For a 25-year-old, what is the cumulative exposure limit in millisieverts (mSv)?

The correct cumulative exposure limit for a 25-year-old is indeed 50 millisieverts (mSv). The exposure limit is typically calculated based on the age of the individual and is intended to minimize the risk of harmful effects from radiation exposure over a lifetime.

For occupational exposure, regulations often state that individuals should receive an annual dose limit of 20 mSv, averaged over a period of five years, although the linear accumulation of exposure is capped at a certain age. For someone who is 25 years old, it's customary to use a cumulative limit of age in years multiplied by a factor of 1 mSv per year, which would give a total of 25 mSv if assessed solely according to age. However, standards set by organizations such as the International Commission on Radiological Protection (ICRP) often allow for a higher cumulative limit, reflecting safety margins based on epidemiological studies and risk assessments.

This cumulative exposure limit allows for considerations beyond just age, taking into account the potential for higher exposure in occupational settings where radiation is part of the job. Hence, 50 mSv is aligned with both regulatory guidance and occupational safety measures determined for individuals in radiation-related fields.