Which action will decrease a radiographer's occupational exposure most during an exam?

Which action will decrease a radiographer's occupational exposure most during an exam?

• A. Increase apron thickness from 0.5 mm to 1 mm of lead equivalent.
• B. Cut the time of exposure in half.
• C. Double the distance between the radiographer and the source.
• D. Increase apron thickness from 0.5 mm to 1 mm of aluminum equivalent.

Answer: (C)

Distance has the strongest effect on reducing occupational exposure because of the inverse square law: doubling the distance from the X-ray source cuts the dose to one quarter of what it would be at the original distance. That fourfold reduction is larger than what you get from halving the exposure time (which halves the dose). Shielding helps, but its impact depends on the energy of the beam; increasing lead shielding from 0.5 mm to 1 mm reduces exposure, though typically not as dramatically as a fourfold distance increase. Aluminum shielding, while lighter, attenuates diagnostic radiation far less effectively than lead, so it provides much less protection. So, moving farther away from the source yields the greatest decrease in occupational exposure.

Distance has the strongest effect on reducing occupational exposure because of the inverse square law: doubling the distance from the X-ray source cuts the dose to one quarter of what it would be at the original distance. That fourfold reduction is larger than what you get from halving the exposure time (which halves the dose). Shielding helps, but its impact depends on the energy of the beam; increasing lead shielding from 0.5 mm to 1 mm reduces exposure, though typically not as dramatically as a fourfold distance increase. Aluminum shielding, while lighter, attenuates diagnostic radiation far less effectively than lead, so it provides much less protection. So, moving farther away from the source yields the greatest decrease in occupational exposure.