Biological effects of HF EM fields/radiation

[sandy.bridge]

Hey all,

Random question, but is there anyone in the microwave/radio frequency industry that also wonders the biological effects of constantly being exposed to it? From what I have been told, the effects are not scientifically sound, and as such, the majority of people I have met treat that conclusion as there are no effects at all. Am I odd/weird for this to cross my mind, or are there others? No one around me seems to care/acknowledge the fact that it really is Russian roulette because there are no answers. Are there people out there looking out for us and studying the effects? Or are my inherent worries for a good reason? Currently we work in the frequency range of [15, 30]Ghz, but everything is jumping to 60GHz.

Thanks in advance. Felt the need to vent I suppose.

 

[Baluncore]

Many people have tried to find such effects. But scientifically reproducible results have proved elusive.

Being an AC field, and having very low field strengths, makes it highly unlikely that any chemical change might be induced.

EM fields at microwave frequencies, (measured in GHz), are strongly attenuated and so do not penetrate wet biological samples more than a couple of millimetres. They really do not enter deep into a body.
Typical depths are 1.6mm @ 20GHz, 1.3mm @ 30GHz, 1.12mm @ 40GHz, 0.92mm @60GHz.
For an equation see; http://en.wikipedia.org/wiki/Skin_effect#Formula

The thermal heating effects of high power transmitters and microwave ovens are very well known and avoided.
The fear of microwave communication signals is more harmful than is the radiation itself.
Any low power EM radiation effects are swamped by tobacco smoking and alcohol consumption.
UV radiation from sunlight is far more dangerous than are radio communication transmissions.

 

[meBigGuy]

There is all sorts of anecdotal evidence that people can be "RF or Powerline sensitive" in as many ways as you can imagine. I have a friend that worked for years near high energy microwaves that swears he and his coworkers only had daughters.

Another friend that had a tumor where his cellphone was pocketed (way back when cellphones were first "pocketable" and high power)

There are many stories, but no reproducible scientific results. What I have read have been meta studies that made really loose "correlation equals causation" assumptions.

It's hard to imagine that there are NO effects. I do think the assumption that you can only get ill effects if the energy levels are adequate to disrupt chemical bonds is a poor one.

 

[Baluncore]

The frequency, wavelength and energy levels of photons at microwave frequencies are …
1 GHz = 300 mm = 4.13 m eV
10 GHz = 30 mm = 41.3 m eV
100 GHz = 3 mm = 413. μ eV
These are a long way below the noise levels existing in normal body chemistry.

I do think the assumption that you can only get ill effects if the energy levels are adequate to disrupt chemical bonds is a poor one.

Can you suggest some hypothetical ill effect that could be caused without a chemical change?

 

[meBigGuy]

Simple change of temperature can cause modification of reactions. All sorts of things can change the environment in which these delicate interactions occur.

Don't get me wrong. I don't subscribe to the EMF hysteria. But I don't dismiss the fact that the human body contains a complex and sensitive chemical based messaging system. Watch Bruce Lipton videos. He goes overboard (delusional?), but the fundamental biological chemical processes he describes are really interesting and really sensitive.

 

[Baluncore]

Simple change of temperature can cause modification of reactions. All sorts of things can change the environment in which these delicate interactions occur.

Cooking things does cause chemical reactions. But I find it very hard to believe that a 5 watt data link at a few 10s of GHz could cause that much cooking / heating. Taking a hot bath, or a holiday in the tropics would have a greater effect.

I would really like to know of some “magic” frequency, that causes a specific chemical reaction to take place in the body, through an E=h.u quantum effect rather than simple heating.

Has anyone ever reported an effect on the body from the presence of a permanent magnet in or near a human body?

 

[the_emi_guy]

Hey all,

...Currently we work in the frequency range of [15, 30]Ghz, but everything is jumping to 60GHz.

Thanks in advance. Felt the need to vent I suppose.

Maybe define for us what you mean by "work in". There may be some real precautions you need to know about.

There is a big difference between working with 60GHz guided by stripline, semi rigid etc. on a lab bench vs. spending all day in an anechoic chamber exposed to 10V/m coming out of a horn.

 

[Baluncore]

Has anyone ever reported that the permeability of a specific type of membrane, could be modulated for a specific chemical species, by a specific frequency of EM radiation ?