Which statement describes the purpose of tissue weighting factors?

• A. To adjust for dose rate variations.
• B. To reflect the relative risk of stochastic effects in different tissues when calculating effective dose.
• C. To convert dose to energy.
• D. To account for deterministic thresholds.

Answer: (B)

Tissue weighting factors express how much a given tissue’s irradiation contributes to the overall risk of stochastic effects, like cancer, when estimating effective dose. They are used in the formula for effective dose by weighting each tissue’s absorbed dose with its w_T and summing across all tissues. This reflects that different tissues have different radiosensitivities and cancer risks, so the same dose to one tissue doesn’t carry the same risk as the same dose to another. The resulting effective dose is a single risk-weighted measure that allows comparison of different exposure scenarios and guides protection standards. They are not about adjusting dose rate, converting dose to energy, or addressing deterministic thresholds.