Which of the following is an example of a stochastic radiation effect?

• A. Skin erythema
• B. Cataracts
• C. Cancer
• D. Nausea

Answer: (C)

Stochastic radiation effects are probabilistic outcomes: the chance of occurrence increases with the dose, but there isn’t a fixed dose at which they suddenly appear, and the severity of the effect isn’t tied to the dose in the same way. Cancer is the classic example because higher radiation exposure raises the probability of developing cancer later in life, while the cancer’s severity isn’t determined by how much dose was received.

In contrast, the other options are deterministic tissue reactions, which have dose thresholds and where the severity grows with dose. Skin erythema appears only after a certain skin dose, cataracts are typically treated as requiring a threshold dose, and nausea occurs after substantial acute exposure.