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Is 8.6 amperes per meter, 70 microtesla, 0.70 gauss, 695 milligauss, safe on long time exposure?

I am just worried.

ocrdu
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Paul Delaunay
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  • No. Unless you have a pacemaker or similar, the human body is very insensitive to magnetic fields, especially that low. – winny Sep 05 '22 at 20:20
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    you are asking about the safety of the Earth's magnetic field – jsotola Sep 05 '22 at 20:23
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    Earth's field varies from 25 uT to 65 uT at the surface, about 50 uT over most of Europe and North America. That's a long experiment on a lot of people, with no ill effects attributal to magnetic fields, but lots of deaths due to smoking, alcohol, car crashes, drug side effects etc. Stop worrying. – Neil_UK Sep 05 '22 at 20:29
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    try 7 Tesla RF in an MRI – Tony Stewart EE75 Sep 05 '22 at 23:13
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    If you are worried about this, I urge you to speak with a qualified psychiatrist. Worry is a common issue that can be treated. – Tony Stewart EE75 Sep 05 '22 at 23:46
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    Those are magnetic field readings, not electric field readings. – Cassie Swett Sep 06 '22 at 01:36
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    Yes (with a hint of sarcasm): everyone exposed to this field intensity, chronically, developed a fatal case of death within at most ~120yr. – Tim Williams Sep 06 '22 at 02:38
  • if it was in the RF frequency band taking a reading up on an antenna tower your eyes might be burning from the electric field, but not the magnetic field. But your metal watch band might pick up the H field. – Tony Stewart EE75 Sep 06 '22 at 02:54
  • I think N. Tesla was hoping the earth's H field was this high a current to capture free energy. But it was to no avail. – Tony Stewart EE75 Sep 06 '22 at 02:57
  • Thank you all for responding I appreciate it, feel much better. – Paul Delaunay Sep 06 '22 at 05:03

2 Answers2

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According to Wikipedia :

“The magnitude of Earth's magnetic field at its surface ranges from 25 to 65 μT (0.25 to 0.65 G)”

https://en.wikipedia.org/wiki/Earth%27s_magnetic_field

So the measurement you have is essentially only the geomagnetic field, the same one we’ve experienced since birth. As to danger from static fields, the American Conference of Governmental Industrial Hygienists (ACGIH) established occupational limits which are quite high compared to your readings:

Whole body: 2 Tesla

Medical device wearers: 500 micro Tesla

Adapted from UoT's rad safety documentation, See Table 1: https://ehs.utoronto.ca/our-services/radiation-safety/emf-safety-program/

So to finalise: you are measuring a magnetic field that is effectively the same as everyone you've ever met has lived in their entire life, and standards bodies agree that our most magnetically sensitive friends can withstand 7 times as much before becoming concerned.

Bryan
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70 microtesla, 0.70 gauss, 695 milligauss.

These values are all the same but in different units.
100 microtesla = 100 uT = 1 gauss

Do we assume this is 50 or 60Hz? if so, 70 uT is below the safety agency of 100 uT for power line frequency for the public and the occupational levels permitted are 10x this level.

This level of exposure is below risk levels for continued public environment Occupational levels permit 10x the 100 uT levels at line frequency.

I found these 2010 safety references

enter image description here

Since MRI's do not use a radioactive source but rather 64 MHz or 128 MHz brief durations of 1.5 to 3 Tesla or 1500 to 3000 Gauss are consider safe for for high contrast brain and body imaging. But the subject must be void of metals containing iron implants.

There is increasing therapeutic interest in using repetitive Functional Magnetic Stimulus rFMS with repeat sessions for healing symptoms from PTSD, anxiety, tinnitus (apparent ringing in ears), clinical depression, & weight loss. The equipment is widespread in therapeutic centers around the world. One global supplier of 2 Tesla ultra-low frequency FMS machines in Slovakia. here.

For rFMS, at an extremely high level of 2 Tesla at ultra-low frequencies (ULF) stimulates the action potential in muscles but not at RF frequencies. Unlike Electrical stimulus or ECT, it is non-invasive and applied with coils near the body and only applied by experienced health care professionals.

I have done some research in this area. You might be interested in the spectral info I computed on an old image I created below.

enter image description here

Tony Stewart EE75
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