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Maximize shielding between the radioactive source and the person being exposed. Shielding greatly reduces the amount of radiation exposure. Shielding material employed in diagnostic radiology is usually made of lead or concrete. Lead is used in most radiation protective apparels because of its high atomic number (82) and increased attenuation that ensures the absorption of the major scattered photons. Annual inspection of the lead shields should be conducted to ensure their functionality and effectiveness.
HVL (Half Value Layer) is the concept behind the measurement of shielding thickness in radiation physics. 1 HVL is defined as the thickness of an absorber that will reduce the radiation intensity to half of its original value. Another measurement concept is the TVL (Tenth Value Layer), defined as the thickness of an absorber that will reduce the radiation intensity to one-tenth of its original value.
	OT surgical staff wearing protective lead gown and thyroid shields during any examination is an example of radiation protection shielding measure. It is recommended that protective aprons containing at least 0.5mm of lead, which is equivalent to two HVLs, would reduce occupational exposure to about 25%. It is hence advisable to wear thyroid shield as the dose to the thyroid can be as high as 1.7 times as recorded by the thermoluminescent dosimeter (TLD) worn at the collar.
Figure shows radiographer wearing the shielding devices (anterior view)		Figure shows radiographer wearing the shielding devices (posterior view)