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    Assessing geochemical and natural radioactivity impacts of Hamadat phosphatic mine through radiological indices
    (Public Library Science, 2023) Fathy, Douaa; Zakaly, Hesham M. H. S.; Lasheen, El Saeed R.; Elsaman, Reda A.; Alarifi, Saad; Sami, Mabrouk; Awad, Hamdy
    The utilization of phosphorite deposits as an industrial resource is of paramount importance, and its sustainability largely depends on ensuring safe and responsible practices. This study aims to evaluate the suitability of phosphorite deposits for industrial applications such as the production of phosphoric acid and phosphatic fertilizers. To achieve this goal, the study meticulously examines the geochemical characteristics of the deposits, investigates the distribution of natural Radioactivity within them, and assesses the potential radiological risk associated with their use. The phosphorites are massive and collected from different beds within the Duwi Formation at the Hamadat mining area. They are grain-supported and composed of phosphatic pellets, bioclasts (bones), non-phosphatic minerals, and cement. Geochemically, phosphorites contain high concentrations of P2O5 (23.59-28.36 wt.%) and CaO (40.85-44.35 wt.%), with low amounts of Al2O3 (0.23-0.51 wt.%), TiO2 (0.01-0.03 wt.%), Fe2O3 (1.14-2.28 wt.%), Na2O (0.37-1.19 wt.%), K2O (0.03-0.12 wt.%), and MnO (0.08-0.18 wt.%), suggesting the low contribution of the detrital material during their deposition. Moreover, they belong to contain enhanced U concentration (55-128 ppm). They are also enriched with Sr, Ba, Cr, V, and Zn and depleted in Th, Zr, and Rb, which strongly supports the low detrital input during the formation of the Hamadat phosphorites. The high Radioactivity of the studied phosphorites is probably due to the widespread occurrence of phosphatic components (e.g., apatite) that accommodate U in high concentrations. Gamma spectrometry based on NaI (Tl) crystal 3x3 has been used to measure occurring radionuclides in the phosphorite samples. The results indicate that the radioactive concentrations' average values of Ra-226, Th-232, and K-40 are 184.18 & PLUSMN;9.19, 125.82 & PLUSMN;6.29, and 63.82 & PLUSMN;3.19 Bq Kg(,)(-1) respectively. Additionally, evaluations have been made of the radiological hazards. The calculated risk indicators exceeded the recommended national and world averages. The data obtained will serve as a reference for follow-up studies to evaluate the effectiveness of the Radioactivity of phosphatic materials collected from the Hamdat mine area.
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    Assessment of heavy metals contamination of sediments and surface waters of Bitter lake, Suez Canal, Egypt: Ecological risks and human health
    (Pergamon-Elsevier Science Ltd, 2023) Shetaia, Said A.; Nasr, Riham A.; Lasheen, El Saeed R.; Dar, Mahmoud A.; Al-Mur, Bandar A.; Zakaly, Hesham M. H.
    The concentrations of heavy metals in the surface waters and sediments of Bitter Lake were investigated to assess the level, distribution, and source of pollution and the associated ecological and human health risks. The ecological indices of the lake water indicate low contamination degrees by heavy metals. A dermal exposurebased health risk evaluation revealed no carcinogenic or non-carcinogenic impact on human health. The contamination factor (CF) for Cu, Ni, Pb, Mn, Fe, and Zn (CF < 1) indicate low contamination levels, while Cd reaches very high contamination in most sediment sites (CF ranges from 6.2 to 72.4). Furthermore, the potential ecological risk factor (Eri) and modified hazard quotient (mHQ) indicate low ecological risk for all metals except Cd, revealing high to very high-level ecological risk in most sites (Eri ranges from 185 to 2173 and mHQ from 1.8 to 6.3). This emphasizes the urgency of prompt actions to improve the environment in Bitter Lake.
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    Mineralogical constituents and radioactivity analysis of commercial granitic ornamental stones: Assessing suitability and radiation safety
    (Elsevier, 2023) Lasheen, El Saeed R.; Awad, Hamdy A.; Ene, Antoaneta; Alarifi, Saad S.; Rashwan, Mohammed A.; Kawady, Nilly A.; Issa, Shams A. M.
    Several commercial granitic rocks are widely used as decorative material (ornamental stones) due to their durability and fantastic colors. The present study aims to identify the mineralogical constituents as well as natural radioactivity of seven granitic rocks known as Gandonna, Pink Granite, Fantazia, Buff granites I, Buff granites II, Qusseir brown, red granites in order to deduce their suitability for different applications (decorative stone). Accordingly, in the petrographic investigation, the examined rocks comprise different proportions of essential minerals (potash feldspar, quartz, and albite) with some secondary minerals such as kaolinite and chlorite minerals. 238U, 226Ra, 232Th and 40K activity concentrations were detected by using NaI (Tl) scintillation & gamma;-ray technique. Fantasia (av. 4.13 & PLUSMN; 5.85, 10.77 & PLUSMN; 1.9 Bqkg ? 1), and Gandonna (av. 12.4 & PLUSMN; 10.12, 35.01 & PLUSMN; 3.81 Bqkg ? 1) samples have the lowest mean 238U, and 232Th activities value, relative to other rock samples, which are lower than the recommended levels of UNSCEAR. Except for absorbed dose rate, numerous radiological indices such as outdoor and indoor annual effective dose, radium equivalent activity, external and internal indices, excess lifetime cancer risk and organs of effective dose are calculated for the examined stations to deduce the radiation effects on human organs. The obtained results reveal that the natural gamma radiation from these rocks is within acceptable limits.
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    Physico-mechanical properties and shielding efficiency in relation to mineralogical and geochemical compositions of Um Had granitoid, Central Eastern Desert, Egypt
    (Frontiers Media Sa, 2023) Rashwan, Mohammed A.; Lasheen, El Saeed R.; Abdelwahab, Wael; Azer, Mokhles K.; Zakaly, Hesham M. H.; Alarifi, Saad S.; Ene, Antoaneta
    The current work aims to describe the physico-mechanical characteristics and shielding efficiency with reference to the mineralogical and geochemical compositions of the Neoproterozoic Um Had composite granitoid pluton in order to deduce their favorability as dimension stones. The Um Had granitoid pluton has an elliptical outline with a mean diameter of about 10 km. This pluton is a composite (ranging from white to reddish pink color), hard, massive, and medium- to coarse-grained granitoid body. It is classified as syenogranite according to their modal and bulk chemical compositions. Geochemically, the granitoid pluton is a highly calc-alkaline, peraluminous granite, formed by low degree partial melting of tonalitic source rock in a post-collisional tectonic setting. The physico-mechanical properties of the granitoid pluton under study satisfy the requirements of dimension stone in terms of their bulk density (from 2561 to 2564 kg/m3), and to some extent water absorption capacity (from 0.38% to 0.55%). However, their compressive strength values (50.4-113.4 MPa) do not achieve the minimum requirement for interior use and light duty exterior use. This study delves into the potential of some of our syenogranite samples (I, IIA, IIS, and 10) as gamma radiation shielding materials. We have assessed the mass attenuation coefficient (GMAC), effective atomic number (Zeff), exposure build-up factor (EBF), and energy absorption build-up factor (EABF) for each of these samples. The GMAC and Zeff calculations were performed using the Phy-X online software, across a photon energy range of 0.015-15 MeV. Our findings suggest an inverse relationship between photon energy and GMAC, with the highest values observed for the (I) granite sample (& SIM;18). This study shows the promising radiation shielding capacity of our samples. The insights derived from GMAC, Zeff, EBF, and EABF can serve as a guide for the development of effective, naturally sourced radiation shielding materials.