Shielding assessment in three diagnostic X-ray facilities in Asaba, South-South Nigeria: how compliant are we to radiation safety?

Akintayo Daniel Omojola, Michael Onoriode Akpochafor, Samuel Olaolu Adeneye, Azuka Anthonio Agboje, Isiaka Olusola Akala


Introduction. Shielding is an important aspect of radiation protection, intending to ensure the safe use of ionising radiation. 

Aim and objectives.  This study is aimed at determining the instantaneous dose rate (IDR) and annual dose rate (ADR) to occupationally exposed workers within controlled areas and other staff/persons within the supervised areas in the three X-ray units. The objective was to compare the shielding design goals (P) in both classified areas mentioned above with recommended standards. 

Materials and methods.  Three X-ray facilities denoted as centre A, B and C were used. The equipment used in this study was two floor-mounted X-ray systems and one mobile X-ray unit. A calibrated survey meter was positioned at about 30cm from each barrier at various points to determine the average shielded air kerma. 

Results.  The mean background radiation in the three facilities was 0.10µSv/hr. The mean IDR to the controlled and supervised areas in centre A was 0.254±0.15 and 0.162±0.05µSv/hr, centre B: 0.524±0.73 and 0.154±0.05µSv/hr, and centre C: 0.322±0.20 and 0.147±0.07µSv/hr respectively. The mean shielding design goal (P) to the controlled areas in centre A, B and C was 0.712±0.42, 1.466±2.04 and 0.901±0.56mSv/yr, respectively. Similarly, the mean shielding design goal (P) for the supervised areas for centre A, B and C was 0.455±0.15, 0.431±0.15 and 0.410±0.19mSv/yr, respectively. The ADR to a radiographer behind the mobile screen in centre A, B and C was 1.394, 4.480 and 1.341mSv/yr, respectively. 

Conclusion.  The mean ADR and shielding design goals in the controlled and supervised areas from the three studied X-ray units were within acceptable limits for occupationally exposed staff and the public.


controlled areas, supervised area, shielding design goal, personnel, dose rate

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The South African Radiographer | ISSN 0258 0241

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