Initiating Mechanisms of Radiological Effects
1.Direct Action
The gross biological effects resulting from over exposure to radiation
are the sequel of a long and complex series of events that are initiated
by ionization or excitation of relatively few molecules in organism.
Direct effects of radiation, ionization, and excitation are nonspecific
and may occur anywhere in the body.
2.Indirect Action
Radiation is thus seen to produce biological effects by two mechanisms,
namely, directly by dissociating molecules following their excitation and
ionization and indirectly by the production of free radicals and hydrogen
peroxide in the water of the body fluids.