Which factor accounts for differences in tissue sensitivity when computing the effective dose?

Which factor accounts for differences in tissue sensitivity when computing the effective dose?

• A. Radiation type (Wr)
• B. Distance from source
• C. Exposure duration
• D. Tissue weighting factor (Wt)

Answer: (D)

Understanding effective dose requires recognizing that tissues don’t all respond the same way to radiation. The measure combines how much energy is absorbed by each tissue with a tissue weighting factor that represents how sensitive that tissue is to radiation-related risks like cancer or genetic effects. In other words, the effective dose is the sum across tissues of the tissue weighting factor multiplied by the absorbed dose to that tissue. This weighting makes highly sensitive tissues contribute more to the overall risk, while less sensitive tissues contribute less. For example, sensitive tissues such as bone marrow or gonads have high weighting factors, increasing their influence on the total effective dose, whereas less sensitive tissues contribute less. The radiation type weighting factor adjusts for how different types of radiation affect biology, but it’s not about tissue sensitivity. Distance from the source and exposure duration affect the actual dose received but don’t encode tissue-specific risk. So the tissue weighting factor is the element that accounts for differences in tissue sensitivity.

Understanding effective dose requires recognizing that tissues don’t all respond the same way to radiation. The measure combines how much energy is absorbed by each tissue with a tissue weighting factor that represents how sensitive that tissue is to radiation-related risks like cancer or genetic effects. In other words, the effective dose is the sum across tissues of the tissue weighting factor multiplied by the absorbed dose to that tissue. This weighting makes highly sensitive tissues contribute more to the overall risk, while less sensitive tissues contribute less. For example, sensitive tissues such as bone marrow or gonads have high weighting factors, increasing their influence on the total effective dose, whereas less sensitive tissues contribute less. The radiation type weighting factor adjusts for how different types of radiation affect biology, but it’s not about tissue sensitivity. Distance from the source and exposure duration affect the actual dose received but don’t encode tissue-specific risk. So the tissue weighting factor is the element that accounts for differences in tissue sensitivity.