Ask A Scientist© General Science Archive

name         emily
status       student
age          14

Question -   How do micro waves effect humans?
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Hello,

Electromagnetic radiation in the 1 mm to 1 m wavelength range (300 MHz to 
300 Ghz) is referred to as microwave radiation, and is part of what is 
known as radiofrequency (RF) radiation. The latter covers the 0.5 MHz to 
300 GHz range and is considered in the context of adverse biological effects.
RF radiation is  nonionizing radiation. This means that, in general, it 
does not have sufficient energy to kick an electron off an atom thus 
producing charged particle in a body and cause biological damage.
The only proven harmful effect from exposure to microwave (or RF) radiation 
is thermal.  RF radiation can enter deep into the body and heat human 
organs. Thus, the depth of penetration and the level absorption of 
radiation in the the body are relevant.

- Above 10 GHz (3 cm wavelength or less) heating occurs mainly in the outer 
skin surface. - From 3 GHz to 10 GHz (10 cm to 3 cm) the penetration is 
deeper and heating higher.
- From 150 MHz to about 1 GHz (200 cm to 25 cm wavelength), penetration is 
even deeper and because of high absorption, deep body heating can occur.

Any part of the body that cannot dissipate heat efficiently or is heat 
sensitive may be damaged by microwave radiation of sufficient power.   The 
lens of the eye and testes are respective examples.

Are there non-thermal ADVERSE effects of microwave radiation in humans?  We 
know that there ARE non-thermal effect: microwaves can cause hearing 
sensation, can affect behavior (in animal studies), etc.  Are these effects 
adverse and reversible? Research is still continuing in this area as well 
as in the area of RF radiation effects on immune and central nervous 
system.  Much more work is needed and maybe you can get a degree in science 
and do some research in this area.

Have said all this, it is my personal view that man-made effects (i.e., 
those that have not been a part of our natural history) have to be treated 
with caution, and lack of evidence for adverse effects is NOT the same 
thing as proof of safety.
Good Luck.
AK

Dr. Ali Khounsary
Advanced Photon Source
Argonne National Laboratory
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Since microwaves are a form of energy, they can affect humans, just like
the sun or other energy sources can.  Our skin does not like to be
bombarded with energy sources.  What can you do?  Make sure that the
door seal is kept clean and not torn.  Standing near one leaking
microwaves is not beneficial, and we could get burnt.  The skin will
redden like sunburn or get a worse burn depending on our exposure.  Used
correctly, the energy from microwaves are helpful to cut cooking times.

Van Hoeck
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