Late effects of radiation exposure are best described as which of the following?

• A. Predictable
• B. Unpredictable
• C. Stochastic
• D. Deterministic

Answer: (B)

Late effects appear long after exposure and vary greatly from person to person, so you can’t know in advance who will develop them or when they will appear. That lack of certainty for an individual is why they’re best described as unpredictable. While the overall risk of such effects, like cancer, increases with dose, this doesn’t translate into a predictable outcome for a specific person. The other terms don’t fit as well: predictable would imply certainty, deterministic would imply a fixed threshold and a definite outcome for exposed individuals, and while there is a probabilistic element to risk (stochastic), the everyday description that captures the individual’s lack of predictability is unpredictable.