How dangerous is electromagnetic radiation?

1 Answer

The answer depends on what wavelength is being considered.


The term "electromagnetic radiation" refers to a continuum of wavelengths, from the very long wavelengths of radio waves and microwaves to the very short of gamma and x-rays:

In terms of what is and isn't dangerous, the answers vary depending on what wavelength we are talking about. As the graphic shows below, some wavelengths, such as radio waves, pierce us continually. It takes a very strong source of such waves at close range to cause damage (I'm aware of one instance in a military setting where a sailor was on watch every night and would sit inside the "danger zone" of the ship radar to help stay warm. One night the system was powered up to maximum and he, in effect, was cooked by the waves).

On the other side of the spectrum, x-rays and gamma waves are dangerous because of how energetic they are. They come from the upper atmosphere and the Sun and yet have the power in even small amounts to adversely affect our health.