Which term is used to compare the effects of radiation on living systems?

The term that is used to compare the effects of radiation on living systems is relative biological effectiveness (RBE). RBE quantifies the biological effect of different types of radiation by comparing the dose of a reference radiation that produces a specific biological effect to the dose of the radiation being studied that produces the same effect. This means it takes into account not only the energy deposition of radiation but also the biological response it elicits in tissues.

Relative biological effectiveness is especially important in contexts where one type of radiation may cause different types or magnitudes of biological damage compared to another type. For example, alpha particles, which are heavily charged and have a high linear energy transfer (LET), may cause more significant biological damage than beta particles or gamma rays even if the total energy deposited is the same. By using RBE, medical professionals and researchers can better assess risks and effects associated with various radiation treatments or exposures in living organisms.