Background radiation
From Conservapedia
Background radiation is the radiation of man's natural environment originating primarily from the naturally radioactive elements of the earth and from the cosmic rays. The term may also mean radiation extraneous to an experiment.[1]
There is considerable controversy over whether background radiation is harmful, insignificant, or beneficial [2] to human beings; see radiation hormesis.
Some partisans totally neglect the effects of background radiation when estimated the amount of damage occurring as a result of accidental release of radiation (see Three Mile Island, Chernobyl).
