What radiation weighting factor Wr is assigned to radiation with a larger relative biological effectiveness (RBE)?

What radiation weighting factor Wr is assigned to radiation with a larger relative biological effectiveness (RBE)?

• A. High Wr
• B. Low Wr
• C. Wr is not influenced by RBE
• D. Wr is always 1

Answer: (A)

Wr tracks how damaging a type of radiation is per unit absorbed dose. When a radiation has a larger relative biological effectiveness (RBE), it causes more biological harm for the same dose, especially high-LET radiations that create dense, complex DNA damage. To reflect that greater harm in dose calculations, that radiation type is assigned a higher Wr. For example, alpha particles have a high Wr (around 20) because of their greater biological damage, while photons and electrons have Wr of 1. Neutrons vary with energy but can also have Wr values greater than 1. So radiation with larger RBE gets a higher Wr.

Wr tracks how damaging a type of radiation is per unit absorbed dose. When a radiation has a larger relative biological effectiveness (RBE), it causes more biological harm for the same dose, especially high-LET radiations that create dense, complex DNA damage. To reflect that greater harm in dose calculations, that radiation type is assigned a higher Wr. For example, alpha particles have a high Wr (around 20) because of their greater biological damage, while photons and electrons have Wr of 1. Neutrons vary with energy but can also have Wr values greater than 1. So radiation with larger RBE gets a higher Wr.