Page 135 - Radiation Safety

Stochastic Effect

Carcinogenesis

• Carcinogenesis is an example of somatic stochastic effect.

• Carcinogenesis may:

▪ Occur after low dose exposure; and

▪ The probability of malignancy increases with increase in dose.

• In man there is a latent period between initiation and expression

of effects. Latent period is about 8 years for induced leukemia

and 2-3 X longer for solid tumor (eg lung and breast cancers).

• Stochastic effect is influenced by LET and dose rate.