Khaled S A L A H E L D I N Ibrahiem | South Valley University (original) (raw)

Papers by Khaled S A L A H E L D I N Ibrahiem

Gamma-ray spectrometer and Lucas cell were used to evaluate the activity concentrations of 226 Ra... more Gamma-ray spectrometer and Lucas cell were used to evaluate the activity concentrations of 226 Ra, 232 Th, 40 K, and 222 Rn mass exhalation rates for 37 topsoil samples from different sites in Aswan city, Aswan-Abu Simbel highway, and Abu Simbel village,

Forty-nine different samples (crude oil, surface soil, produced water and sludge) from onshore oi... more Forty-nine different samples (crude oil, surface soil, produced water and sludge) from onshore oil fields in the Western Desert of Egypt were assessed for naturally occurring radioactive material (NORM) levels using HPGe gamma-ray spectrometer. The average activity concentrations of 226

Background: Radon is one of the most important radionuclides, formed from the decay of the elemen... more Background: Radon is one of the most important radionuclides, formed from the decay of the element radium and more soluble in water. As drinking water is a vital source of life, control of its quality is critical. Drinking water containing high radon levels presents a serious risk to human health. Thus awareness of radon levels in drinking water is extremely significant to protect against radiation exposure. We measured 222 Rn concentrations in different types of drinking water from Qena city, Egypt. Materials and Methods: 111 water samples were collected from various sources in Qena city (77 samples of household tap water, 14 samples of bottled water and 20 samples from municipal public water supply locations). The 222 Rn concentrations were determined using an AlphaGUARD radon gas analyzer. We calculated annual effective dose due to ingestion and inhalation of 222 Rn present in these waters. Results: 222 Rn concentration ranges were as follow: 22.0±0.7 to 118±3 mBq l-1 , from tap water 14±3 to 237±5 mBq l-1 from bottled water and 6.0±0.5 to 30.0±0.9 mBq l-1 from municipal public supplies. The annual effective dose due to inhalation and ingestion of 222 Rn in all types of drinking water measures less than the recommended reference level of 100 µSv y-1. Conclusion: Based on the obtained results, 222 Rn concentrations in the studied water samples were less than the permitted concentrations of USEPA and WHO guidelines.

AlphaGUARD radon gas analyzer and NaI (Tl) spectrometer were used to measure the concentration le... more AlphaGUARD radon gas analyzer and NaI (Tl) spectrometer were used to measure the concentration levels of 222 Rn and, 226 Ra, 232 Th, and 40 K respectively in 109 groundwater samples collected from four different districts in Qena governorate, Egypt. The average values of the activity concentration were 3.57 ± 0.08, 0.54 ± 0.03, 0.40 ± 0.03, and 5.10 ± 0.44 Bql À1 for 222 Rn, 226 Ra, 232 Th, and 40 K, respectively. The average values of 222 Rn, 226 Ra, and 232 Th are lower than, 100, 1, and 1 Bql À1 , respectively, the WHO recommended permissible levels for drinking water. For radiation exposure assessment, the annual effective doses due to ingestion of 226 Ra and 232 Th and inhalation of 222 Rn for adults were determined and compared with the reference limits. The annual effective doses due to ingestion 139.21-201.34 mSvy À1 are higher than the public annual dose limit 100 mSvy À1 recommended by WHO. These indicate that the ingestion of groundwater from the study areas might pose radiological health hazards.

Sorites marginalis as one of the benthic foraminifer's genera were collected from three coastal l... more Sorites marginalis as one of the benthic foraminifer's genera were collected from three coastal lagoons (Abu Shaar, Umm al-Huwaytāt, and Marsa Shūni) on the Egyptian Red Sea coast and investigated for their 226 Ra, 232 Th, and 40 K content using HPGe gamma-ray spectrometry. S. marginalis shells show high radioactivity levels with average activity concentration values of 251.

Four different grain size fractions (0.2-0.5, 0.5-1, 1-1.8, 1.8-2 mm) of red brick and cement mor... more Four different grain size fractions (0.2-0.5, 0.5-1, 1-1.8, 1.8-2 mm) of red brick and cement mortar samples at different moisture (0%, 5%, 10%, 15%, 20%) content relative to the sample mass were subjected to measuring their 222 Rn mass exhalation rates using Alpha-Guard radon monitor, PQ 2000 PRO. The results indicated an inverse proportion between the exhalation rate and the particles size. For all studied grain size fractions, the change of the moisture content clearly affected the 222 Rn mass exhalation rates. The exhalation rate reached its maximum value, which is two times higher than its value for the dry sample, by increasing the moisture content from 0 to 15% for red brick and from 0 to 5% for cement mortar, respectively. The current study results showed good agreement with those reported in the literature.

An intercomparison of the methodology (alpha, beta and gamma spectrometry) used for 238 U, 235 U ... more An intercomparison of the methodology (alpha, beta and gamma spectrometry) used for 238 U, 235 U and 210 Pb determination was carried out based on 38 sediment samples. The activity range of the samples varied from 10-700 Bq/kg for 210 Pb, 1-35 Bq/kg for 235 U and 10-800 Bq/ kg for 238 U. Results obtained using the three methods were not statistically different at high activity levels, but agreement between the results decreased at lower sample activity levels. For 210 Pb, the smallest difference was found between alpha and gamma spectrometry. A good correlation between results from alpha and gamma spectrometry was observed over the whole activity range. In beta spectrometry, the results were slightly higher than those obtained by alpha or gamma spectrometry due to the impurity of 228 Ra. In 238 U analysis, good correspondence was observed between 238 U determined by gamma and alpha spectrometry, particularly at higher 238 U activity concentrations over 100 Bq/kg. In 235 U analysis, attention needs to be paid to interference from 226 Ra and its reduction.

A high-resolution gamma-ray spectrometer was applied to measure the activity concentration of nat... more A high-resolution gamma-ray spectrometer was applied to measure the activity concentration of natural and artificial radionuclides 226 Ra, 232 Th, 40 K, and 137 Cs in 14 brands of infants powdered milk consumed in Egypt. The average activity concentrations were 0.91 ± 0.20, 0.60 ± 0.11, 477 ± 25 and 0.42 ± 0.11 Bq kg −1 for 226 Ra, 232 Th, 40 K, and 137 Cs, respectively. The total annual effective dose for different infant's age groups is estimated and also the total risk has been assessed. The results indicate that the consumption of the studied powdered milk would not pose any significant radiological impact to the infants.

The activity concentrations of 210 Pb and 210 Po in the most popular cigarettes and moassel tobac... more The activity concentrations of 210 Pb and 210 Po in the most popular cigarettes and moassel tobacco brands consumed in Egypt were determined by the spontaneous deposition method using alpha spectrometry. It turned out that the activity concentration of 210 Po was higher than that of 210 Pb in all tobacco brands. Higher activity concentrations for both 210 Pb and 210 Po were found in cigarette than in moassel tobacco. The average activity concentrations of 210 Pb and 210 Po in cigarette tobacco were 11.79 ± 1.67 and 15.00 ± 1.83 mBq cig −1 , respectively, whereas in moassel tobacco the values were 7.08 ± 1.91 and 9.12 ± 1.12 mBq g −1 , respectively. The daily activities inhaled in the lung of a smoker and the inhalation effective doses due to cigarette and shisha smoking were calculated. The results revealed that the total 210 Pb and 210 Po daily activities inhaled and the total annual inhalation effective doses due to shisha smoking were two times greater than the corresponding values due to cigarette smoking. Also, the results indicated that the annual effective doses from inhalation of 210 Pb and 210 Po due to smoking 20 cigarettes per day are 14 and 16 times greater than the annual ingestion doses from the diet, respectively. In contrast, the annual effective doses from inhalation of 210 Pb and 210 Po due to shisha smoking (27 g moassel tobacco per day) are 26 and 33 times greater than the annual ingestion doses from the diet, respectively. Keywords 210 Pb and 210 Po • Spontaneous deposition • Cigarettes and moassel tobacco • Activity inhaled • Egypt

The concentrations of the natural radionuclides 226 Ra, 232 Th and 40 K in 15 different water sam... more The concentrations of the natural radionuclides 226 Ra, 232 Th and 40 K in 15 different water samples from Elba protective area, southeastern desert of Egypt, have been determined using NaI(Tl) detector. Gamma ray spectrometric analysis was performed and the concentrations obtained for each of the radionuclides expressed in Bq l À1 ranging from 1.6 to 11.1 for 226 Ra, 0.21 to 0.97 for 232 Th and 9.1 to 23 for 40 K. A reasonable correlation was found between 226 Ra, 232 Th concentrations and pH, although no general trend was observed with conductivity and total dissolved solids. The mean effective doses of 0.56 mSv y À1 for 226 Ra, 0.065 mSv y À1 for 232 Th and 0.04 mSv y À1 for 40 K were estimated for the ingestion of these waters by adults.

External exposures of population to ionising radiation due to naturally occurring radionuclides i... more External exposures of population to ionising radiation due to naturally occurring radionuclides in sixty-three granite samples from three different locations in south eastern desert of Egypt were considered in this article. Average outdoor gamma dose rates in air were 190, 290 and 330 nGy h 21 for Elba, Qash Amir and Hamra Dome granites, respectively. The corresponding doses in indoor air are 270, 400 and 470 nGy h 21 , respectively. These average values give rise to annual effective dose (outdoor, indoor and in total) 0.24, 1.4 and 1.6 mSv for Elba granite. For Qash Amir and Hamra Dome granites the corresponding values were 0.35, 2 and 2.3 mSv and 0.41, 2.3 and 2.7 mSv, respectively.

In this work, the natural radionuclide concentrations of the 226 Ra, 228 Ra, 232 Th and 40 K were... more In this work, the natural radionuclide concentrations of the 226 Ra, 228 Ra, 232 Th and 40 K were estimated from samples of cattle and poultry fodder, South Valley University farms and Qena Governorate farm, Qena, Upper Egypt. The radionuclide concentrations and annual consumption rate of twenty-nine animal fodders were analyzed using low-level γ-spectrometer, including a mixture fodder, silage, hay, rice straw, and poultry fodder. The irradiation risk of human health was assessed due to indirect ingestion of the beef, milk, poultry and egg, the annual effective dose of the radionuclides for the local consumer was 2.7, 14, 0.1, and 0.14 µSv·y-1 , respectively.

Levels of 226,228 Ra, 232 Th, 210 Pb, 210 Po and 40 K in sediments from four monitoring areas, El... more Levels of 226,228 Ra, 232 Th, 210 Pb, 210 Po and 40 K in sediments from four monitoring areas, El Hamraween and Ras El Behar (Red Sea, Egypt) and LL3A and JML (Baltic Sea, Finland), have been investigated using alpha and gamma spectrometry. The average activity concentrations were 238+ + + + +4 Bq kg 21 (226 Ra), 215+ + + + +11 Bq kg 21 (210 Pb) and 311+ + + + +18 Bq kg 21 (210 Po) for El Hamraween area. In Ras El Behar area, the corresponding values were 16+ + + + +0.4, 18+ + + + +1 and 20+ + + + +5 Bq kg 21 , respectively. The activity concentrations for 226 Ra, 210 Pb and 210 Po (uranium series) in El Hamraween bottom sediment are much high compared with those in Ras El Behar area, which indicates the enhanced levels due to the activities of phosphate mining and shipment operations in El Hamraween area. Excluding the influence of phosphate mining activities, it can be concluded that the levels of radioactivity in Baltic Sea sediments are higher than those in Red Sea sediments.

Using high-resolution gray spectroscopy, the activity concentration of naturally occurring radion... more Using high-resolution gray spectroscopy, the activity concentration of naturally occurring radionuclides 226 Ra, 232 Th and 40 K was determined in hematite mineral samples from two different areas, Abu Aggag and Um Gereifat areas, in Eastern Desert of Egypt. The results indicated that all samples under investigation contain 226 Ra and 232 Th whereas 40 K could not be detected. The mean activity concentration values were 14 AE 0:2 and 10 AE 0:2 Bq=kg for 226 Ra and 232 Th, respectively, of samples from Abu Aggag area and 223 AE 7 and 42 AE 0:4 Bq=kg of samples from Um Gereifat. Radiological effects were calculated and the results are compared with the internationally accepted values. r

The present study reports the U(VI) uptake from solution on a Ti-rich Egyptian black sand, showin... more The present study reports the U(VI) uptake from solution on a Ti-rich Egyptian black sand, showing that the crystal surfaces exhibit a marginal influence to the total process of U(VI) uptake onto Ti-containing micro-and mesoporous silicate materials. The results were evaluated using Lagergren first order equation and the apparent thermodynamic parameters of uranium uptake onto the considered materials were calculated.

The concentration of 210 Po was determined in different foodstuffs of plant origin purchased from... more The concentration of 210 Po was determined in different foodstuffs of plant origin purchased from markets in Qena City, Upper Egypt. Measurement of 210 Po has been carried out using alpha spectrometry technique in different food categories such as vegetables, fruits, cereals beverages and herbs. The general range of 210 Po activity levels ranged widely from b 0.010-18.6 ± 0.910 mBq g − 1 , with minimum being in cereal samples and maximum being in beverage samples. Tea samples recorded highest activity concentrations of 210 Po with lowest value of 10 ± 0.54 mBq g −1 for Crown tea and highest value of 18.6 ± 0.910 mBq g −1 for El maa-bad tea. The daily intake of 210 Po from food consumption reveals that vegetables are the biggest contributors, while beverages are the lowest. The effective ingestion dose has been estimated for Qena City residents and it was found in the range 0.008-38.3 μSv y −1 .

Isotopes of uranium in the seawater sediments collected from two different areas (El Hamraween ha... more Isotopes of uranium in the seawater sediments collected from two different areas (El Hamraween harbour and Ras El Behar) on the Egyptian coast of the red sea have been studied using radiochemical separation procedures and alpha-particle spectrometry. Activity concentrations of 238 U, 235 U, 234 U were calculated. The activities observed indicated enhanced radioactivity levels in seawater sediments of El Hamraween harbour area due to the activities of phosphate shipment operation. Secular equilibrium between 234 U and 238 U was found in the analyzed samples. The average activity ratio of 235 U/ 238 U was close to the value 0.046 for uranium in nature.

Natural radioactivity due to the presence of 226 Ra, 232 Th and 40 K in selected building materia... more Natural radioactivity due to the presence of 226 Ra, 232 Th and 40 K in selected building materials (cement, sand, bricks, gypsum and ceramic) used in Egypt was measured using a gamma-ray spectrometer with an HPGe detector. The average activity concentrations observed in different building materials ranged from 10.0 ± 1.3 to 109 ± 6, <2 to 55.8 ± 2.2 and 5.5 ± 1.7 to 684 ± 34 Bq kg −1 for 226 Ra, 232 Th and 40 K, respectively. Based on these, together with previously reported results, the effective doses received by the residents of different types of house within all Egyptian governorates were assessed using the WinMat computer program. The results were below 1 mSv a −1 in all cases. The collective effective dose indoors was assessed as 15 000 man Sv and the excess effective dose due to building materials was 0.07 mSv a −1 .

Radiogenic heat production data for phosphate rocks outcropping on the three main areas Eastern D... more Radiogenic heat production data for phosphate rocks outcropping on the three main areas Eastern Desert, Western Desert and Nile Valley are presented. They were derived from uranium, thorium and potassium concentration measurements of gamma radiation originating from the decay of 214 Bi (238 U series), 208 Tl (232 Th series) and the primary decay of 40 K. A low radioactive heat production rate (0.3270.1 mW m À3) was found for Wadi Hegaza, whereas the highest value (1974.1 mW m À3) was found for Gabel Anz, Eastern Desert of Egypt.