Background Radiation

Background radiation is a measure of the level of ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources. Background radiation originates from a variety of sources, both natural and artificial. These include both cosmic radiation and environmental radioactivity from naturally occurring radioactive materials, as well as man-made medical X-rays, fallout from nuclear weapons testing and nuclear accidents.

Background radiation Category
Background radiation equivalent time (BRET).
Banana equivalent dose - Banana equivalent dose is an informal unit of measurement of ionizing radiation exposure, intended as a general educational example to compare a dose of radioactivity to the dose one is exposed to by eating one average-sized banana.
Environmental radioactivity - Environmental radioactivity is produced by radioactive materials in the human environment.
Flight-time equivalent dose - Flight-time equivalent dose is an informal unit of measurement of ionizing radiation exposure. Expressed in units of flight-time, one unit of flight-time is approximately equivalent to the radiological dose received during the same unit of time spent in an airliner at cruising altitude.
Noise (electronics) - In electronics, noise is an unwanted disturbance in an electrical signal. Noise generated by electronic devices varies greatly as it is produced by several different effects. In particular, noise is inherent in physics and central to thermodynamics.
Low-background steel - Low-background steel, also known as pre-war steel, is any steel produced prior to the detonation of the first nuclear bombs in the 1940s and 1950s.
Cosmic rays
Radioactivity