Radiation workers should try to keep their occupational dose to a minimum. Which adjustment would decrease the absorbed dose to a radiation worker?

Radiation workers should try to keep their occupational dose to a minimum. Which adjustment would decrease the absorbed dose to a radiation worker?

• A. Decrease distance from the source
• B. Increase distance from the source
• C. Distance does not affect the absorbed dose
• D. Increase exposure time

Answer: (B)

Radiation dose falls off rapidly with distance from the source due to the inverse square law. As you move farther away, the intensity of radiation you’re exposed to decreases with the square of the distance. This means that increasing distance from the source reduces the absorbed dose—doubling the distance cuts the dose to about a quarter, tripling it reduces it to about one ninth, and so on. So the adjustment that lowers the absorbed dose is to increase the distance from the source. Decreasing distance would raise the dose, saying distance doesn’t affect dose is incorrect, and increasing exposure time would increase the dose rather than decrease it.

Radiation dose falls off rapidly with distance from the source due to the inverse square law. As you move farther away, the intensity of radiation you’re exposed to decreases with the square of the distance. This means that increasing distance from the source reduces the absorbed dose—doubling the distance cuts the dose to about a quarter, tripling it reduces it to about one ninth, and so on.

So the adjustment that lowers the absorbed dose is to increase the distance from the source. Decreasing distance would raise the dose, saying distance doesn’t affect dose is incorrect, and increasing exposure time would increase the dose rather than decrease it.