Which factor differentiates effective dose from equivalent dose?

• A. Radiation weighting factor
• B. Absorbed dose
• C. Tissue weighting factor
• D. Dose rate

Answer: (C)

Different organs respond differently to radiation, so the measurement that links dose to overall risk must account for that variation. The equivalent dose adjusts the absorbed dose for the type of radiation, giving a tissue-specific dose that reflects how destructive that radiation is to biological tissue. The effective dose goes further by weighting each tissue’s equivalent dose with a tissue weighting factor that represents how sensitive that tissue is to radiation, then summing across all tissues. This tissue weighting factor is what turns a per-tissue, radiation-type-adjusted value into a single whole-body risk estimate. Dose rate and absorbed dose aren’t what create that distinction; they’re separate concepts. So the differentiating factor is the tissue weighting factor.