Effective dose (EfD) incorporates which factors?

Effective dose (EfD) incorporates which factors?

• A. Exposed tissue only
• B. Radiation weighting factor and tissue weighting factor
• C. Absorbed dose and tissue mass
• D. Exposure rate and distance

Answer: (B)

Effective dose is a single risk-oriented measure that combines how energy is deposited by radiation with how different tissues respond to that energy. It uses two kinds of weighting: a radiation weighting factor to account for the biological effectiveness of the radiation type, and tissue weighting factors to reflect the varying sensitivity of different tissues to radiation risks. Concretely, you first determine the equivalent dose for each tissue by multiplying the absorbed dose in that tissue by the radiation weighting factor. Then you multiply each tissue’s equivalent dose by its tissue weighting factor and sum across all tissues. This is why the factors involved are the radiation weighting factor and the tissue weighting factor: they translate physical energy deposition into a risk-weighted, overall dose. Other options don’t fit because they omit these essential weights or bring in concepts not used in the EfD calculation. Absorbed dose is part of the calculation, but EfD relies on the weighting factors to convert it into a risk measure, not tissue mass alone. Exposure rate and distance relate to how exposure is encountered, not how EfD is defined.

Effective dose is a single risk-oriented measure that combines how energy is deposited by radiation with how different tissues respond to that energy. It uses two kinds of weighting: a radiation weighting factor to account for the biological effectiveness of the radiation type, and tissue weighting factors to reflect the varying sensitivity of different tissues to radiation risks.

Concretely, you first determine the equivalent dose for each tissue by multiplying the absorbed dose in that tissue by the radiation weighting factor. Then you multiply each tissue’s equivalent dose by its tissue weighting factor and sum across all tissues. This is why the factors involved are the radiation weighting factor and the tissue weighting factor: they translate physical energy deposition into a risk-weighted, overall dose.

Other options don’t fit because they omit these essential weights or bring in concepts not used in the EfD calculation. Absorbed dose is part of the calculation, but EfD relies on the weighting factors to convert it into a risk measure, not tissue mass alone. Exposure rate and distance relate to how exposure is encountered, not how EfD is defined.