What does the term "equivalent dose" measure?

The term "equivalent dose" refers to the biological effect of radiation on human tissue. It takes into account not only the amount of radiation energy absorbed by the tissue (which is measured as absorbed dose) but also the different effects that various types of radiation can have on living organisms. For example, alpha particles are more damaging than beta particles or gamma rays for the same amount of energy absorbed because of their higher mass and charge.

The equivalent dose calculation applies a weighting factor to the absorbed dose based on the type of radiation and its biological impact. This is expressed in sieverts (Sv), which allows for a more accurate assessment of risk for various radiation types, thereby providing a measure that incorporates both the physical and biological effects of the radiation exposure. This distinction is important in fields such as healthcare, radiation protection, and radiological safety, as it guides decision-making and safety standards when dealing with radiation exposure.