Which description characterizes effects that have a threshold dose below which the effect does not occur and above which severity increases?

Which description characterizes effects that have a threshold dose below which the effect does not occur and above which severity increases?

• A. Tissue effects/deterministic
• B. Stochastic
• C. Both Tissue effects/deterministic and Stochastic
• D. None of the above

Answer: (A)

Deterministic (tissue) effects have a threshold dose: nothing happens below that level, but once you pass the threshold the effect appears and its severity grows with the dose. This is because there’s a minimum amount of damage needed to produce the tissue response, and more dose causes more cells to be damaged, leading to greater severity. In contrast, stochastic effects (like cancer) have no true threshold—the probability of occurrence rises with dose, but the severity of the effect isn’t linked to how much dose beyond that point. So the description fits tissue effects/deterministic.

Deterministic (tissue) effects have a threshold dose: nothing happens below that level, but once you pass the threshold the effect appears and its severity grows with the dose. This is because there’s a minimum amount of damage needed to produce the tissue response, and more dose causes more cells to be damaged, leading to greater severity. In contrast, stochastic effects (like cancer) have no true threshold—the probability of occurrence rises with dose, but the severity of the effect isn’t linked to how much dose beyond that point. So the description fits tissue effects/deterministic.