Which statement describes the concept that there is no safe dose and a response occurs at any dose (linear-nonthreshold)?

Which statement describes the concept that there is no safe dose and a response occurs at any dose (linear-nonthreshold)?

• A. Nonlinear-nonthreshold
• B. Linear-threshold
• C. Linear-nonthreshold
• D. Nonlinear-threshold

Answer: (C)

This concept is about how risk from radiation grows with dose. Saying there is no safe dose and that a response occurs at any dose means that even the smallest amount of radiation carries some chance of causing an effect, and that risk increases in direct proportion to how much dose you receive. That straight-line, through-origin relationship is the linear-nonthreshold model: zero dose yields zero risk, and any incremental dose adds the same incremental risk, with no minimum level below which nothing happens. This is in contrast to models with a threshold, where nothing happens below a certain dose, or nonlinear models where risk doesn’t rise in a simple straight-line way as dose increases. So the best fit for the idea of no safe dose and a response at any dose is the linear-nonthreshold concept.

This concept is about how risk from radiation grows with dose. Saying there is no safe dose and that a response occurs at any dose means that even the smallest amount of radiation carries some chance of causing an effect, and that risk increases in direct proportion to how much dose you receive. That straight-line, through-origin relationship is the linear-nonthreshold model: zero dose yields zero risk, and any incremental dose adds the same incremental risk, with no minimum level below which nothing happens.

This is in contrast to models with a threshold, where nothing happens below a certain dose, or nonlinear models where risk doesn’t rise in a simple straight-line way as dose increases. So the best fit for the idea of no safe dose and a response at any dose is the linear-nonthreshold concept.