References on human body - electromagnetic field interaction 

Applications of magnetoquastistatic waves

 

 

Biological effects of exposure to static electric fields

 

https://ehjournal.biomedcentral.com/articles/10.1186/s12940-017-0248-y

Please refer to the first paragraph of section "Background" and the following excerpt.

 

"It is generally agreed that in contrast to static magnetic fields, static EF do not enter the body [14]. Based on the physics of field interactions with the body, the static EF within the body from an external source is attenuated by a factor of approximately 10−12 [16]. According to the current knowledge, static EF can cause effects on the body via changes in the distribution of electric charges on the surface of the body."

 

 

 

Electrostatic induction on the human body - Static electricity

 

"As one keeps walking across the floor, one becomes full of electrons"

Reading notes from references [1-3]*

 

Matter is normally electrically neutral because it consists of atoms which have zero charge, as the positive charge of the nucleus protons is neutralized by the negative charge of the electrons. Upon contact and friction of two materials, it is possible to induce charge separation (i.e. separation of positive and negative charges), flow of electrons from one material to the other and retention of an electron excess on one material versus the other. This phenomenon is known as static electricity. An example is represented by a person walking on a wool carpet with leather shoes. The contact and friction between the carpet and the floor causes a charge separation for each step, during which the shoes pick up extra electrons from the carpet.

 

The electrons spread on the surface of the body providing a negative charge to it (negative charge surface distribution). In other words, the body is being charged. The amount of charge that an entity can hold at a given voltage determines its capacitance (C=q/V). The capacitance of the human body is approximately 100 pF. The electron/negative charge build up can continue up to a very high voltage of 20.000 to 25.000 volts. This is a considerable value given that an electrical outlet supplies 110 to 240 volts. If the person reaches for a conductive object like a metal door knob, electrons will tend to flow from the body towards the door knob. The electrons due to collisions with the air molecules will generate ions and freed electrons and the air will become conductive as it is transformed to plasma which provides a bright spark.

 

In order to avoid static electricity, it helps to humidify the air. On humid days, a thin layer of water molecules covers most surfaces and this allows electrons to move freely and not accumulate (charge build up). Wrist straps connected to ground are used by electronic technicians and are recommended for earthing well-being practices. Also manufacturing plants may use ionizers to settle electronic behavior. An ionizer produces negatively charged ions such as O2- and N2- to which particulate air matter attaches.

 

References*

[1] https://www.livescience.com/4077-shocking-truth-static-electricity.html

[2] https://incompliancemag.com/article/static-electricity-and-people/

[3] https://en.wikipedia.org/wiki/Static_electricity

 

 

Electrostatic induction on the human body: Static and low frequency electric fields charge the human body surface (generation of positive ions - negative ions/free electrons)

 
References from the International Commision on Non-Ionizing Radiation Protection (ICNIRP)
 
STATIC ELECTRIC FIELDS 0 Hz
Effects of static electric fields on the body and health implications
 
"Static electric fields do not penetrate the human body because of its high conductivity. The electric field induces a surface electric charge, which, if sufficiently large, may be perceived through its interaction with body hair and through other phenomena such as spark discharges (microshocks). The perception threshold in people depends on various factors and can range between 10 - 45 kV/ m. Furthermore, very high electric fields, such as from HVDC lines, can charge particles in the air, including polluted particles."
 
LOW FREQUENCY 1 Hz - 100 kHz
"In addition, the LF electric field interacts with the surface charge of the body. At low levels, these interactions go mostly unnoticed, and do not compromise health."
 
"However, above a certain level of exposure, referred to as threshold, the induced internal fields provoke reversible effects on excitable cells in the body such as a faint light flickering in the periphery of the visual field (phosphenes); electric charge effects on the skin (similar to what is experienced when you comb your hair, causing your hair to rise); or a stimulation of nerves and muscles experienced as a tingling sensation. These effects occur at different thresholds depending on the frequency of the field."
 
This reference mentions additional effects such as the microwave auditory effect and the pearl-chain formation effect (e-page 64).
 
 

Additional references on human body - EM field interaction

 

1. From the book "Electromagnetic Fields in Biological Systems"
 
Coupling and distribution characteristics of low-frequency electric and magnetic fields in biological tissues
 
Coupling through ELF electric fields
Coupling through ELF magnetic fields

2. Please refer to three paragraphs following the hightlight at the link http://bit.ly/2nu8OE7 (including excerpt below).

The conditions of exposure at these frequencies in many situations, like power lines, are such that the sources of exposure are very distant to the human body and therefore can be considered uniform [16]. (Another note: http://bit.ly/2QDMmEs)

 

 

2. Please refer to p.48 (e-page 62) of "Exposure to high frequency electromagnetic fields, biological effects and health consequences (100 kHz-300 GHz)" by ICNIRP - International Commission on Non-Ionizing Radiation Protection
 
 

 

 

Navigation system using magnetoquasistatic waves: POINTER (Precision Outdoor and Indoor Navigation and Tracking for Emergency Responders) by the DHS and the NASA Jet Propulsion Laboratory (NASA JPL)

 

Waves generated by a dominantly magnetic electromagnetic source within a wavelength away

 

Factsheet and video from DHS site: https://www.dhs.gov/publication/st-frg-pointer-fact-sheet-and-video

Video features NASA JPL researcher Darmindra Arumugan describing the technology at 00:39 (cf. Figure)

 

Excerpt from his thesis (e-page 14) [pdf] http://bit.ly/2npvQMq


"A promising solution for position tracking in the presence of groups of people is the use of low-frequency, quasistatic magnetic fields instead of propagating radio waves. Quasistatic fields are in a sense an artifact of a region of nature within which we are allowed to decouple two fundamental laws of electromagnetism, namely Faraday’s law and Ampere’s generalized law (we will discuss this in more detail in Section 2)."

"For an electromagnetic source, this translates to a region surrounding the source, and depends strongly on the nature of the source. If the source is a dominant magnetic one, we use magnetoquasistatics to describe the nature of the fields created. Using a simple current loop, for example to create a dominant magnetic field, we create a magnetoquasistatic region within distances much less than a wavelength from the loop."

 

"At approximately a wavelength away from the source, Faraday’s law slowly couples with Ampere’s generalized law to give us the wave phenomena. Further than a wavelength away from the source, these laws become strongly coupled and the wave phenomena is dominant. Within the magnetoquasistatic region, the fields can be thought of as snapshots of static magnetic fields, and hence weakly conducting non-magnetic bodies such as the human body appear transparent to these magnetic fields, and thus will not disturb or distort these fields."

"Because the quasistatic region is defined well within a wavelength away from the electromagnetic source, a simple way of increasing the range of the quasistatic region is to reduce the oscillation frequency of the source (increase the wavelength). However, because a reduction in frequency corresponds to a reduction in voltage induced in a receiving antenna/loop, it is generally desirable to use the highest frequency consistent with the quasistatic condition for a specific application range. In many tracking applications, the range of frequencies for an ideal system is typically within 1 kHz and 1 MHz."