Radiation protection, sometimes known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". The IAEA also states "The accepted understanding of the term radiation protection is restricted to protection of people. Suggestions to extend the definition to include the protection of non-human species or the protection of the environment are controversial". Exposure can be from a radiation source external to the human body or due to an intake of radioactive material into the body.
Ionizing radiation is widely used in industry and medicine, and can present a significant health hazard by causing microscopic damage to living tissue. This can result in skin burns and radiation sickness at high exposures, known as "tissue" or "deterministic" effects (conventionally indicated by the gray), and statistically elevated risks of cancer at low exposures, known as "stochastic effects" (conventionally measured by the sievert ).
Fundamental to radiation protection is the reduction of expected dose and the measurement of human dose uptake. For radiation protection and dosimetry assessment the International Committee on Radiation Protection (ICRP) and International Commission on Radiation Units and Measurements (ICRU) have published recommendations and data which is used to calculate the biological effects on the human body, and thereby advise dose uptake limits. Supporting this is a necessary range of radiation protection instruments to indicate radiation hazards, and dosimeters to measure dose; assisted by preventative techniques such as radiation shielding.