Organ Dose Limits under 10 CFR 20 are based on preventing which type of radiation effects?

• A. Stochastic
• B. Deterministic
• C. Genetic
• D. Non-Stochastic

Answer: (D)

The main idea is that organ dose limits are set to prevent deterministic (non‑stochastic) effects. Deterministic effects have a threshold dose: below this threshold nothing happens, and above it the likelihood and severity of tissue damage increase in a predictable way. By keeping exposure below these thresholds, regulatory limits aim to avoid organ reactions such as tissue damage, erythema, or cataracts.

Stochastic effects (like cancer or genetic changes) are probabilistic and don’t have a sharp threshold, so they’re addressed by generally keeping doses as low as reasonably achievable rather than by guaranteeing the absence of a reaction. But for organ dose limits, the emphasis is on preventing those threshold-based, deterministic outcomes.