Which measurement unit is commonly used to express the biological effectiveness of ionizing radiation?

The unit commonly used to express the biological effectiveness of ionizing radiation is the sievert. The sievert measures the biological effect of radiation in terms of the potential damage it can cause to human tissue. This unit takes into account not only the amount of energy deposited in the tissue (like the gray does) but also the type of radiation and its relative biological effectiveness.

This distinction is crucial, as different types of radiation (such as alpha particles, beta particles, or gamma rays) have varying impacts on living cells, even if they deposit the same amount of energy. By utilizing the sievert, professionals in radiation protection can more effectively assess and communicate the risk associated with different exposure scenarios, ensuring better safety protocols in environments where people may be exposed to ionizing radiation.