How is lead used in radiation protection?

Lead is used in radiation protection primarily due to its effectiveness as a shielding material. It possesses a high atomic number and density, which makes it particularly efficient at absorbing and attenuating various types of radiation, including gamma rays and X-rays. The dense nature of lead allows it to block a significant amount of radiation, reducing exposure to individuals working in environments where radiation is present.

In medical and industrial settings, lead is commonly utilized in the form of lead aprons, barriers, and shielding around radiation sources to protect personnel and patients from excess radiation exposure. This reliable capacity of lead to diminish radiation intensity makes it an essential material in various applications aimed at ensuring safety in the presence of radiation.

The other options don't fulfill the role of lead in radiation protection: it is not a chemical agent for treatments, it is not used as a cleaning agent for surfaces contaminated with radioactive materials, and it does not function as a marker for radiation levels. Instead, lead's primary and critical role lies in its ability to effectively shield against harmful radiation.