Which statement about deterministic effects is true?

Which statement about deterministic effects is true?

• A. Deterministic effects require a threshold dose
• B. Deterministic effects do not require a threshold dose
• C. Deterministic effects can manifest in the long term
• D. Deterministic effects usually manifest in the short term

Answer: (A)

Deterministic effects have a definite threshold dose. Below this dose no adverse effect is observed, and once that threshold is exceeded, the likelihood and severity of the effect increase as the dose goes up. This threshold distinguishes deterministic effects from stochastic ones, where there is no sharp dose cutoff and the probability of an effect (not its severity) rises with dose. While some deterministic effects can appear relatively soon after exposure at higher doses, the key point is the existence of a threshold dose that must be surpassed for the effect to occur.

Deterministic effects have a definite threshold dose. Below this dose no adverse effect is observed, and once that threshold is exceeded, the likelihood and severity of the effect increase as the dose goes up. This threshold distinguishes deterministic effects from stochastic ones, where there is no sharp dose cutoff and the probability of an effect (not its severity) rises with dose. While some deterministic effects can appear relatively soon after exposure at higher doses, the key point is the existence of a threshold dose that must be surpassed for the effect to occur.