Comparing RBE to relative penetrating power?

[Eve Litman]

Relative biological effectiveness is a factor that radiation dose is multiplied by to account for differences in biological damage by varying types of radiation. RBE is higher for alpha particles than any other, yet the relative penetrating power of alpha radiation is the smallest of the four types of radiation, and alpha radiation is not the most harmful to humans. Why doesn't RBE correspond to how harmful a type of radiation is?

 

[ZapperZ]

Relative biological effectiveness is a factor that radiation dose is multiplied by to account for differences in biological damage by varying types of radiation. RBE is higher for alpha particles than any other, yet the relative penetrating power of alpha radiation is the smallest of the four types of radiation, and alpha radiation is not the most harmful to humans. Why doesn't RBE correspond to how harmful a type of radiation is?

Because it doesn't know how or where the radiation comes from. Your scenario always assumes that it is coming from outside the body, and thus, have to penetrate through the skin. The RBE doesn't account for that. All it does is for 1 kg of tissue, how much damage does each of those cause when compared to the damage done by x-ray.

Zz.

 

[Eve Litman]

Thank you!