What is Radiation?
Radiation is energy travelling through space.
Where does radiation come from?
“Life on earth has developed with an ever present background of radiation. It is not something new, invented by the wit of man: radiation has always been there” – Eric J Hall, Professor of Radiology, College of Physicians and Surgeons, Columbia University, New York, in his book “Radiation and Life”.
Background radiation is that which is naturally and inevitably present in our environment. Levels of this can vary greatly. People living in granite areas or on mineralised sands receive more terrestrial radiation than others, while people living or working at high altitudes receive more cosmic radiation. A lot of our natural exposure is due to radon, a gas which seeps from the Earth’s crust and is present in the air we breathe.
Sunlight is a type of radiation – we get burnt if we are exposed to it for too long.
An important contributor to the heat within the Earth’s mantle is attributed to radioactive decay (from primarily potassium, uranium and thorium). It is the decay of these isotopes which in creating radiation also create masses of heat, which in turn drives tectonic plate movement, shaping all forms of life.
Radiation is also created by man for various reasons:
Of these, the majority of exposure to life in general comes from medical sources. To a MUCH lesser degree, nuclear power and weapons testing.