Which weighting factors are used to determine the Sievert?

Which weighting factors are used to determine the Sievert?

• A. Wt
• B. Wr
• C. Wt and Wr
• D. None

Answer: (C)

The Sievert reflects risk by combining two kinds of weighting: one for the type and energy of radiation, and one for the sensitivity of each tissue. The dose the body receives in a specific tissue is first adjusted for radiation type with Wr, giving the equivalent dose H_T = Wr × D_T. Then these tissue-specific results are combined with tissue weighting factors Wt to account for how sensitive each tissue is to radiation, giving the effective dose E = Σ_T Wt × H_T. In short, determining the Sievert requires both Wr and Wt, because it merges the biological effectiveness of the radiation with the varying importance of different tissues. Using only one weighting would miss either how harmful the radiation is (if you used only Wr) or how damaging different tissues are (if you used only Wt). The option that includes both factors is the best answer.

The Sievert reflects risk by combining two kinds of weighting: one for the type and energy of radiation, and one for the sensitivity of each tissue. The dose the body receives in a specific tissue is first adjusted for radiation type with Wr, giving the equivalent dose H_T = Wr × D_T. Then these tissue-specific results are combined with tissue weighting factors Wt to account for how sensitive each tissue is to radiation, giving the effective dose E = Σ_T Wt × H_T. In short, determining the Sievert requires both Wr and Wt, because it merges the biological effectiveness of the radiation with the varying importance of different tissues. Using only one weighting would miss either how harmful the radiation is (if you used only Wr) or how damaging different tissues are (if you used only Wt). The option that includes both factors is the best answer.