254

Bioelectromagnetism

 

6.4 Health Effects of the Geomagnetic Field (GMF)

6.4.1 Magnetic Field Defciency Syndrome

It has been believed that some human energy is being absorbed from the GMF, so what if an MF reduc­

tion occurs on the Earth? A Japanese medical doctor, Kyoichi Nakagawa (Director of Isuzu Hospital)

has spent more than 20 years investigating the efects of MFs on humans. He pointed out that there is an

“MF defciency syndrome” likely caused by a decline in the GMF intensity in humans and the syndrome

can be corrected with the application of external MFs (Nakagawa, 1976). He noticed that the symp­

toms are stifness of the shoulders, back and neck, lumbago, chest pains, headache, dizziness, insomnia,

habitual constipation, general malaise, and so forth (Nakagawa, 1976). Nakagawa referred to scientifc

authorities who have proven that over the last two centuries the geomagnetic dipole strength has been

decreasing at a rate of ~6.3% per century (Merrill et al., 1996).

Here, the absolute magnitude of the axial dipole component of the GMF from 1600 to 2020 (Merrill

et al., 1996), according to three models—CALS3k.4 (Korte and Constable, 2011), gufm1 (Jackson et al.,

2000), and IGRF-12 (Tébault et al., 2015)—is shown in Figure 6.12. In this fgure, geomagnetic axial

dipole strength increased linearly from ~ 33 μT in 1,600 to ~ 35 μT by about 1,700, and then decreased

linearly and is now around 29.5 μT.

Moreover, together with the decrease of the GMF itself, Nakagawa pointed out that in modern indus­

trialized life, metal buildings, cars, trains, etc. could shield the GMF, causing interference and loss of the

GMF strength (Nakagawa, 1976). Terefore, living or working in steel frame or steel structure buildings

could decrease the efects of the GMF on the human body (Nakagawa, 1976). Nakagawa (1976) hypoth­

esized that if the GMF is artifcially shut out, there would be adverse changes in the central nervous

system and diurnal rhythm. Terefore, Nakagawa (1976) speculated that supplying the human body

with MFs by various methods would improve and alleviate physical complaints. He investigated the

therapeutic efects of stronger MFs (including SMFs and time-varying MFs) than the GMF, and found

that MFs improved some symptoms when MFs were externally applied, and advocated that the amelio­

rated disease is actually MF defciency syndrome (Nakagawa, 1976).

Tere is an average of 50 μT GMF, ranging from ~25 μT near the magnetic equator to ~65 μT at

the magnetic poles throughout the Earth, but not only is outer space weightless due to the absence

of gravity but also there is “almost no MF” outside the geomagnetosphere (Prölss, 2004). It is a well-

established fact that bone mass, bone mineral density (BMD), and bone mineral content (BMC) decrease

in the case of zero gravity. Jia et al. (2014) examined the physiological efects of “hypomagnetic feld

(HMF)” (<300 nT) on osteoporosis using animal models. Osteoporosis was induced in the femur by

FIGURE 6.12 Geomagnetic axial dipole strength from 1600 to 2020, according to three models: CALS3k.4,

gufm1, and IGRF-12. (Obtained from Wikimedia Commons, the free media repository. It is licensed under the

Creative Commons Attribution 4.0 International.)