Background radiations are natural radiations that are always present in the environment.
It includes cosmic radiation which comes from the sun and stars, terrestrial radiation which comes from the Earth, and internal radiation which exists in all living things.
Most of the background radiation occurs naturally from minerals and a small fraction comes from man-made elements.
Naturally occurring radioactive minerals are usually found in the ground, soil, and water and produce background radiation.
The human body also contains some of these naturally-occurring radioactive minerals.
The amount of ionizing radiation in the environment at a given area is not due to the purposeful placement of radiation sources.
Medical treatments, such as getting X-rays for X-ray photos, account for nearly all artificial background radiation.
More than half of the average annual radiation exposure of people in some countries comes from natural sources.
The natural radionuclide, radon, is one of the largest natural sources of exposure.
Radon is a kind of natural radioactive gas that gets into homes and buildings.
Uranium, thorium, and potassium are the radioactive elements that are found in rock and soil.
Thus, one of the many sources of background radiation is rock and soil.