BACKGROUND RADIATION

If you put a Geiger counter (radiation detector) out in the lab well away from any radioactive sources it will still read something. You will probably get between twenty and thirty counts per minute. This is known as BACKGROUND RADIATION and this radiation is around us all the time.

Background radiation comes from:
(a) deep space - cosmic rays
(b) the Sun
(c) radioactive rocks such as granite
(d) radioactive material in our own bodies
(e) radon gas from the ground
(f) the nuclear industry - fallout from nuclear tests and medical uses