What health risk is associated with a 1000 mrem occupational dose?

• A. No significant health risk.
• B. An immediate illness.
• C. A decrease in cancer risk.
• D. An increase in the risk of contracting fatal cancer by 0.04 percent.

Answer: (D)

The main idea is that very low radiation doses affect long-term risk rather than causing immediate illness. A 1000 mrem allowance translates to about 0.01 Sv. At this level, there are no acute effects, but there is a small increase in lifetime cancer risk. Using typical risk coefficients for fatal cancer, 0.01 Sv adds roughly 0.04% to the risk, which is a tiny but real increase over a lifetime. That’s why the correct view is that there is a small rise in the risk of fatal cancer, not an immediate illness or no risk at all.