b. Suppose a person absorbed 50 mrad of alpha radiation. What would be the equivalent dose in millisieverts?

Verified step by step guidance

1. Understand that the problem involves converting an absorbed dose of radiation from millirads (mrad) to millisieverts (mSv).
2. Recall that the equivalent dose in sieverts (Sv) is calculated by multiplying the absorbed dose in grays (Gy) by a radiation weighting factor (WR).
3. Note that 1 rad = 0.01 Gy, so convert the absorbed dose from mrad to Gy by multiplying by 0.01 and then dividing by 1000 to convert to Gy.
4. Recognize that for alpha particles, the radiation weighting factor (WR) is 20.
5. Calculate the equivalent dose in mSv by multiplying the absorbed dose in Gy by the radiation weighting factor (WR) and then converting the result to mSv by multiplying by 1000.

Key Concepts

Alpha Radiation

Alpha radiation consists of helium nuclei emitted from radioactive materials. It is relatively heavy and positively charged, which means it has low penetration power and can be stopped by a sheet of paper or human skin. However, if alpha particles are ingested or inhaled, they can cause significant biological damage due to their high mass and energy.

Dose Measurement Units

Radiation dose is measured in units such as rad, gray, and sievert. The rad is a unit of absorbed dose, while the sievert (Sv) is a unit that accounts for the biological effects of radiation. Millisieverts (mSv) are a subunit of sieverts, where 1 Sv equals 1,000 mSv, allowing for easier expression of doses typically encountered in medical and environmental contexts.

Radiation Weighting Factor

The radiation weighting factor (WR) is used to convert absorbed dose (in grays or rads) to equivalent dose (in sieverts or rems) by accounting for the biological effectiveness of different types of radiation. For alpha particles, the WR is typically set at 20, meaning that 1 rad of alpha radiation is equivalent to 20 rems, or 0.2 Sv, which is crucial for calculating the equivalent dose in millisieverts.