Which type of radiation effect has a severity that varies with dose and has a threshold, and is also known as the deterministic effect?

• A. Stochastic Effects
• B. Latent Effects
• C. Deterministic Effects
• D. Nonstochastic Effects

Answer: (D)

Deterministic effects are dose‑dependent with a clear threshold: below that threshold, no effect is observed, but once you exceed it, the likelihood and severity of the effect rise as the dose increases. This is why they’re described as non‑stochastic—the outcome is determined by the amount of radiation. The mechanism involves tissue damage that, when repair isn’t enough to prevent injury, leads to observable effects such as skin erythema, hair loss, cataracts, or other organ dysfunction, with greater dose causing more severe or earlier onset symptoms. In contrast, stochastic effects have no practical threshold—the chance of occurrence increases with dose, but the severity of the effect is not dose‑dependent. Latent effects refer to the time delay between exposure and appearance, not to how severity scales with dose.