Radioactivity: ionising radiation

Our bodies are exposed to radioactivity from the earth and the universe on a daily basis. This radioactivity – which is also referred to as ionising radiation – is invisible, painless and colourless. Ever since the discovery of this natural phenomenon, humans have sought to understand it, transform it and put it to a variety of uses. As such, in addition to natural radioactivity, there is also man-made (or artificial) radioactivity.