Radiation dose to the thyroid, eyes and parotid glands of patients undergoing intra-oral radiographic procedures in a teaching hospital in Ibadan, Oyo state Nigeria

Background: Intraoral radiographs are believed to deliver low doses to patients, thus little work has been done in this regards. Considering the increment in the number of patients reporting for the examination and the probability of delayed somatic effects for accumulated low doses of X-irradiation, it is expedient to determine the doses to three critical organs eye, thyroid and parotid that are at risk during exposure

Materials and Methods: Thermoluminescent dosimeters was used to measure Entrance Surfaces Doses [ESDs] to the thyroid, eye and parotids salivary gland of 40 adult patients undergoing intra-oral radiographic examination at University College Hospital, [UCH] Ibadan, Oyo state

Results: Results indicated entrance surface doses [ESD] ranged between 0.0447 mGy to 0.3898 mGy to the thyroid, 0.0742 mGy to 0.3989 mGy to eye and 0.0467 mGy to 0.4164 mGy to the parotids for the period of study. The mean ESD +/- SD to the thyroid, parotids and eyes for male were 0.179810.081, 0.215510.109 and 0.219710.081 mGy with the female patients 0.195710.084, 0.209110.081 and 0.228010.113 mGy respectively. No statistically significant difference was found between these means

Conclusion: The doses obtained in this study were lower than the documented threshold that could cause significant damage in the various organs, not undermining stochastic effect of radiation. This study will assist in setting Diagnostic Reference Level [DRL] for intraoral radiographic imaging in Nigeria

Estimation of radiation dose to the lens of eyes of patients undergoing cranial computed tomography in a teaching hospital in Osun state, Nigeria

One of the means of assessing dose to patients from Computed tomography [CT] procedure is through the determination of the skin entrance dose [ESD] with the appreciation of the concern that ocular exposure effects from CT scan includes possible induction of cancer and cataract. Due to the relatively more recent introduction of CT scans, little work has been done in this area in the country including exposure dose on the lens of the eyes of patients undergoing Cranial Computed Tomography [C-CT]. The Entrance Surface Dose [ESD] to the lens of eyes of 26 patients who had cranial CT procedures at a University Teaching Hospital in Ile-Ife, Nigeria has been determined in order to assess the level of radiation protection compliance and optimization of radiation safety at the hospital. Results indicate that the doses to the patients ranged between 17.13 mGy and 51.98 mGy within the period under study. The average doses obtained for the pediatric patients [1.5-18 yrs], young adults [19-49 yrs] and adults [>/= 50 yrs] were 31.14 +/- 11.02 mGy, 41.81 +/- 12.60 mGy and 31.97 +/- 11.31 mGy respectively. The mean dose obtained in this study was lower than threshold for lens damage, therefore the dose recorded in this study is clinically safe. This study represents a requisite pedestal on the need for a nation-wide evaluation and investigation of optimization of procedures in radiological examinations with a view to establishing a national dosimetry protocol and reference dose level or guidance level in the country

Activity concentrations of [232]Th, [226]Ra and [40]K and gamma radiation absorbed dose rate levels in farm soil for the production of different brands of cigarette tobacco smoked in Nigeria

Presently, the British-American Tobacco Company [BAT] located in Ibadan, Oyo State is the only tobacco producing company in Nigeria accounting for about nine different brands of cigarette tobacco smoked in the country. The tobacco leaves are produced from some farmlands located in Oke-Ogun area of Ibadan where special fertilizers are used for the growing of the tobacco leaves. The use of this fertilizer may enhance natural radionuclide contents in the farm soils and through root uptake be accumulated in the leaves. In this study, soil samples from three farmlands used for the production of the tobacco leaves were collected in order to determine the activity concentrations of [226]Ra, [232]Th and [40]K in the farm soil. Measurements for the determination of the activity concentrations were carried out using gamma-ray spectrometry comprising a lead-shielded 76 mm _ 76 mm NaI[Tl] detector crystal [Model 802 series, Bicron Nal] coupled to a Canberra series 10 plus multichannel analyzer [MCA] [model 1104] through an preamplifier base. Results of measurements showed that the average activity concentrations of the natural radionuclides in the soil samples across the three farms varied from 2550.4 +/- 154.6 to 3208.9 +/- 188.7 Bq kg[-1] for [40]K, 33.1 +/- 11.9 to 39.9 +/- 9.3 Bq kg[-1] for [226]Ra, while for [232]Th it varied between 51.98 +/- 8.4 and 56.08 +/- 17.51 Bq kg[-1]. The activity concentrations of these radionuclides and gamma absorbed dose rates due to the concentration of these radionuclides were found to be higher than world average values while those of the control farm values were lower to world averages and the tobacco leaf farms. From the results obtained the fertilizer type used on the farmlands for the tobacco leaf production was very rich in [40]K with typical values greater 2000 Bq kg-[1]. Also there may be possible high signatures of [210]Pb and [210]Po in the tobacco leaves and the cigarette samples smoked in the country. This is a subject for future research consideration given the fact that alpha radiation plays a major role in the etiology of lung cancer