Which term best describes the relationship between dose and probability of cancer or genetic effects?

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

Answer: (A)

Stochastic effects describe risks that occur by chance, with the probability of occurrence rising as dose increases. For cancer and genetic effects, higher doses mean a greater chance of DNA mutations leading to cancer or heritable changes, but the severity or specific outcome isn’t determined directly by the dose. There isn’t a clear threshold where these effects suddenly appear; even small doses carry some risk, though the likelihood is lower. In contrast, deterministic (nonstochastic) effects have a threshold and become more severe with larger doses (such as skin reddening or radiation sickness), and acute effects refer to immediate symptoms after exposure rather than long-term probabilistic outcomes.