The aims of this study were to investigate the frequency of computed tomography (CT) examinations for paediatric patients below 15 y of age in 128 CT facilities in 28 developing countries of Africa, Asia and Eastern Europe and to assess the magnitude of CT doses. Radiation dose data were available from 101 CT facilities in 19 countries. The dose assessment was performed in terms of weighted CT dose index (CTDI(w)), volume CT index and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods. The results show that on average the frequency of paediatric CT examinations was 20, 16 and 5 % of all CT examinations in participating centres in Africa, Asia and Eastern Europe, respectively. Eleven CT facilities in six countries were found to use adult CT exposure parameters for paediatric patients, thus indicating limited awareness and the need for optimisation. CT images were of adequate quality for diagnosis. The CTDI(w) variations ranged up to a factor of 55 (Africa), 16.3 (Asia) and 6.6 (Eastern Europe). The corresponding DLP variations ranged by a factor of 10, 20 and 8, respectively. Generally, the CTDI(w) and DLP values in Japan are lower than the corresponding values in the three regions in this study. The study has indicated a stronger need in many developing countries to justify CT examinations in children and their optimisation. Awareness, training and monitoring of radiation doses is needed as a way forwards.

Natural radioactivity levels in some selected medicinal plants commonly used in Ghana from the Centre for Scientific Research into Plant Medicine were investigated to determine the activity concentration and the annual committed effective dose due to naturally occurring radionuclides of 238U, 232Th and 40K. The activity concentration was determined using gamma-ray spectrometry. The results of the analysis indicated an average activity concentration of 238U, 232Th and 40K in the medicinal plants to be 31.8±2.8 Bq kg-1, 56.2±2.3 Bq kg-1 and 839.8±11.9 Bq kg-1 respectively. Khaya ivorensis recorded the highest activity concentration of 238U and 232Th while Lippia multiflora recorded the highest activity concentrations of 40K. The total annual committed effective doses ranged from 0.026±0.001 to 0.042±0.002 mSv a-1 with an average value of 0.035±0.001 mSv a-1. The average annual committed effective dose due to ingestion of the natural radionuclides in the medicinal plant samples were far below the world average annual committed effective dose of 0.3 mSv a-1 for ingestion of natural radionuclides provided in UNSCEAR 2000 report. Therefore, the radiological hazard associated with intake of the natural radionuclides in the medicinal plants is insignificant. The results provide baseline values which may be useful in establishing rules and regulations relating to radiation protection as well as developing standards and guidelines for the use of medicinal or herbal plants to the appropriate authorities.

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The purpose of this prospective study at 73 facilities in 18 countries in Africa, Asia and Eastern Europe was to investigate if the CT doses to adult patients in developing countries are higher than international standards. The dose assessment was performed in terms of weighted computed tomography dose index (CTDIw) and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods. Except in one case, the mean CTDIw values were below diagnostic reference level (DRL) while for DLP, 17 % of situations were above DRLs. The resulting CT images were of adequate quality for diagnosis. The CTDIw and DLP data presented herein are largely similar to those from two recent national surveys. The study has shown a stronger need to create awareness and training of radiology personnel as well as monitoring of radiation doses in many developing countries so as to conform to the ALARA principle.