Radiation is a form of energy. Everything around us is made up of small particles called atoms. The atoms in some matter are unstable and can split to form new matter. When this happens, it gives off energy called radiation. This energy can be used to make electricity, to treat cancer, and in other helpful ways.
Radiation is all around us. It is in the air we breathe, the food we eat, and the water we drink. 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.
Federal standards drawn up and enforced by the Nuclear Regulatory Commission (NRC) require that workers at nuclear power plants receive no more than 5,000 millirems of radiation a year. 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.