Which are the appropriate units of measurement for the biological effects of radiation on a human being?

Which are the appropriate units of measurement for the biological effects of radiation on a human being?

• A. rads and grays
• B. rems and sieverts
• C. roentgens
• D. curies and becquerels

Answer: (B)

The key idea is that the biological impact of radiation is described by dose equivalent, not just energy deposited. Dose equivalent combines how much energy is deposited (dose) with how damaging that energy is for the specific type of radiation and the tissues involved. That’s why the units rem and sievert are used—they express this biological effect. Sieverts are the SI unit for dose equivalent, and rems are the older unit that serves the same purpose. They account for radiation quality and tissue sensitivity, so they give a better sense of potential harm to a person than simply measuring energy deposited. Other options measure things that aren’t direct indicators of biological effect. A gray measures absorbed energy per kilogram, which tells you about energy deposition but not how biologically damaging it is. A roentgen measures exposure in air, not dose to the body. Curies and becquerels measure radioactivity or how much material is present, not the dose or its biological impact. So, rems and sieverts are the appropriate units because they reflect the actual biological risk from the radiation.

The key idea is that the biological impact of radiation is described by dose equivalent, not just energy deposited. Dose equivalent combines how much energy is deposited (dose) with how damaging that energy is for the specific type of radiation and the tissues involved. That’s why the units rem and sievert are used—they express this biological effect.

Sieverts are the SI unit for dose equivalent, and rems are the older unit that serves the same purpose. They account for radiation quality and tissue sensitivity, so they give a better sense of potential harm to a person than simply measuring energy deposited.

Other options measure things that aren’t direct indicators of biological effect. A gray measures absorbed energy per kilogram, which tells you about energy deposition but not how biologically damaging it is. A roentgen measures exposure in air, not dose to the body. Curies and becquerels measure radioactivity or how much material is present, not the dose or its biological impact.

So, rems and sieverts are the appropriate units because they reflect the actual biological risk from the radiation.