What unit is commonly used to express radiation dose equivalent?

The most appropriate unit for expressing radiation dose equivalent is the rem, which has an equivalent measurement in the sievert (Sv). The concept of dose equivalent is important in radiation protection because it accounts for the biological effects of different types of radiation. The rem is designed to provide a way to quantify the impact of radiation exposure on human health by considering the type of radiation and its potential biological harm.

The rem is used to express dose equivalent because it factors in the relative biological effectiveness (RBE) of different kinds of radiation, translating the absorbed dose (measured in grays or rads) into an equivalent amount that reflects its potential biological effect. This is particularly important since not all forms of radiation produce the same level of harm for the same energy deposited in tissue.

In contrast, grays and rads are units that measure the absorbed dose, which indicates how much energy from radiation is deposited in a given mass of tissue but does not consider the biological implications. The curie is a unit of radioactivity, indicating the rate of decay of radioactive materials but does not measure doses or their effects on biological organisms, which are essential considerations in radiological protection.