gh GEOMAGNETIC FIELD IS NECESSARY FOR HEALTH

Geomagnetic field causes a lot of trouble to people. Disturbed field makes people take drugs and spoils the mood. Can there be any protection from geomagnetic field? What if a shield is set up for protection from magnetic field-related problems? It turns out that such protection can bring more harm than benefit. The consequences of isolation from natural geomagnetic field have been investigated via experiments with salmon fry by Oleg Zaporozhets, Doctor of Biology, Kamchatka Research Institute of Fish Industry And Oceanography.

Salmon fry raised for release into rivers are kept in large pools. Fish survival and growth rate depend on diverse factors: pool dimensions, water temperature and purity, food quantity and quality. However, there is one more factor which is normally disregarded, namely isolation from natural geomagnetic field. Geomagnetic field induction in the metal pools usually utilized at the fish-farm plants in Russia is several times less than in the natural environment, and gradients (dropping of electromagnetic characteristics) are thousands and even tens of thousands of times stronger. Concrete and plastic pools (which are normally reinforced with metal armature, surrounded by electric wires and are neighboring electric devices) decrease the induction level by 1.5 times on average as compared to that of the natural environment. Measurements have showed that the 50 Hz man-made statics occur in water in ferroconcrete pools, significant abnormalities were recorded even in the ordinary concrete containers - electomagnetic field hits exceeded the background level by hundreds of times and lasted for several seconds.

How does that impact the growing fry? It has turned out that protection from natural geomagnetic micropulsations helps the silversides fry (Oncorhynchus kisutch) survive at the very initial stages of development. However later, their death-rate increases by many times: due to the lack of physical conditioning the fry become the first candidates to die. As for the fry of another salmon species, Siberian salmon, the lack of natural geomagnetic field broke the fry's daily biorhythms, particularly of the fry raised in ferroconcrete pools: at night the fish got overexcitated, but were absolutely passive in the daytime. In the natural conditions, the difference between nocturnal and daily activity is much less and this is important: fish should always be on the alert as regards predators. Special experiments helped the researchers to find out that both salmon species raised in distorted electromagnetic conditions swim worse and think less efficiently of seeking shelter from predators. On top of that, up to 80% of fish turned out to be blind or parcel blind due to lenticular opacity.

Via a series of experiments the researcher had determined that abnormally high fluctuations of magnetic field strength cause more danger for fish than field weakening due to the shielding effect of iron walls of the pools. Velocity of fry's travel being equal to 150 centimeters per second within the space with magnetic field gradient making approximately 1.5 microT/cm, the field alteration rate may achieve 225 microT/sec. That, in turn, is fraught with generation of powerful inductive currents in the

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