Evaluation of 1.5mm Lead Shield for Radiological Protection and Comparison of Calculated and Measured Results of Equivalent Dose

Abstract

Evaluation of radiation protective devices in radiology departments is one of the practices that ensure radiation protection and staff and patients safety in hospitals. A research work to evaluate 1.5mm lead shield used for radiological protection was carried out in Radiological Unit of Sharda  Hospital, of Sharda University, India, using 300mA fixed x-ray machine room. The evaluation was done in the x-ray energy (kVp) range between 52- 81 and by using calculative procedure and by direct measurement of the radiation dose rates. The two results were compared. The results
shows that, in the absence of the shield, only 11.82% of the radiation exposure was attenuated by the air space before reaching the  radiographer’s stand, while in the presence of the shield, 96.50% was attenuated, whereas, for the measured result only 10.17% was attenuated in the absence of the shield and 89.83% was attenuated in the presence of the shield before reaching the radiographer’s stand. The unit of radiation exposure was converted to that of equivalent dose and that of effective dose in order to assess the radiographer’s safety level behind the shield. It was found that, the equivalent/effective dose is as low as to be accepted according to the policy of ALARA (As Low As Reasonably Achievable), and within the NCRP recommended limit. This guaranteed the effectiveness of the lead shield of 1.5mm thickness in the x-ray energy range used in this study.

Keywords: Lead shield, radiological protection, effectiveness of 1.5mm leadshield, presence of shield, absence of shield, radiographer’s safety.