ABSTRACT
A number of acute and long-term effects of radiation on animal and human species have been related to the physical energy absorbed from various types of ionizing radiation. However, the relative effectiveness of each type of radiation per unit energy absorbed in biological tissue has been found to vary not only with the type of radiation and its quantum energy, but also with the rate at which the energy is delivered, the kind of tissue, age and species of animal, the biological effect under consideration, and other experimental and epidemiologic variables. This chapter presents a list of definitions of quantities and units that will suffice in dealing with most problems in radiation protection (health physics) and dosimetry. The most useful definitions and data are presented for use in radiation dose measurements and calculations for external sources of radiation. A short summary of available quantitative data for risk determination is also included.
