Assessing environmental and radiological impacts and lithological mapping of beryl-bearing rocks in Egypt using high-resolution sentinel-2 remote sensing images

Abstract

Emerald and other beryls represent a family of the most valuable gemstone around the world and particularly in Egypt. Beryllium (Be) contents in beryl-bearing bedrocks in south Sinai (Wadi Ghazala and Wadi Sedri), and in central and south Eastern Desert of Egypt (Igla area, Zabara-Um Addebaa belt, Homret Akarem, and Homret Mukpid) were investigated in this study. The environmental risk levels of Be, associated major ions, and heavy metals in groundwater nearby to beryl-bearing mineralization were also evaluated. Results showed that Be contents ranged from 1 to 374 ppm in beryl-bearing bedrocks, while in nearby groundwater, Be content has a range of 0.0001–0.00044 mg/L with an average of 0.00032 mg/L, which is within the permissible levels and below (0.004) the U.S. EPA maximum contaminant level (MCL). Most levels of heavy metals (e.g., Be, B, Ni, V, Fe, and Al) in the investigated groundwater of central and south Eastern Desert and south Sinai are within the permissible levels and below their corresponding U.S. EPA MCLs. This study also investigated the radiological risk of natural radionuclides distributed in beryl-bearing bedrocks in the study area using gamma spectrometry; Sodium Iodide [NaI(Tl)] scintillation detector. Among the estimated mean 238U, 232Th, and 226Ra activity concentrations of the studied beryl-bearing rocks, Homret Mukpid (79, 87.15, 60.26 Bq kg−1) and Homret Akarem (111.6, 51.17, 85.1 Bq kg−1) contain the highest values. This may be attributed to their highly fractionated granitic rocks that host uranium and thorium reservoir minerals such as zircon, allanite, and monazite. The estimated data of multi-radiological parameters such as absorbed gamma dose, outdoor and indoor annual effective dose, radium equivalent activity, internal and external indices, index of excess cancer, and effective dose to human organs reflecting no significant impacts from the emitted natural gamma radiation.

Spatio-Temporal Variation of Cyanobacteria Blooms in Taihu Lake Using Multiple Remote Sensing Indices and Machine Learning

“…The Sentinel-2 satellite provides high-spatial-and -temporal-resolution multispectral imagery of the world, with 13 bands with resolutions of 10 m, 20 m, and 60 m [43]. Considering the relatively high spatial resolution, the Sentinel-2 image was selected as the validation reference for extracting the cyanobacteria-affected water surface from the MODIS data [44].…”

Petrogenesis and geological implications of the trachytic rocks in the South Eastern Desert, Egypt: Mineralogical, geochemical, and radioactivity insights

“…The composition of Palaeozoic and Mesozoic volcanic rocks ranges from olivine basalt to trachyte, whereas tertiary volcanic formations are mostly basaltic. There have been numerous prior research on these alkaline volcanic systems conducted by (Heikal 2003; Dawood et al 2003; Saleh et al 2004, 2007, 2015, 2020, 2021; Ibrahim et al 2005; Abdalla 2001; El Tohamy 2011; Gharib et al 2012; Nabawy and El Sharawy 2018; Sadek et al 2020; Sallam et al 2021; Abuamarah and Nabawy 2021; Kamar et al 2022; Oraby et al 2022; Ali-Bik et al 2022; Abdalla et al 2023; Dessouky and Ali 2018; Dessouky et al, 2023; Khaleal et al 2022, 2023).…”