As LET increases, how does it affect biological damage from radiation?

When Linear Energy Transfer (LET) increases, the biological damage from radiation also increases. LET refers to the amount of energy that a radiation particle transfers to the surrounding material per unit distance traveled. High LET radiation, such as alpha particles or fragments from nuclear reactions, deposits more energy in a given volume compared to low LET radiation, such as gamma rays or X-rays.

This increase in energy deposition results in a higher probability of causing ionization and damage at the molecular and cellular levels. High LET radiation can create double-strand breaks in DNA, which are particularly challenging for the cell to repair. Unlike low LET radiation, which spreads its energy over a larger area and may cause single-strand breaks that can be repaired more easily, high LET radiation concentrates its energy in a smaller region, leading to increased biological effects.

As a result, tissues that experience higher doses of high LET radiation can suffer more significant damage, often leading to increased cell death, mutations, and potentially carcinogenesis. Thus, the relationship between increasing LET and biological damage is direct: as LET rises, so does the extent of biological damage from radiation exposure.