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Bioelectromagnetism

is aimed at health risk assessment, it also focuses on whether electromagnetic felds have efects on liv­

ing organisms, animal, and plants. Te earth itself is a large magnet and generates geomagnetic feld.

Magnetic bacteria and organisms such as honeybees, pigeons, migratory birds, salmon, etc. are known

to utilize geomagnetism. On the other hand, superconducting magnets are used in magnetic resonance

imaging (MRI) systems in the medical feld. In this way, the opportunities for people to be exposed to

DC magnetic felds have been steadily increasing.

Based on the fndings from the health risk assessment of the WHO project, exposure guidelines due

to scientifcally established interactions between electromagnetic felds and living organisms have been

considered.

Tere have been safety guidelines to protect excessive human exposure to electromagnetic felds

(EMF) developed based on reproducible and scientifcally established fndings of biological efects.

Widely recognized guideline setting bodies worldwide are International Commission on Non-Ionizing

Radiation Protection (ICNIRP) and Institute of Electrical and Electronics Engineers (IEEE/ICES).

Tese guidelines have been used as a scientifc basis for evaluating the human safety of electromagnetic

felds encountered in real living or industrial environments. Outlines of the guidelines developed by

these organizations are described in the following sections.

ICNIRP and IEEE/ICES have been introducing exposure limits, respectively, as guideline/stan­

dard based on scientifc fndings. Guidelines for limiting exposure to electromagnetic felds issued by

ICNIRP are ofen used as the basis for national regulations. ICNIRP issued a guideline covering time-

varying electromagnetic felds up to 300 GHz in 1998 (ICNIRP, 1998). Since then, guidelines have been

revised, with guidelines for 1 Hz to 100 kHz issued in 2010 (ICNIRP, 2010), and guidelines for 100 kHz

to 300 GHz in 2020 (ICNIRP, 2020). For DC magnetic felds, guidelines were issued in 2009 (ICNIRP,

2009). IEEE/ICES have published IEEE standards (IEEE C95.1-2019) covering frequencies up to 300 GHz

in 2019 (IEEE, 2019).

7.2 Electromagnetic Fields

According to ICNIRP statement, non-ionizing radiation refers to electromagnetic radiation and felds

with photon energy lower than 10 eV, which corresponds to frequencies lower than 3 PHz (3 × 10¹⁵ Hz).

Te groups of static and magnetic felds (0 Hz), low frequency (LF) electromagnetic felds (1 Hz to

100 kHz), and radiofrequency (RF) electromagnetic felds (100 kHz to 300 GHz) are categorized into

non-ionizing radiation. Ultraviolet (UV) radiation (wavelengths 100–400 nm), visible light (wavelength

400–780 nm), and infrared radiation (wavelengths 780–1,000 nm) are also grouped into non-ionizing

radiation (ICNIRP, 2020a). Ionizing radiation causes damage to living organisms through ionization

and excitation and its efect on genes is major problem. On the other hand, light such as ultraviolet,

visible light, and infrared radiations, which are classifed as non-ionizing radiation, has weak penetra­

tion to living organisms and is not harmful to them. For example, the near-infrared light penetrates

relatively well into the body. So it is used for example detection of biological information, such as pulse

oximetry, for safety reason.

Exposure to non-ionizing radiation is ubiquitous in our everyday life. Tere are natural sources of

non-ionizing radiation generating from the earth’s magnetic feld (geomagnetic feld), lightning storms,

and the sun. Man-made non-ionizing radiation exposures in the environment include LF electric and

magnetic felds from power supply and distribution infrastructure, RF felds from telecommunications

and other radio transmissions.

7.2.1 Static Fields

Static electric and magnetic felds at 0 Hz are naturally found in the earth’s atmosphere including the

geomagnetic feld. Man-made static felds occur commonly in transportation, industry, and medicine.

Tere has been a lot of research on whether exposure to static and LF felds cause any health efects. Most