Isam Salih

Investigation of natural radioactivity levels in water around Kadugli, Sudan.

Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for (238)U, (226)Ra, (222)Rn, and (232)Th activity concentrations. The surface water showed very low levels of radionuclide concentrations: <1.0-7.5, 8.5-16.5, <1.6, and <0.1-0.39 mBq L(-1) for (238)U, (226)Ra, (222)Rn, and (232)Th, respectively. Groundwater revealed a significant amount of natural radioactivity (16.1-1720, 7.7-14.3, 3000-139,000, <0.1-39 mBq L(-1)) respectively. The overall annual effective dose was below the WHO reference dose level of 0.1 mSv yr(-1) except in one groundwater sample with an associated dose of 0.7 mSv yr(-1).

Survey of computed tomography technique and radiation dose in Sudanese hospitals

The purpose of this study was to survey technique and radiation absorbed dose in CT examinations of adult in Sudan and to compare the results with the reference dose levels. Questionnaire forms were completed in nine hospitals and a sample of 445 CT examinations in patients. Information on patient, procedure, scanner, and technique for common CT examinations were collected. For each facility, the radiation absorbed dose was measured on CT dose phantom measuring 16 cm (head) and 32 cm (body) in diameter and was used to calculate the normalized CT air kerma index. Volume CT air kerma index (CVOL), CT air kerma-length product (PKL,CT) values were calculated using the measured normalized CT air kerma index and questionnaire information. The effective dose, E estimates was determined by using PKL,CT measurements and appropriate normalized coefficients. Assuming the sample to offer a fair representative picture of CT practice patterns in Sudan, the mean CVOL and PKL,CT values were comparable or below the reference doses: 65 mGy and 758 mGy cm, respectively at head CT; 11.5 mGy and 327 mGy cm, respectively at chest CT; 11.6 mGy and 437 mGy cm, respectively at abdominal CT; and 11.0 mGy and 264 mGy cm, respectively at pelvis CT. Estimated effective doses were 1.6, 4.6, 6.6 and 4.0 mSv, respectively. The study offered a first national dose survey and provided a mean for quality control and optimization of CT practice within the country.

Radiation exposure of workers in storage areas for building materials

Abstract Radon levels and radioactivity were measured in 50 shops and storage areas for building materials in Sudan. Charcoal canister and gamma spectrometry systems were used to measure radon in 55 types of natural material, and concentrations of 71–292 Bq/m3 (mean, 154 ± 38 Bq/m3) were found. The concentration of radium (226Ra) ranged from 2.8 to 182.5 Bq/kg, of thorium (232Th) from 1.2 to 302 Bq/kg and of potassium (40K) from 82.3 to 1413.3 Bq/kg. Porcelain, ceramic and marble showed high values, while gravel types had low radioactivity. Radium in building materials was well correlated with radon (r2 = 0.77). The average annual dose of workers at these sites due to inhalation of radon was estimated to be 2.8 mSv. The activity index of building materials ranged between 0.33 and 1.97 (mean, 0.77).

Characterization of 222Rn and meteorological parameters in Uro houses at South Kordofan state

This study was carried out to assess and map indoor radon concentration and to estimate radiation dose in Uro town in Sudans South Kordofan state. A portable radon meter (RRA-01M-03), equipped with simple sensors of meteorological parameters has been used for carrying out radon measurement. The annual absorbed dose from the corresponding measured radon concentration was calculated using dose rate conversion factors of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The corresponding annual effective dose and equivalent dose to the lungs were estimated. Measured activity concentrations of 222Rn, annual absorbed dose, annual effective dose and equivalent dose to the lungs were found in the range 20–4482 Bq/m3, 0.32–70.67 mSv/y, 0.76–169.61 mSv−y and 0.16 × 10−7 to 35,856 × 3.5856 × 10−11 mSv−y, with geometric mean 109.43 Bq/m3, 1.73, 4.16 and 1.1 × 10−7 mSv−y, respectively. Upon comparing the results with global data, it was found with the exception of six samples, the obtained values fall far below the action level of 200–600 Bq/m3 recommended by the International Commission on Radiological Protection. However, the geometric mean is higher than the reported average global indoor radon concentration. Meteorological parameters were measured and no correlation was noted between radon concentration and these parameters. The overall annual effective dose was higher than the UNSCEAR recommended reference dose level of 1.0 mSv−y.

Radiation survey of aircraft and heavy machinery scrap.

This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of (90)Sr and one of (226)Ra in aircraft scrap. Of course, (90)Sr sources are used in military aircraft as temperature sensors while (226)Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1m from the source fall within the range of 25.1-40.2 μSv/h with an average value of 33.52 ± 4.06 μSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing.

RADIOLOGICAL HAZARD INDICES OF GRANITIC ROCKS USED FOR THE CONSTRUCTION OF BUILDINGS FROM NUBA MOUNTAINS SUDAN

This study was conducted to assess the level of radioactivity and the radiation hazards associated with granite rocks used for construction of buildings. The measurement of radioactivity content of the rock samples was performed with gamma-spectrometry equipped with Nal (TI) detector. From the results obtained in this study the average activity concentrations of 226Ra, 232Th and 40K were 20.64, 30.50 and 295.19 Bq kg-1, respectively. The absorbed dose rate in air at 1 m above ground level, the annual effective dose and the gamma index were determined with the aim to assess the possible radiological impact on inhabitants of dwellings built using such rocks. The mean value of the absorbed dose rate, the annual effective dose and the gamma index (Iγ) was 36.36 nGy h-1, 40.79 μSv y-1 and 0.51 μSv y-1, respectively. Radium equivalent activities, and external and internal hazard indices, were also calculated. These data indicated that the area of study lies within areas recognized as normal background radiation and the granite rocks are safe to be used as building material and other structural purposes.

Comparative Sequence Assessment of Optimised T2 and T2* Sequences for Quantification of Iron in Transfused Dependent Paediatric Sickle Cell Anaemia (SCA) Patients

Despite the fact that Sickle Cell Anaemia (SCA) patients undergo blood transfusion to reduce the risk of some complications associated with the disease, however, regular blood transfusion inevitably causes iron overload. In Sudan, the levels of iron in blood-transfused patients are regularly monitored using the serum ferritin, which is widely known to be an unreliable marker for body iron balance. The use of magnetic resonance imaging techniques such as theT2 and T2* sequences have demonstrated promising results in estimating iron concentration in transfused dependent patients Wood (Blood 106:1460–1465, 2005, [1]). There is however little data on the literature that systematically compared T2 and T2* in sickle cell anaemia (SCA) Wood (Am J Hematol 90:806–810, 2015, [2]). The aims of this work are to investigate two optimised T2 and T2* sequences, determine their viability for the quantification of iron in transfused dependent SCA and compare them to the standard serum ferritin method. The two optimised sequences were subsequently investigated on livers of 10 volunteers and 25 SCA paediatric patients using a 1.5T Philips scanner located at Al Ateeba Hospital in Khartoum State-Capital of Sudan. Ethical approval for the study was obtained from the National Ministry of Health-Health Research Council-Sudan. Linear correlation was found between T2* and serum ferritin (R2 = 0.949, P < 0.001), T2 and serum (R2 = 0.946, P < 0.001) and T2 and T2* measurements (R2 = 0.921, P = 0.789). The results demonstrate that both of the optimised T2 and T2* sequences could provide reliable measurements in the quantification of range of iron concentrations on transfused dependent paediatric SCA patients.

Radiation survey of an area suspected to be contaminated by depleted uranium released from industrial radiography camera

This case was undertaken to measure and identify radiation contamination in soil samples consist of waste generated from industrial radiography camera . Another aim of the present work is to raise awareness of the hazards of radiation among the public and worker of industrial radiography testing. Handheld radiation survey meters and gamma spectrometry based on high-purity germanium detectors (HPGe) have been used for radioactivity measurement. The survey has resulted in the detection of 238U, 235U and 137Cs in the samples. The values of 238U and 137Cs lie within the range 7.780-88.665 Bq/kg and 0.720-11.730 Bq/kgwith an average value of 33.003 ± 21.023 Bq/kg and 3.719 ± 2.767 Bq/kg respectively. The average value of the 238U in the current investigation was found to be higher than the reported world-wide data35 Bq/kg. 235U was detected in 9 samples out of 18 samples and ranged from 5.23-104.160 with an average value of 23.199 ± 32.072 Bq/kg. On the other hand, depleted uranium (DU) was investigated and found to be in 9 samples out of 18 on the basis of the natural 235U/238U activity ratio that was determined to be 0.046. The presence of depleted uranium could be attributed to the depleted uranium which are used in shielding of 192Ir in industrial radiography cameras. Based on the results, it can be concluded that the waste generated from industrial radiography cameras constitutes a serious source of DU contamination.