Final answer:
Ceiling mounted lead acrylic screens and moveable shields in medical settings typically require a thickness measured in millimeters of lead equivalent (mm Pb) to protect against x-ray radiation, with common requirements ranging from 0.5 mm Pb to 2 mm Pb.
Step-by-step explanation:
The question relates to the specifications of protective barriers used in medical settings, particularly in radiology departments. Ceiling mounted lead acrylic screens and moveable shields are utilized to protect healthcare workers from x-ray radiation exposure. The thickness of protection is generally measured in millimeters of lead equivalent (mm Pb). While standards can vary depending on local regulations and the type of radiological equipment in use, a common requirement for these protective barriers is 0.5 mm Pb to 2 mm Pb. It is crucial to refer to the appropriate health and safety guidelines that apply to the specific medical facility to determine the exact requirements.