Which statement defines effective dose?

Which statement defines effective dose?

• A. Absorbed dose multiplied by the tissue's radiation weighting factor for a single tissue.
• B. The sum of absorbed doses across all tissues.
• C. Sum of equivalent doses across tissues, each weighted by tissue factors.
• D. Air changes per hour.

Answer: (C)

In radiation protection, effective dose represents a risk-weighted sum of doses absorbed by all tissues. The key idea is that not all tissues respond the same way to radiation, and the same energy deposition can pose different levels of risk depending on the tissue. So, for each tissue, you first convert the absorbed dose D_T into an equivalent dose H_T by multiplying by the radiation weighting factor w_R (which accounts for the type of radiation). Then you weight that tissue’s equivalent dose by a tissue weighting factor w_T that reflects how sensitive that tissue is to radiation. Adding these weighted equivalent doses across all tissues gives the effective dose. This single value allows comparison of overall potential risk from different exposures. Why the other possibilities don’t fit: one option would give the equivalent dose for just a single tissue, not the whole-body risk. Another would sum absorbed doses without accounting for differences in tissue sensitivity or radiation type. The last option is unrelated to radiation dose and instead describes a ventilation metric.

In radiation protection, effective dose represents a risk-weighted sum of doses absorbed by all tissues. The key idea is that not all tissues respond the same way to radiation, and the same energy deposition can pose different levels of risk depending on the tissue. So, for each tissue, you first convert the absorbed dose D_T into an equivalent dose H_T by multiplying by the radiation weighting factor w_R (which accounts for the type of radiation). Then you weight that tissue’s equivalent dose by a tissue weighting factor w_T that reflects how sensitive that tissue is to radiation. Adding these weighted equivalent doses across all tissues gives the effective dose. This single value allows comparison of overall potential risk from different exposures.

Why the other possibilities don’t fit: one option would give the equivalent dose for just a single tissue, not the whole-body risk. Another would sum absorbed doses without accounting for differences in tissue sensitivity or radiation type. The last option is unrelated to radiation dose and instead describes a ventilation metric.