Which factor is used to calculate dose equivalent?

Dose equivalent is a measure that accounts for the biological effect of different types of radiation on human tissue. The calculation of dose equivalent involves the use of the quality factor, which is a dimensionless number that reflects the type of radiation and its potential to cause biological damage. Different types of radiation, such as alpha particles and beta particles, have different biological effects even at the same energy deposition, hence the need for the quality factor.

For instance, alpha particles are generally more damaging than beta particles for the same amount of energy absorbed, due to their higher mass and charge, so they have a higher quality factor. This allows for a more accurate assessment of the potential harm from exposure to various types of radiation, making the quality factor a crucial component in determining the dose equivalent.

While energy deposition, mass of absorbing tissue, and radiation level in air are all relevant factors in radiation exposure and dosimetry, they do not directly account for the differing biological effects of radiation types in the same way that the quality factor does. Therefore, the quality factor is the key factor used in the calculation of dose equivalent.