The SI unit for dose equivalent used in occupational exposure

The SI unit for dose equivalent used in occupational exposure

• A. Rem
• B. Sievert (Sv)
• C. Gray (Gy)
• D. Becquerel

Answer: (B)

Dose equivalent expresses the biological risk of radiation exposure, not just the energy deposited. It combines the absorbed dose with a radiation quality factor that reflects how damaging different types of radiation are to tissue. The SI unit for this quantity is the sievert, so occupational exposure is reported in sieverts (or millisieverts). The rem is an older non-SI unit used in some contexts, with 1 sievert equal to 100 rem. Gray measures absorbed dose (energy per mass) but does not account for how different radiations affect biology, which is why it isn’t used for dose equivalent. Becquerel measures radioactive decay activity, also not related to dose. For example, the same absorbed dose from alpha radiation results in a much larger dose equivalent than from gamma radiation due to a higher weighting factor, illustrating why sieverts are used to assess occupational risk.

Dose equivalent expresses the biological risk of radiation exposure, not just the energy deposited. It combines the absorbed dose with a radiation quality factor that reflects how damaging different types of radiation are to tissue. The SI unit for this quantity is the sievert, so occupational exposure is reported in sieverts (or millisieverts). The rem is an older non-SI unit used in some contexts, with 1 sievert equal to 100 rem. Gray measures absorbed dose (energy per mass) but does not account for how different radiations affect biology, which is why it isn’t used for dose equivalent. Becquerel measures radioactive decay activity, also not related to dose. For example, the same absorbed dose from alpha radiation results in a much larger dose equivalent than from gamma radiation due to a higher weighting factor, illustrating why sieverts are used to assess occupational risk.