Is Microwave Dangerous?
The microwave shall not be mixed up with x-ray
radiation or radioactivity, which is also called ionizing radiation. Microwave is an
electromagnetic wave, generated in a high frequency generator, which is tuned at a fixed
oscillating frequency. The microwave is only present as long the generator is being
operated.
Naturally radioactivity can not be switched off. The x-rays pass through the human body
due to its very high energetically velocity and they can damage the cells or the genes. At
radiologists the switched x-ray energy (also called roentgen) is carefully chosen to
obtain a picture of body parts at minimized risk of damage.
A too high energy density of microwave can harm a human body up to irreparable damages, if
he is exposed to the microwave due to an accident or handling mistake. The eyes are most
endangered. Local heat up due to the exposed microwave energy would lead to blindness.
Different to the higher frequency infrared or heat waves, which the skin of human body is
sensing as heat, the microwave is intruding a few centimeter into the body, without being
immediately sensed by the skin as heat. The energy level of the intruding microwave is
exponentially decreasing against zero by absorption (conversion into heat). Until this in
the body generated heat is reaching by conduction the heat sensitive cells of the skin, a
potential damage can already being done to the body, if the energy level of the microwave
is too high. A small amount of microwave energy is being use at doctors offices in
diathermy application.
The limit for the maximal permitted energy density of microwave to which a human body can
be exposed without any detectable harm, is set after many tests at 5 mW/cm2.
Per definition the maximal microwave leakage energy of a microwave generator shall not be
greater than the 5 mW/cm2 at a distance of 5 cm from any possible radiating
location at the surface of a microwave generator. Because non focused microwave behaves in
its expansion similar to the light from a light bulb, the energy density is decreasing at
a level, which is reversed proportional to the square of the distance from the source.
To
read the PDF-files get yourself the Acrobat Reader from Adope.