Hazards of Earth'sMagnetic Field?

Question

A child sleeping near a domestic an a.c power line is exposed to a magnetic field which may be dangerous. The Earths magnetic field strength is about the same as that of the power line but does not pose a hazard . Why

Answer 1

The earths magnetic field is static, but an Alternating Current source will fluctuate, reversing its North-south polarity 60 times a second.

The affects of fluctuating magnetic fields are very different from the effects of a fixed field.

"A strong changing magnetic field can induce electrical currents in conductive tissue, such as the brain. Since the magnetic field will penetrate tissue, it can be generated outside of the head to induce currents within, hence Transcranial magnetic stimulation. These currents will depolarize neurons in a selected part of the brain, leading to changes in the patterns of neural activation."

See the link below for more details:

Answer 2

The earth's magnetic field is always present. There is no switch that lets you turn it off. So there is really no way to measure the effect of this field on humans. And even if there was some way, and we found that the earths magnetic field was killing humans by the millions, there is little we can do about it.

Finally realize that human evolution has always occured with some background magnetic field, so it would be safe to assume that are bodies have evolved to tolerate and survive in a magnetic field.

Answer 3

While the earth's magnetic field at a given location is practically steady and unidirectional, the magnetic field of an a.c. power line fluctuates and changes direction with the same frequency as the line current. This also means that the effective magnetic field of the power line is its root mean square (r.m.s.) value, which is about 1.4 times as large as the earth's magnetic field. This is why it is more harmful than the latter.

Answer 4

The earth's magnetic field is a lot weaker than that of a million volt transmison line..
In a transimison line there is a changing field . The fact that the field is changing it may affect humans. Studies have been made;however not on a long therm basis.

Answer 5

The ac hazard might be ,if that were true aren't u subjected to much more dangerous radiation like TV stations etc ,the variables are far to great to accept your first assumption. There is a lot of research that needs to be done,u must stop jumping to an assumption that is not known..