What is the definition of "background radiation"?

Background radiation refers to the natural radiation present in the environment that originates from cosmic sources, terrestrial materials, and even from certain foods. This type of radiation is constantly around us and is part of the normal radiation exposure that all living beings experience. It comes from sources such as radon gas released from the ground, cosmic rays from space, and the natural radioactive decay of elements like uranium and thorium found in the earth's crust.

Understanding the concept of background radiation is important for distinguishing it from radiation from artificial sources, which is specifically produced by human activities and technologies, such as medical imaging or nuclear power generation. Furthermore, background radiation does not exclusively originate from nuclear power plants or any one specific source; rather, it is a cumulative result of various natural processes, making it a fundamental component of the environment.

This distinction helps clarify that while all forms of radiation can have effects on health, background radiation is typically at a low level and is not considered harmful in the amounts that people are usually exposed to.