What is relative biological effect?

Relative biological effectiveness (RBE) is a measure of how harmful different types of ionizing radiation are to living organisms. RBE compares the amount of biological damage caused by a particular type of radiation to the amount of damage caused by an equivalent dose of standard ionizing radiation such as X-rays or gamma rays.

RBE values vary depending on the type and energy of the radiation, as well as the organism or tissue being exposed. For example, alpha particles have a higher RBE than X-rays or gamma rays because they interact more strongly with tissue and cause more damage per unit of energy deposited. In contrast, neutrons have a lower RBE than X-rays or gamma rays, as they cause less direct ionization.

The RBE concept is important in radiation protection because it helps to determine safe exposure limits for different types of radiation. It can also be used to assess the relative effectiveness of different cancer treatments, such as proton therapy, which uses high-energy protons with a higher RBE than X-rays or gamma rays.