Most radiation damage in soft tissue happens indirectly. Which mechanism explains this indirect effect?

Giải thích

Because cells are largely water, most photons ionize water molecules and create highly reactive free radicals, which then damage DNA and other critical molecules; this is the indirect theory. A direct hit on DNA does occur but is far less common, and it does not always break both strands. Radiation injury is ionizing, not thermal, and ionization removes electrons rather than adding them.