According to NCRP standards, what is the annual maximal permissible dose for non-occupationally exposed adult patients?

• A. 0.1 rem (1 mSv) per year
• B. 5 rem (50 mSv) per year
• C. 50 rem (500 mSv) per year
• D. 1 rem (10 mSv) per year

Answer: (A)

The main idea is that NCRP sets a dose limit to protect non-occupational individuals, including patients. For the general public, the annual permissible effective dose is 1 mSv (which is the same as 0.1 rem). So the correct choice corresponds to 0.1 rem per year (1 mSv per year). The other numbers are much higher and reflect occupational exposure limits (for radiation workers) or other non-applicable values. For reference, 1 rem equals 10 mSv, so the option of 1 rem per year would be 10 mSv, still above the public limit. In dental imaging, this limit guides the principle of keeping patient exposure as low as reasonably achievable while ensuring diagnostic quality.