SOURCE:

Faculty: Health Sciences And Technology
Department: Radiology

CONTRIBUTORS:

Anene, C. Nnamdi
Nzotta C. Christian

ABSTRACT:

Occupationally, radiographers are exposed to chronic low doses of ionizing radiation, hence it is important that they are regularly monitored and occupational dose kept as low as possible. This study determined the occupational dose to radiographers and their opinion to radiation protection measures in Anambra State. A prospective cohort survey of 60 radiographers who dispense ionizing radiation in both public and private centres, chosen from across Anambra state was conducted. After a short seminar on the need for monitoring, an adopted self-completion questionnaire was distributed to the radiographers on the first day to elicit data on their opinion on radiation protection in their places of employment. Afterwards, the radiographers were given first batch of labelled thermoluminescent dosimeter (TLD) chips which they wore outside the white laboratory coat, between the chest and abdomen. They wore the 1st batch of the TLDs for three months before it was collected from them and sent for reading. A 2nd batch of the TLDs were given to them which they also wore for three months before it was collected from them and sent for reading. The TLD chips were read at the Centre for Energy Research and Training Zaria using Harshaw 4500 TLD reader connected to a computer with winREMs software application. The mean effective dose of radiation received by radiographers in six months in Anambra state was 0.56 ± 0.03 mSv (range: 0.34 – 0.90 mSv) with an annual equivalence of 1.12 ± 0.06 mSv (range: 0.68 – 1.80 mSv). There was a significant (p<0.05) difference between radiographers in government-owned facility, whose doses are higher than those in privately owned centres (mean difference 0.17 mSv). Personnel monitoring was provided for 81.6% (n = 49) of the radiographers. Lead was used for shielding in all the centres studied (100%) while TLD which are seldom worn, dominated as the material of choice for personnel monitoring and are fairly read every six months on the average. Greater no (83.3%; n = 50) of the radiographers do not wear PPDs while working and only 26.7% (n = 16) are involved in annual radiation protection training. Radiation safety officers and certified physicists were not available in all the centres. In conclusion, the occupational annual dose in Anambra state is far below the ICRP set limit of 20 mSv averaged over 5 years. Despite the poor radiation monitoring conditions in Anambra state, the study has shown that work environment is safe and radiographers in Anambra state are not overly exposed to harmful effects of ionizing radiation occupationally.