It is in our homes and even in our bodies. This is called natural or background radiation. In addition to background radiation, there is also man-made radiation. It comes from such things as medical and dental x-rays, color televisions, smoke detectors and some watches with dials that glow in the dark. Very small amounts of radiation come from nuclear power plants.
Radiation is measured in units called millirems.
A millirem is a unit of radiation dosage used to measure exposure to humans. For radiation to cause any measurable biological effect in human beings, most scientists agree that the exposure must reach about 25,000 millirems in a single, short time exposure. The NRC further required that no member of the public be exposed to more than five millirems a year from the operation of a nuclear power plant. Copyright 1990-2001 Louisiana Department of Environmental Quality. All Rights Reserved.