ABSTRACT
This chapter discusses radiation and examines the types of radiation emitted by Naturally Occurring Radioactive Material and relates their properties. It describes the atomic decay mechanisms that produce each form of radiation. The chapter identifies the appropriate units for measuring radiation exposure, biological dose equivalent, and radioactive material. It explores the concept of half-life as it relates to the radioactive decay and biological elimination of radioactive materials. Generally, radiation can be defined as particles or energy released by an unstable atom. Radiation in the form of a particle will have a measurable size, mass, and velocity, whereas non-particulate radiation is pure energy traveling at the speed of light. Gamma radiation is excess energy that is released from the nucleus of an atom. Photon radiation resulting from charged particles undergoing collisions or acceleration is also called x-ray radiation or bremsstrahlung radiation. Most of the scientific world measures radiation and radioactivity using the Systeme Internationale units of measurement.
