What type of material is used for radiation shielding in medical applications?

Lead and concrete are commonly used materials for radiation shielding in medical applications due to their high density and atomic number, which are effective in absorbing and attenuating radiation. Lead, in particular, is favored because it is very dense and provides superior shielding against gamma rays and X-rays, which are prevalent in medical imaging and radiation therapy. Concrete is used in larger constructions, such as hospital walls or treatment rooms, thanks to its cost-effectiveness and ability to be engineered to specific thicknesses for desired radiation protection levels.

Other materials listed, while they may have some properties for shielding or structural purposes, do not provide adequate protection from radiation. For example, plastics and rubbers can block certain low-energy radiation but are not effective against high-energy radiation like gamma rays. Similarly, glass and aluminum offer minimal shielding capabilities, and while wood and drywall are common construction materials, they do not have sufficient density to effectively shield against radiation. Thus, lead and concrete stand out as the most effective materials for ensuring safety in medical settings where radiation exposure is a factor.