radiobiology VI

Question 1

what are the chronic effects of radiation?

Answer 1

-deterministic effect
-stochastic effect

Question 2

what is the deterministic effect?

Answer 2

severity increases with dose; practical threshold; probability of occurrence (ie. incidence) increases with dose, but exponentially after threshold (ex: cataract, late tissue fibrosis)

Question 3

what is the stochastic effect?

Answer 3

severity independent of dose; no threshold; probability of occurrence increases with dose ex: genetic effects (cancer/somatic mutations, germ-line/heritable mutations)

Question 4

what is the deterministic and stochastic effect in human population?

Answer 4

-deterministic effects: when 1% of a population responds to a radiation dose, the dose is said to be threshold dose
-stochastic effects: when dose response relationship cannot be established due to other cancer-promoting factors such as smoking, drinking. But radiation protection is required assuming they may have some effects