Observed radiation effects may be broadly classified into
two categories.
1.Stochastic effects
= Effects that occur randomly, such as cancer
2.Deterministic effects
= Non stochastic effects
Most biological effects fall into the category of deterministic effects.
“the size of the dose determines the poison” (Paracelsus)
2.1 A certain minimum dose must be exceeded before the particular
effect is observed.
2.2 The magnitude of the effect increases with the size of the dose.
2.3 There is a clear, unambiguous causal relationship between exposure
to the noxious agent and the observed effect.