Effects of high and low gradient magnetic fields on human performance for space flight application

Busby, D. E.

English

NASA Technical Reports Server

4.
IVIAGNET IC FIELDS
in future space operations, astronauts may be exposed to a very wide
range of magnetic field intensities and gradients. Figure 4-I presents
magnetic field intensities expected at several points in the solar system.
It suggests that field intensities on the lunar surface will be several orders
of magnitude less than the geomagnetic field. At a distance of more than
i0 Earth radii, the solar wind is expected to have a magnetic field of only
i0-4 to 10 -5 gauss (I_). Intricacies of the interaction between the solar
SUN
JUPITER? SURFACE MOON
EXPERIMENTAL FLANE EARTH S'n_bl'_ _lE'r
)
RANGE OF PRESENT
810MAG NE T _C FXpE RIMENTAT ION
Figure 4-1
Range of Magnetic Field Intensities
(After Beischer (8))
wind, magnetic fields, and trapped radiation belts around the Earth, are
being unraveled ( Z, 26, Z7, 29, 33 ). A neutral sheet or wedge of low
field strength is present on the down-Earth side of magnetosphere. The
surface of Venus probably has intensities of less than 0.05 gauss and Mars,
even lower values. While the solar photosphere has a field strength of
i gauss, the center of sunspots have been calculated to range from 1000 to
3500 gauss. The contribution of electronic equipment on board a space
vehicle to the total magnetic field experienced by an astronaut both extra-
and intra-vehicularly is not clear (15).
The high-gradient magnetic fields with intensities of several tens of
thousands gauss suggested for anti-radiation shielding and electric propulsion
systems may, in some instances, be involved in human exposure (14, 15, 25 ).
Relatively little is known about the specific effects of high and low inten-
sity magnetic fields on man ( 1, 7, 8, 9, ii, 15, ZZ ). Past studies in
magneto-biology have been directed mainly at determining the effects of
magnetic fields different from that of the geomagnetic field on sub-human
species, plants, and simple chemical systems. Several reviews of these
background materials are available (I, 3, 5, 7, 8, 9, ii, 15, 19, 22, 311.
Low Magnetic Fields
Very few human exposures to a magnetically quiet environment have been
reported. A certaxn amount of experience has accumulated during ordnance
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work inside degaussing coils. A health survey of personnel exposed to an
almost magnetically quiet environment during most of their working day
over several years revealed no ailment traceable to this unusual environ-
mental exposure ( II ). A number of physiologic and psychologic studies on .
two men exposed for 14 days to a magnetic field of about 50 gamma (l gamma i.
= 10-5 gauss) revealed no abnormal responses ( 9, Ii ). A similar study of _
low gauss in which six men were exposed to a magnetic field below 50 gamma _i
revealed significant alterations in scotopic critical flicker fusion and bright- iiii_ i._ •
ness discrimination in five of the six subjects during the period of exposure ......
" " 4,
( I0, 13 ). Such limited observations suggest that some physiologic processes ....
of the human may be altered in the geomagnetic and lunar magnetic fields, _...._, • _
but more experimental work is required before the operational significance i lii. _
of these findings is known ( 15 ).
The view is generally held that during the millions of years life was
evolving in our planet, the general magnitude of the Earth's magnetic field
was no different from that measured at the present time (4 ), though its
polarity and strength have detectably changed several times, the last major
change occuring about 7 x 105 years ago ( 20, 28 ). Accordingly, it is not
unreasonable to assume that living creatures have become accustomed to
the geomagnetic field as part of their natural habitat, and possibly that some
biologic processes have actually become to some degree dependent on the
presence of the geomagnetic field ( 4 ). It has been pointed out that normal
magnetobiologic effects would take place on molecular and atomic levels ( 8 ).
It is suggested that a turn of the human body in the geomagnetic field imparts
a momentary precession, according to the Larmor theorem, of approximately
2000 cps to all hydrogen nuclei in the body. Other magnetic cell constituents
should also precess with frequencies according to their mechanical and
magnetic moments. One must consider that the near absence of precession
movements in very low intensity magnetic fields may deprive living matter of
spatial clues, and that very careful long-term physiologic and psychologic
observations of man in such fields are necessary before predictions that
human performance will be unaltered under such conditions (15).
I
Few data are available on the magnetic fields encountered within a typical ....
spacecraft cabin. The induced magnetic fields at different distances from -
specific electronic components and the magnetic characteristics of represen-
tative spacecraft materials have been recorded (17 }. Such data are of value ' •
in design of magnetic field experiments in orbit or on the lunar surface.
High Magnetic Fields
What is presently known of the effects of high magnetic fields on man is
summarized in Table 4-Z. These responses were obtained from personnel
of a number of nuclear physics laboratories who are exposed occupationally
to high magnetic fields.
This list should not be taken to mean that the performance of man will
not be degraded in high magnetic fields. There is every indication from
recent studies using spider monkeys as subjects that very high magnetic
fields Cup to I00,000 gauss for Z4 hrs.) may affect neural and cardiac
4-2
Table 4-2
Effects of Magnetic Fields on Man
(After Beischer (9))
VISUAL SENSATIONS (PHOSPHENES) IN ALTERNATING FIELD.
NO SENSATION OBSERVED IN PART AND ENTIRE BODY EX-
POSURE TO NON-CHANGING FIELDS UP TO 20 kilogauss
FOR A DURATION OF 15 MINUTES.
NO AFTER-EFFECTS FOLLOWING EXPOSURE TO FIELDS OF
5 kilogauss FOR LESS THAN 3 DAYS PER YEAR PER MAN.
TASTE AND PAIN SENSATION CAUSED BY INTERACTION WITH
FILLINGS OF TEETH SOMETIMES DESCRIBED.
-.4. _-. • •
ii_., .A_.¸ _ •
i_:: •i• ! :•_
function ( 12, 13, 23 ). These studies demonstrated a shift of the frequency
of the EEG to higher values and a considerable increase in intensity of the
brain potential. The electrocardiogram showed a decrease in heart rate, an
increase in sinus arrhythmia and an augmentation of the amplitude of the T
wave. No gross pathology has been seen in these animals. The significance
of such alterations to the general health and psychomotor performance of
humans remains to be determined.
Exposure of animals, isolated organs, neoplastic and non-neoplastic
tissue cultures and simple chemical systems to high magnetic fields has
produced a great variety of biologic effects (15). To date, no definite
magnetic dose-effect relationship has been established. Effects have been
predicated on the basis of field strength alone ( 9 ), as well as on the
inhomogeneity of the paramagnetic strength of the field ( 4 ).
The coupling of magnetic fields with biological systems has been hypothe-
sized as due to(4, 6, 18, 24, 29, 32):
1)
2)
3)
4)
5)
6)
Generation of electromotive force in moving conductors.
Force exerted upon moving charge carriers at critical sites ( 24 ).
Torque exerted on permanent magnetic dipoles and non-
spherical para- or diamagnetic particles (29).
Retarding effect on the rotational diffusion of large molecules,
leading to a decrease in biochemical reaction rates.
Alteration of bond angles, which may influence chemical
reaction rates (24).
Alteration of tunneling rate of protons in hydrogen bonds of
mac romolecular systems.
4-3
Any one of these basic factors could possibly alter human performance
under very high magnetic fields. Much work is required to classify the
mechanisms responsible for behavioral changes in animals exposed to these
fields (15, 21 ).
There is a deficiency of data on electromagnetic fields in which the
electro and magnetic components are strongly perturbed. Checklists of
sources of different electromagnetic radiations are available (34).
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4-2.
4-3.
4-4.
4-5.
4-6.
4-7.
4-8.
4-9.
4-10.
REFERENCES
Alexander, H. S., Biomagnetics - The Biological Effects of
Magnetic Fields, Amer. J. Med. Electron., 2: 181-187,
July-Sept. 196Z.
Axford, W. I., Petschek, H. E., Siscoe, G. L., Tail of the
Magnetosphere, ft. Geophys. Res., 70: 1231-1236, 1965.
Barnothy, J. M., Biologic Effects of Magnetic Fields, • __inMedical
Physics, Vol. Ill, Glasser, O., (ed.), The Year Book
Publishers, Inc., Chicago, 1960, pp. 61-64.
Barnothy, J. M., Introduction, in Biological Effects of Magnetic
Fields, Barnothy, M. F.,-'_d.), Plenum Press, N. Y.,
1964, pp. 3-24.
Barnothy, M. F., {ed.), Biological Effects of Magnetic Fields,
Plenum Press, N. Y., 1964.
Barnothy, M. F., A Possible Effect of the Magnetic Field upon
the Genetic Code, in Biological Effects of Magnetic Fields,
Barnothy, M. F.,-_d.), Plenum Press, N. Y., 1964, pp.
8O-89.
Becker, R. O., Relationship of Geomagnetic Environment to
Human Biology, N. Y. State J. Med., 63(Pt. Z): 2215-2219,
Aug. 1963.
Beischer, D. E., Biological Effects of Magnetic Fields in Space
Travel, in XIlth International Astronautical Congress,
Washingto---n, D. C., 1961, Baker, R. M. L., Jr. and
Makemson, M. W., (eds.), Academic Press, N. Y., 1963,
pp, 515-525.
Beischer, D. E., Biomagnetics, in Lectures in Aerospace
Medicine, School of Aerospac---e Medicine, Brooks AFB,
Texas, Feb. 4-8, 1963, pp. 367-386.
Beischer, D. E., Do Earth and Lunar Magnetic Fields Have an
Effect on Man and Does Man Himself Exert Magnetic Forces?
Naval Aerospace Medical Inst., Pensacola, Fla., in
Preprints of Scientific Program, 37th Annual Meeting, Aero-
space Medical Association, Las Vegas, Nev., Apr. 18-21,
1966, pp. 6Z.
k
• = -.
4-5
4-11.
4-1Z.
4-13.
4-14.
4-15.
4-16.
4-17.
4-18.
4-19.
4-20.
4-ZI.
Beischer, D. E., Human Tolerance to Magnetic Fields,
Astronautics, 7(3)____j24-25, Mar. 1962.
Beischer, D. E., Knepton, J. C., Jr., Influence of Strong
Magnetic Fields on the Electrocardiogram of Squirrel
Monkeys (Saimiri Sci_reus), NAV-SAM-MR005. 13-9010-1-8,
Naval School of Aviation Medicine, Pensacola, Fla., 1964.
Beischer, D. E., Knepton, J. C., Jr., Kembro, D. V., Exposure
of Man to Magnetic Fields as Will be Experienced on the
Moon and Mars, Letter Rept. NASA Order No. R-39, Naval
Aerospace Medical Inst., Pensacola, Fla., 1967.
Bernert, R. E., Stekly, Z. J. J., Magnetic Radiation Shielding
Systems Analysis, AVCO-5278-AMP-134, Avco-Everett
Research Lab., Everett, Mass., 1964.
Busby, D. E., ]Biomagnetics. Considerations Relevant to Manned
Space Flight, NASA- CR- 889, Sept. 1967.
Cantarano, S., Mariani, F., Magnetic Field Measurements in
Interplanetary Space, ESRO-SR-4, European Space Research
Organisation, France, 1966.
Fuchs, R. A., Experimenter's Design Handbook for the Manned
Lunar Surface Program, HA-SSD-60352R, Hughes Aircraft
Co., Culver City, Calif., Jan. 1967, pp. 4-21. (Prepared
under NASA Contract NAS 8-20244).
Gross, L., Distortion of the Bond Angle in a Magnetic and Its
Possible Magnetobiological Implications, in Biological
Effects of Magnetic Fields, Barnothy, M.7., (ed.),
Plenum Press, N. Y., 1964, pp. 74-79.
Gualtierotto, T., Effects of a Steady Magnetic Field on Cerebellar
Centers for Equilibrium and Orientation, in XIIth Inter-
national Astronautical Congress, Washing_6-n, D. C., 1961,
Baker, R. M. L., Jr. and Makemson, M. W., (eds.),
Academic Press, N. Y., 1963, pp. 586-604.
Heirtzler, J. R., Hayes, D. E., Magnetic Boundaries in the
North Atlantic Ocean, Science, 157: 185-187, Jul. 14, 1967.
Kholodov, Yu. A., The Effect of Electromagnetic and Magnetic
Fields on the Central Nervous System, NASA-TT-F-465,
June 1967. (Translation of Vliyaniye Elektromagnitnykh
i Magnitnykh Poley na Tsentral'nuyu Nervnuyu Sistemu.
Academy of Sciences, USSR, Moscow, 1966).
_i!_/_
r
Z
4-6
4-ZZ.
4-23.
4-24.
4-25.
4-26.
4-27.
4-28.
4-29.
4-30.
4-31.
4-32.
Kholodov, Yu. A., Magnetobiology, JPRS-33321, Joint Publications
Research Service, Washington, D. C., Dec. 14, 1965,
(Translated from: Priroda, No. 10: IZ-21, Oct. 1965).
Knepton, J. C., Jr., Beischer, D. E., Possible Effects of Very
High Magnetic Fields on the Electronencephalogram of the
Squirrel Monkey (Saimiri Sciureus), Naval Aerospace Medi-
cal Inst., Pensacola, Fla. (Paper presented at the 37th
Annual Meeting of the Aerospace Medical Association,
Las Vegas, Nev., Apr. 18-21, 1966).
Kusabayashi, S., Laronge, T. M., Labes, M. M., Mechanisms
for the Effects of Electric and Magnetic Fields on Bio-
logical Systems, NASA-CR-91523, 1967.
Levy, R. H., Janes, G. S., Plasma Radiation Shielding, AVCO-
659-RR-192, Avco-Everett Research Lab., Everett, Mass.,
Sept. 1964.
Mackin, R. J., Jr., Neugebauer, M., (eds.), The Solar Wind
Conference Proceedings, California Institute of Technology,
Pasadena, Calif., Apr. 1-4, 1964, sponsored by Jet
Propulsion Lab., Pergamon Press, N. Y., 1966.
Ness, N. F., Earth's Magnetic Field: A New Look, Science,
151(3714): i041-1052, Mar. 1966.
Pitman, W. C., Heirtzler, J. R., Magnetic Anomalies over
the Pacific-Antarctic Ridge, Science, 154: I164-i171, Dec.
1966.
Roth, E. M., Response of Biological Atoms and Molecules to
Magnetic Fields, Lovelace Foundation for Medical
Education and Research, Albuquerque, N. M,, 1967.
(Prepared under NASA contract NASr-ll50 unpublished).
Scarf, F. L., Plasma in the Magnesosphere, NASA- CR-81759,
Dec. 1966. (Prepared for Vol. I of Advances in Plasma
Physics, Thompson, W., Simon, A., (eds.), Interscience
Press, N. Y.
University of Illinois, College of Pharmacy, Abstracts of papers
of the Third International Biomagnetic Symposium, Univ.
of Illinois, Chicago, Mar. 22-23, 1966.
Valentinuzzi, M., Rotational Diffusion in a Magnetic Field and
Its Possible Magnetobiological Implications, in Biological
Effects of Magnetic Fields, Barnothy, M. F.,---led. ),
Plenum Press, N. Y., 1964, pp. 63-73.
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d
• :< i•: ¸¸I _ i¸¸ • • :_-•,_ : ,
4-33.
4-34.
White, R. S., Synopsis of the Magnetosphere, in Lectures in
Aerospace Medicine, Sixth Series, School of Aerospace
Medicine, Brooks AFB, Texas, Feb. 6-9, 1967, pp.
401-426.
Zilitinkevich, S. I., Classification of Electromagnetic Wave
Sources, JPRS-43874, Joint Publications Research Service,
Washington, D. C., Jan. 1968. (Translation of News of
Higher Educational Institutions, Leningrad, 10(10): 13-17,
1967).
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