ABSTRACT
This chapter discusses ionising radiation, its common sources and its quantification, health effects, measurement and controls. It also discusses non-ionising radiation, which includes ultraviolet, visible, infrared, radiofrequency and extremely low-frequency radiation and static fields. Radiation is ionising when it has sufficient energy to remove an electron from an atom of a molecule. X-rays and gamma rays are electromagnetic radiation and can be thought of as photons. Neutron radiation, another form of particulate radiation, is typically used in specialist applications such as physics research, neutron imaging and environmental monitoring. The most common industrial application is moisture-density gauges. The International System of Radiological Protection has been developed by the International Commission on Radiological Protection, which publishes dose limits and many other ionising-radiation safety publications. A human-made source of ionising radiation can be generated by either concentrating naturally occurring radioisotopes or by using special apparatus such as an x-ray tube or a cyclotron.
