TERRESTRIAL RADIATION

Background radiation is the ionizing radiation emitted from a variety of natural and artificial radiation sources. Primary contributions come from:Sources in the Earth. These include sources in our food and water, which are incorporated in our body, and in building materials and other products that incorporate those radioactive sources; Sources from space, in the form of cosmic rays; Sources in the atmosphere. One significant contribution comes from the radon gas that is released from the Earth's crust and subsequently decays into radioactive atoms that become attached to airborne dust and particulates. Another contribution arises from the radioactive atoms produced in the bombardment of atoms in the upper atmosphere by high-energy cosmic rays.
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The total infrared radiation emitted by the Earth and its atmosphere in the temperature range of approximately 200 to 300 Kelvin. Terrestrial radiation provides a major part of the potential energy changes necessary to drive the atmospheric wind system and is responsible for maintaining the surface air temperature within limits of livability.

The portion of the natural background radiation that is emitted by naturally occurring radioactive materials, such as uranium, thorium, and radon in the earth.