What is the definition of "background radiation"?

Background radiation is defined as the natural ionizing radiation that is present in the environment. This type of radiation comes from various sources, including cosmic rays from outer space, terrestrial radiation from elements in the earth, and even radiation from internal sources within the human body. It is a constant and unavoidable part of our environment, contributing to the overall radiation exposure that individuals receive throughout their lives.

Understanding background radiation is essential because it serves as a baseline against which other radiation exposures, such as those from medical procedures or man-made sources, can be measured. This distinction is important in fields like radiation safety, where assessing the extra risk posed by additional exposure is crucial for patient and personnel safety.

In contrast, the artificial radiation produced in laboratories, radiation from medical imaging devices, and additional radiation from man-made sources are not classified as background radiation because they result from human activities rather than being a natural part of the environment.