Cyril Schandorf

Natural radioactivity levels of some medicinal plants commonly used in Ghana

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.

Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: Results from IAEA projects

PURPOSE The objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. MATERIALS AND METHODS This prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. RESULTS The fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5 mGy (mean and range 0.59-3.2 mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. CONCLUSIONS Poor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography.

Patient dose assessment due to fluoroscopic exposure for some selected fluoroscopic procedures in Ghana

Organ and effective doses to 90 patients undergoing some selected fluoroscopic examinations at the Korle-Bu Teaching Hospital were estimated using the Monte Carlo-based program (PCXMC version 1.5). Radiation dose was estimated from free-in-air measurements. The mean effective doses were found to be 0.29 +/- 0.07, 0.84 +/- 0.13, 3.15 +/- 0.44, 6.24 +/- 0.70 and 0.38 +/- 0.05 mSv for urethrogram, barium swallow, barium meal, barium enema and myelogram examinations, respectively. The dose area product was estimated to be 3.55 +/- 0.95, 16.44 +/- 2.60, 50.81 +/- 7.04, 99.69 +/- 10.85 and 9.32 +/- 0.99 Gy cm(2) for urethrogram, barium swallow, barium meal, barium enema and myelogram examinations, respectively. Optimisation of procedures is required for barium enema and barium meal examinations.

RADIATION DOSES AND HAZARDS FROM PROCESSING OF CRUDE OIL AT THE TEMA OIL REFINERY IN GHANA

Processing of crude oil has been carried out in Ghana for more than four decades without measures to assess the hazards associated with the naturally occurring radionuclides in the raw and processed materials. This study investigates the exposure of the public to (226)Ra, (232)Th and (40)K in crude oil, petroleum products and wastes at the Tema oil refinery in Ghana using gamma-ray spectrometry. The study shows higher activity concentrations of the natural radionuclides in the wastes than the crude oil and the products with estimated hazard indices less than unity. The values obtained in the study are within recommended limits for public exposure indicating that radiation exposure from processing of the crude oil at the refinery does not pose any significant radiological hazard but may require monitoring to establish long-term effect on both public and workers.

Quality Assurance and Quality Control of Equipment in Diagnostic Radiology Practice-The Ghanaian Experience

The World Health Organization (WHO) defines a quality assurance (QA) programme in diagnostic radiology as an organized effort by the staff operating a facility to ensure that the diagnostic images produced are of sufficiently high quality so that they consistently provide adequate diagnostic information at the lowest possible cost and with the least possible exposure of the patient to radiation: (World Health Organization [WHO], 1982). The nature and extent of this programme will vary with the size and type of the facility, the type of examinations conducted, and other factors. The determination of what constitutes high quality in any QA programme will be made by the diagnostic radiology facility producing the images. The QA programme must cover the entire X-ray system from machine, to processor, to view box. Quality assurance actions include both quality control (QC) techniques and quality administration procedures. QC is normally part of the QA programme and quality control techniques are those techniques used in the monitoring (or testing) and maintenance of the technical elements or components of an X-ray system. The quality control techniques thus are concerned directly with the equipment that can affect the quality of the image i.e. the part of the QA programme that deals with instrumentation and equipment. An X-ray system refers to an assemblage of components for the controlled production of diagnostic images with X-rays. It includes minimally an X-ray high voltage generator, an X-ray control device, a tube-housing assembly, a beam-limiting device and the necessary supporting structures. Other components that function with the system, such as image receptors, image processors, automatic exposure control devices, view boxes and darkrooms, are also parts of the system. The main goal of a QC programme is to ensure the accuracy of the diagnosis or the intervention (optimising the outcome) while minimising the radiation dose to achieve that objective In a typical diagnostic radiology facility, QC procedures may include the following: a. Acceptance test and commissioning Acceptance test is performed on new equipment to demonstrate that it is performing within the manufacturer’s specifications and criteria (and also to confirm that the equipment meets

Systematic approach to training occupationally exposed workers in Ghana and the rest of Africa.

The International Basic Safety Standards requires that all personnel on whom protection and safety depends be trained and qualified. The Radiation Protection Institute of the Ghana Atomic Energy Commission has adopted a systematic approach to training those occupationally exposed to ionizing radiation in the course of their work. In collaboration with the International Atomic Energy Agency several training courses have been implemented at the national level and in the African region. From 1993 to 2008, more than 400 occupationally exposed workers in Ghana were trained on radiation safety. Several African regional training events on radiation safety have also been executed with a total participation number of 583 individuals. The training events have contributed towards upgrading the safety culture within institutions that have participated.

Medical physics practice and training in Ghana

Medical physics has been an indispensable and strategic stakeholder in the delivery of radiological services to the healthcare system of Ghana. The practice has immensely supported radiation oncology and medical imaging facilities over the years, while the locally established training programme continues to produce human resource to feed these facilities. The training programme has grown to receive students from other African countries in addition to local students. Ghana has been recognised by the International Atomic Energy Agency as Regional Designated Centre for Academic Training of Medical Physicists in Africa. The Ghana Society for Medical Physics collaborates with the School of Nuclear and Allied Sciences of the University of Ghana to ensure that training offered to medical physicists meet international standards, making them clinically qualified. The Society has also worked together with other bodies for the passage of the Health Professions Regulatory Bodies Act, giving legal backing to the practice of medical physics and other allied health professions in Ghana. The country has participated in a number of International Atomic Energy Agencys projects on medical physics and has benefited from its training courses, fellowships and workshops, as well as those of other agencies such as International Organization for Medical Physics. This has placed Ghanas medical physicists in good position to practice competently and improve healthcare.

Optimization of radiation protection for the control of occupational exposure in Ghana

Investigation of the optimization of protection of occupational exposed workers (OEWs) in Ghana had been carried out on the three practices in the country, namely medical applications, industrial radioisotope applications and research and education from 2002 to 2007. Mean annual effective dose and collective effective dose were estimated from dosimetry records from the Radiation Protection Institute of those occupationally exposed from 2002 to 2007. The mean annual effective dose estimated for about 650 OEWs per year ranged from 0.42 to 0.68 mSv compared with a global value of 0.5 mSv estimated by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2008 Report). This implies that efforts should still be made to institute as low as reasonably achievable culture in most practices in Ghana even though trend of doses incurred was low. The collective effective dose for this same period estimated ranged from 0.26 to 0.47 man Sv. A reference monetary value of the man sievert was estimated using the human capital approach for each year from 2002 to 2009; it ranged from 172 to 22 US

The Natural Radioactivity in groundwater from selected areas in Greater Accra region of Ghana by gross alpha and gross beta measurements

per man Sv, which provided a basis for estimating the cost of averting a unit collective effective dose of 1 man Sv. This value could not be used for quantitative optimization since the range of mean annual effective dose estimated was below 1 mSv.

Personal dose analysis of TLD glow curve data from individual monitoring records

Gross alpha and gross beta in 26 groundwater samples from Adentan to Abokobi areas in the Greater Accra Region of Ghana were determined using Alpha/Beta counting system (Canberra iMatic TM ). The average activity concentrations of gross alpha and gross beta were 0.034 and 0.501 Bq/L for Adentan, and 0.066 and 0.470 Bq/L for Abokobi, respectively. The results obtained are below the guideline levels of gross alpha (0.5 Bq/L) and gross beta (1.0 Bq/L) in drinking water established by the World Health Organisation. These results show that consumption of groundwater for the study areas may not pose any significant radiological health hazards through ingestion to the population.