Which term describes a dose-response relationship where there is no safe level, and any exposure carries risk?

• A. Deterministic effects
• B. Acute effects
• C. Stochastic effects
• D. Chronic effects

Answer: (C)

Stochastic effects describe a dose-response relationship with no safe exposure level. In this view, any amount of radiation carries some risk, and the chance that an effect like cancer or genetic mutation occurs increases as the dose rises. The severity of the effect, if it occurs, isn’t tied to how large the dose was—the risk is about probability, not intensity.

This is different from deterministic effects, which have a threshold: below a certain dose nothing happens, and above that threshold, both the likelihood and the severity of effects (like skin burns or cataracts) rise with dose. Examples of stochastic effects include cancer and heritable genetic changes, where the risk accumulates with exposure but the outcome’s seriousness isn’t dose-dependent.