It will provide preliminary insights into the studies of whole-body

static electric feld with a sufcient number of participants of all ages under highly controlled condi­

tions, which lead to determine statistically verifed detection thresholds. Tis will give the insights for

safety level of electric feld due to high voltage transmission lines. Using newly developed of DC and AC