Hospital/X-ray facility finishes — plaster used for radiation shielding X-ray rooms require wall finishes that attenuate ionizing radiation. Which plaster is commonly specified to improve shielding performance (often used with lead lining or high-density blocks as required)?

Introduction / Context:
Diagnostic imaging suites must control X-ray leakage through room envelopes. Besides structural provisions like lead sheets and heavy concrete/blocks, high-density plasters can be specified to add attenuation where appropriate. The correct material choice improves staff and public safety and aids compliance with radiation regulations.

Given Data / Assumptions:

• Internal wall finish inside X-ray rooms.
• Supplemental measure; not a substitute for lead where shielding calculations require it.
• Focus on plaster types used specifically for radiation attenuation.

Concept / Approach:

Barium plaster incorporates barium sulfate or similar heavy fillers to increase density and thus attenuation of X-ray photons. It is often specified with thickness verified by shielding calculations. Plaster of Paris is for general finishing/moulding. Martin’s and Keen’s cements are specialized hard plasters but not intended for radiation shielding.

Step-by-Step Solution:

Verification / Alternative check:

Radiation protection guidelines list barium plaster as an acceptable supplementary shielding material where design calculations show it is adequate, usually alongside lead sheets or dense concrete as primary barriers.

Why Other Options Are Wrong:

• Plaster of Paris is lightweight and not shielding-focused.
• Martin’s and Keen’s cements are for hard, smooth finishes but not for radiation attenuation.

Common Pitfalls:

• Assuming barium plaster alone suffices without shielding calculations; always verify required lead equivalence.

Final Answer:

Barium plaster.