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Bioelectromagnetism

discovered by the French nuclear agency in 1972 (Kuroda, 1983), which showed that the nuclear “fre”

had existed on the earth and large-scale transmutations of the elements. Te Oklo had high concentra­

tions of uranium ore, about the same as those used in nuclear power plant today. Tis natural fssion

reactor is estimated to have reached criticality about two billion years ago and burned the equivalent of

about 30 kW of atomic energy over a long period of 150,000 years. Tis natural fssion reactor shows that

there were large amounts of highly radioactive rocks on the surface of the ancient earth. Terefore, the

radioactive environment on earth must have been severe. However, with the passage of more than a bil­

lion years, various types of radiation have gradually disappeared, and the present calm earth is thought

to have settled down.

All life on earth has also been exposed to cosmic rays pouring down from the far heavens. Fortunately,

cosmic rays are weakened by the infuence of the earth’s magnetic feld and ionosphere, but a certain

amount of cosmic rays always plow through the atmosphere and into biosphere. Biological systems

have survived and evolved in both the radiation generated by Earth’s rocks and radiation coming from

space. Radiation threatens life and generates mutations that have become the driving force of biological

evolution.

In addition to electromagnetic wave from the sun and radiation from the space and earth, living

organisms have been exposed to electromagnetic felds created by the earth itself, air ions, and electro­

magnetic felds of frequencies running around earth (ELF-electromagnetic felds: ELF-EMF) since the

beginning of life. In ancient times, when natural radiation was strong, the generation of air ions due to

ionization was much more intense than it is now. Tis may have had a signifcant impact on life. In the

era of tropical conditions and active geology, thunderclouds cause violent updrafs and volcanic explo­

sions were common, and the phenomena of electricity generation by lightning must have been much

more intense than today. Terefore, it is presumed that there were always strong static electric feld and

ELF-EMF on the earth. Tey must have had various efects on the evolution of life.

Te energy by electric, magnetic, and ELF-EMF is incomparably weaker than that of radiation. With

such low energy natural phenomena, it is assumed that organisms have been actively using that energy

to sustain life, rather than as a means of defense, such as an adaptive response. For example, geomagne­

tism is used in the migration of birds and fsh. Also, the static electric felds, air ions, seem to be closely

related to the growth and health of organisms. It is also speculated that ELF-EMF are closely related to

the formation of biological clocks that create the rhythm of life.

As factors of natural origin, various radiations such as cosmic rays, solar wind, X-rays, UV, visible

light, and IR that fall to the earth from outer space are known. Tese are caused by electromagnetic

phenomena in space. On the other hand, most of the phenomena on earth are lightning and electro­

magnetic phenomena in the ionosphere, and weather-related phenomena such as atmospheric pressure,

temperature, and various forms of water have important interactions with biological systems and ecol­

ogy. Tere are electric felds generated by electrical phenomena, magnetic felds generated by magnetic

phenomena, and electromagnetic waves that propagate in pairs in space. Te static electricity caused by

lightning is also an electromagnetic wave. In this way, there are many naturally occurring electromag­

netic waves around in our living space. Here, the relationship between these electromagnetic phenom­

ena and biological systems is briefy discussed.

3.3 Natural Background Fields

Te natural origins of the electromagnetic waves include the earth, the sun, atmosphere, and cosmic

phenomena. Te earth generates a magnetic feld. Lightning strikes occur in the atmosphere which pro­

duces the electric feld variation. Static electric felds are derived from the earth’s atmosphere as a part

of global electric circuit. Te naturally originated electric feld on earth is highest near the surface from

about 0.1 to 0.15 kV/m during fair weather conditions to several thousand V/m under thunderclouds.

The earth is a huge magnet. Its magnetic field is called the geomagnetic field. The intensity of geo­

magnetic field ranges from about 70 μT at the North and South Poles to about 30 μT on the equator.