Margaret Idongesit ANİZOR, Akintayo Daniel OMOJOLA, Chibuzo Bede MADU, Mary-Ann Etim EKPO, Michael Onoriode AKPOCHAFOR, Samuel Olaolu ADENEYE, Ukeme Pius ANİEKOP

Personnel radiation dose assessment using a novel dosimeter in the department of radiology and dentistry in a medical facility in Delta State, South-South Nigeria: our experience in the last 4 years

Objectives. Large percentages of X-ray facilities in Nigeria do not use radiation monitoring device; a fewpercentage that use them do not evaluate or carryout out assessment programs to ascertain the detriment tooccupationally exposed workers. This study was aimed at evaluating dose reports from 2013 to 2016 forpersonnel who operate radiation facilities and those that work within radiation field during certain X-rayprocedures/examinations in the department of radiology and dentistry respectively; to ascertain if there iscorrelation between personnel dose and workload in both department and to determine if dose records arewithin acceptable limit recommended by the International Atomic Energy Agency (IAEA) safety series.Methods. Direct Ion Storage (DIS) dosimeter was used for a total of 35 occupationally exposed personnel whowork in the department of radiology and dentistry. The DIS dosimeter was read every two months and resultswere authomatically saved on the instadoseTMplatform. Results. The mean (total) dose in radiology departmentfor the first, second, third and fourth year was 0.17 ± 0.08 (3.52) mSv, 0.08 ± 0.03 (0.77) mSv, 0.07 ± 0.04(0.72) mSv and 0.07 ± 0.05 (0.55) mSv and in Dentistry was 0.08 ± 0.02 (0.73) mSv, 0.05 ± 0.02 (0.42) mSv,0.05 ± 0.02 (0.24) mSv and 0.07 ± 0.04 (0.34) mSv; respectively. There was significant difference in meanpersonnel dose from 2013-2016 in Radiology (p=0.028) and in Dentistry Department (p=0.004). Correlationof workload and personnel dose in Radiology (p=0.240) and Dentistry Department (p=0.765) wasn’t significant.There was no correlation in mean dose between both department (p=0.256). Conclusion. Overall mean dosein both department for occupationally exposed personnel were below IAEA annual dose limit of 20 mSvaveraged over a period of 5 consecutive years. Dose reports of personnel in both department reduced as theyear progressed due to radiation safety awareness

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[1] Frankel RI. Centennial of Röntgen’s discovery of x-rays. West J Med 1996;164:497-501.
[2] Wyman SM. Department of Radiology, Massachusetts General Hospital: a brief history. AJR Am J Roentgenol 1993;160:1141-4.
[3] Spiegel PK. The first clinical X-ray made in America--100 years. AJR Am J Roentgenol 1995;164:241-3.
[4] Mazrani W, McHugh K, Marsden PJ. The radiation burden of radiological investigations. Arch Dis Child 2007;92:1127-31.
[5] Pearce MS, Salotti JA, McHugh K, Metcalf W, Kim KP, Craft AW, et al. CT scans in young people in Northern England: trends and patterns 1993-2002. Pediatr Radiol 2011;41:832-8.
[6] International Atomic Energy Agency (IAEA). Applying radiation safety standards in diagnostic radiology and interventional procedures using x rays. Safety Reports Series No. 39: Vienna IAEA Publication; 2006.
[7] International Atomic Energy Agency (IAEA). Radiation protection and safety of radiation sources: international basic safety standards. IEAE Safety Standards Series No. GSR Part 3 (Interim): Vienna IAEA Publication; 2011.
[8] International Electrotechnical Commission (IEC). Medical electrical equipment-part 2-43: particular requirements for the safety of x-ray equipment for interventional procedures. IEC Report 60601. Geneva: IEC Publication; 2000.
[9] International Atomic Energy Agency (IAEA). Responsibilities and capabilities of a nuclear energy programme implementing organization. IAEA Nuclear Energy Serıes No. NG-T-3.6: Vienna IAEA Publication; 2009.
[10] Shrader-Frechette K. Trimming Exposure Data, Putting Radiation Workers at Risk: Improving Disclosure and Consent through a National Radiation Dose-Registry. Am J Public Health 2007;97:1782-6.
[11] Cardis E, Gilbert ES, Carpenter L, Howe G, Kato I, Armstrong BK, et al. Effects of low doses and low dose rates of external ionizing radiation: cancer mortality among nuclear industry workers in three countries. Radiat Res 1995;142:117-32.
[12] Wang JX, Inskip PD, Boice JD Jr, Li BX, Zhang JY, Fraumeni JF Jr. Cancer incidence among medical diagnostic X-ray workers in China, 1950 to 1985. Int J Cancer 1990;45:889-95.
[13] Akpochafor MO, Omojola AD, Soyebi KO, Adeneye SO, Aweda MA, Ajayi HB. Assessment of peak kilovoltage accuracy in ten selected X-ray centers in Lagos metropolis, South-Western Nigeria: A quality control test to determine energy output accuracy of an X-ray generator. J Health Res Rev 2016;3:60-5.
[14] Eze CU, Abonyi LC, Njoku J, Irurhe NK, Olowu O. Assessment of radiation protection practices among radiographers in Lagos, Nigeria. Niger Med J 2013;54:386-91.
[15] Okaro AO, Ohagwu CC, Njoku J. Evaluation of personnel radiation monitoring in radiodiagnostic centres in South Eastern Nigeria. African J of Basic & Appl Sci 2010;2:49-53.
[16] Eze KC, Nzotta CC, Marchie TT, Okegbunam B, Eze TE. The state of occupational radiation protection and monitoring in public and private X-ray facilities in Edo state, Nigeria. Niger J Clin Pract 2011;14:308- 10.
[17] Pejović S, Bosnjakovic P, Ciraj-Bjelac O, Pejović M. Characteristics of a pMOS suitable for use in radiotherapy. Appl Radiat Isot 2013;77:44- 9.
[18] Gladstone DJ, Lu XQ, Humm JL, Bowman HF, Chin LM. A miniature MOSFET radiation dosimeter probe. Med Phys 1994;21:1721- 8.
[19] Yasuda H. Responses of a direct ion storage dosimeter (DIS-1) to heavy charged particles. Radiat Res 2001;156:805-8.
[20] Kahilainen J. The direct ion storage dosimeter. Radiat Prot Dosim 1996;66:459-62.
[21] Wernli C. Dosimetric characteristics of a novel personal dosimeter based on direct ion storage (DIS). Radiat Prot Dosim 1996;66:23-8.
[22] Wernli C. Direct ion storage (DIS) Dosimeters for individual monitoring. Radiat Prot Dosim 1998;77:253-6.
[23] Kosunen A, Vartianinen E, Hyvönen H, Rantanen E, Kahilainen J. Testing of a TLD and a Direct Ion Storage (DIS) dosemeter for use as a personal dosemeter. Radiat Prot Dosim 1996;66:29-32.
[24] Kron T. Thermoluminescence dosimetry and its applications in medicine--Part 1: Physics, materials and equipment. Australas Phys Eng Sci Med 1994;17:175-99.
[25] Yukihara EG, McKeever SW. Optically stimulated luminescence (OSL) dosimetry in medicine. Phys Med Biol 2008;53:R351-79.
[26] The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann ICRP 2007;37:1- 332.
[27] 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann ICRP 1991;21:1-201.
[28] Jabeen A, Munir M, Khalil A, Masood M, Akhter P. Occupational exposure from external radiation used in medical practices in Pakistan by film badge dosimetry. Radiat Prot Dosim 2010;140:396-401.
[29] Nassef MH, Kinsara AA. Occupational radiation dose for medical workers at a University Hospital. JTUSCI 2017;11:1259-66.
[30] Gray, JE, Bailey ED, Ludlow J. Dental staff doses with handheld dental intraoral X-ray units. Health Phys 2012;2:137-42.