Environmental implications and spatial distribution of natural radionuclides and heavy metals in sediments from four harbours in the Egyptian Red Sea coast

Heavy metal levels of outdoor dust from the Eastern Mediterranean Sea region and assessment of the ecological and health risk

As a result of some chemical element (heavy metals) pollution of dust, environmental pollution of dust has become an increasing concern, necessitating an assessment of risks to both ecology and human health, particularly in urban areas. Most of these pollutants settle on the outdoors and eventually become part of the outdoor dust. These will have negative long-term repercussions on ecosystems and human health. In this research, energy dispersive X-ray fluorescence (EDXRF) spectrometry analytical method was used to assess the pollution characteristics of the eight heavy metals (HMs): Mn, Cu, As, Hg, Ni, Cr, Zn, and Pb in the East Mediterranean Sea area. The concentration of As, Mn, Cr, Cu, Hg, Ni, Pb, and Zn analyzed in outdoor dust samples varied from 0.94 to 19.52 mg kg-1, 190.08 to 1019.7 mg kg-1, 20.46 to 45.9 mg kg-1, 19.5 to 62.56 mg kg-1, 0.01 to 0.93 mg kg-1, 10.48 to 40.64 mg kg-1, 12. 6 to 36.1 mg kg-1, and 48.96 to 112.41mg kg-1, respectively. HMs have been detected in the outdoor dust samples analyzed in the study, and, as a result, mean concentrations followed the order Mn > Zn > Cu > Cr > Ni > Pb > As > Hg, respectively. The ecological risk was observed at various contamination levels, with As and Hg pollution being the most severe. The highest hazard quotient (HQ) for adults and children was determined as a result of As and Cr, respectively. According to the US-EPA health risk threshold, the cancer risk in the study area is negligible.

Radioactivity concentration levels and potential radiotoxicity risk assessment of aquatic superfoods case study of algae supplements

It has been found that algae have a variety of health benefits, although investigations showed that they contain radiotoxic elements, including 226Ra, 232Th, 40K, and 137Cs, which may affect human health. This study is connected to activity concentration measurements of the above radionuclides in the algae supplements available in the Middle East markets. The annual effective radiation doses of measured radionuclides in analyzed algal supplements have been calculated. The highest values of annual effective doses have been estimated for 226Ra in Ecklonia (13.39 μSv/y) and for 232Th in Red Marine Algae (11.80 μSv/y), both from South Korea. In algal "superfoods", the effective dose of 137Cs is not significantly affected by the Fukushima Nuclear Power Plant. Based on these results, it can be concluded that the activity levels of radionuclides are low, the naturally occurring radionuclides provide the most effective doses, and algae supplements can be considered safe.

Elemental composition and metal pollution in Egyptian Red Sea mangrove sediments: Characterization and origin

The present work was conducted to characterize the mangrove sediments along the Egyptian Red Sea in terms of elemental composition and to assess the extent of pollution and its sources. A total of 26 samples of mangrove sediments were collected from three different areas: Sharm El Madfea, Sowmaa Mangrove and Abu Fasi. The samples were analyzed using the inductively coupled plasma - mass spectrometry ICP-MS and atomic-emission spectrometry ICP-AES. Mass fractions of a total of 58 major and trace elements were determined in the mangrove samples. Univariate and multivariate statistical analyses were performed to determine the origin of trace and major elements in the mangrove sediments. The normalized values show that the elements above the background can be indicated in descending order as follows: P > Cd > Sr > Ca > U > Se > As > Sn > Cu > Sb > Pb > Mo > Ag. Several pollution indices were also calculated. Principal component analysis revealed three clusters of the studied sediment samples. The analysis of the ratio indicators shows that the origin of the sediments mostly falls near continental island arcs (CIA). The pollution indices show remarkable pollution levels and enriched elements. The data obtained can serve as baseline data for the sediments of the mangrove environment and can be used to study possible changes in the future.

Appraisal of heavy metal contents, spatial-temporal variation, toxic metal pollution, and health risk in water and sediment of Uluabat Lake (Ramsar Site, Turkey)

Uluabat Lake holds a significant status as one of our country's essential Ramsar areas. Nevertheless, the lake faces considerable pressure from environmental pollutants. This study employed GIS-based index methods to examine the heavy metal pollution and water quality in Uluabat Lake. To achieve this, sediment and water samples were collected from 19 different locations during various seasons. The concentrations of As, Ni, Cr, Zn, Cu, Cd, Pb, Hg, Al, Fe, and Mn in these samples were analyzed. The average contents of the investigated heavy metals in the lake waters were found to be in the following order: Al > Fe > Mn > As > Zn > Ni > Pb > Cu > Cr > Hg > Cd. The As content in the lake waters exceeded the limit value of 10 μg/L, as defined by TS-266 (2005) and WHO (2017) guidelines. Consequently, the lake waters were deemed unsuitable for drinking. The health risk assessments revealed that consuming the lake waters could lead to both carcinogenic and non-carcinogenic health problems. However, all other metal concentrations were measured below the specified limit values. Based on index calculations, the heavy metal pollution index value indicated that the lake water samples were suitable for drinking water use. Additionally, all samples fell into the "low pollution" category according to the heavy metal evaluation index, and degree of contamination values. However, geoaccumulation index values indicated that As was moderately contaminated. Moreover, enrichment factors of As, Cr, Ni, Pb, and Cd exhibited significant enrichment in lake sediments, with pollution load index values of all sediment samples indicating the impact of anthropogenic pollutants and a decline in sediment quality. Considering all the obtained results together, it can be concluded that environmental pollutants, especially heavy metal pollution, primarily enter the lake water through stream transports, leading to pollution in Uluabat Lake.

Dolphin-shaped island: Exploring the natural resources and radiological hazards of Wadi El Gemal Island

The objective of this study is to assess the natural resources and radiological risks of Wadi El Gemal Island by examining its topography, mineralogy, geochemistry, and radioactive distributions. This island, which is situated at the outlet of Wadi El Gemal in Egypt's southeastern Desert, has a unique shape resembling a dolphin based on Landsat imagery. It's a part of the Wadi El Gemal-Hamata Protectorate and is notable for its diverse environmental, geological, economic, and archeological features, including recent reefs, sandy deposits, Quaternary carbonate sediments, and mangroves. The main natural resources on the island are fauna, mangrove forests, and flora. Samples collected from the island were analyzed using a NaI detector to measure the concentrations of radionuclides such as 238U, 232Th, 226Ra, and 40K, which were found to be within acceptable levels according to UNSCAR guidelines. The radionuclide 238U, 232Th, 226Ra, and 40K activity concentrations of the collected samples were 32.55 ± 9, 12.63 ± 4, 12.49 ± 4, and 325 ± 34 Bq/kg, respectively. Regarding radiological hazard indices, the values of absorbed gamma dose rate (36.06 ± 5.42 nGy/h), radium equivalent activity (73.88 ± 14.4 Bq/kg), annual effective dose indoor (0.18 ± 0.03 mSv/y) and outdoor (0.04 ± 0.01 mSv/y), internal (0.29 ± 0.05) and external (0.2 ± 0.03) indices, and excess lifetime cancer index (0.15 ± 0.05 × 10-3).This is suggest that there is no significant risk associated with these sediments.

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

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.

Advances in the management of radioactive wastes and radionuclide contamination in environmental compartments: a review

Several anthropogenic activities produce radioactive materials into the environment. According to reports, exposure to high concentrations of radioactive elements such as potassium (⁴⁰K), uranium (²³⁸U and ²³⁵U), and thorium (²³²Th) poses serious health concerns. The scarcity of reviews addressing the occurrence/sources, distribution, and remedial solutions of radioactive contamination in the ecosystems has fueled data collection for this bibliometric survey. In rivers and potable water, reports show that several parts of Europe and Asia have recorded radionuclide concentrations much higher than the permissible level of 1 Bq/L. According to various investigations, activity concentrations of gamma-emitting radioactive elements discovered in soils are higher than the global average crustal values, especially around mining activities. Adsorption technique is the most prevalent remedial method for decontaminating radiochemically polluted sites. However, there is a need to investigate integrated approaches/combination techniques. Although complete radionuclide decontamination utilizing the various technologies is feasible, future research should focus on cost-effectiveness, waste minimization, sustainability, and rapid radionuclide decontamination. Radioactive materials can be harnessed as fuel for nuclear power generation to meet worldwide energy demand. However, proper infrastructure must be put in place to prevent catastrophic disasters.

Chronology of trace elements and radionuclides using sediment cores in Golden Horn Estuary, Sea of Marmara

Trace elements and radionuclides are substantial pollutants in marine environment since they are non-biodegradable and can be harmful even in minute concentrations. The Golden Horn estuary, where is an inlet of Bosphorus and two creeks, has been seriously polluted by untreated municipal and industrial dischargers for several decades. Since 1998, a large restoration and rehabilitation efforts have been undertaken in the estuary to mitigate the pollution. In the present study, four sediment cores were taken from the Golden Horn estuary to assess the historical accumulation of trace elements and radionuclides. Radiometric dating was implemented by ²¹⁰Pb and ¹³⁷Cs radionuclides and CRS model. Sedimentation rates were calculated in the range of 0.92-0.97 cm yr^-1 in the estuary. The distribution of radionuclides (⁴⁰K, ²²⁶Ra, and ²²⁸Ra) indicated some slight variations which ascribes to the geological characteristics of sediment along the cores. The concentrations of the anthropogenic elements were relatively higher in the intensive industrialization period. Their concentrations reduced in the latest 15-20 years thanks to the large-scale rehabilitation project in the estuary. The pollution indices, namely EF, Igeo, CF, and PLI showed that the concentrations of Cd, Cr, Cu, Pb, Sb, and Sn were above the world averages. Our results provide an insight on the long-term accumulation trends of trace element in the Golden Horn, which revealed that the estuary remains moderately polluted. We suggest that preventive countermeasures are much more important than post pollution remediation in the case of metallic pollution in the estuaries.

Natural radioactivity and its radiological implications from soils and rocks in Jaintiapur area, North-east Bangladesh

Natural radioactivity concentrations in recent alluvial soils from swampy areas and Tertiary rocks from Jaintiapur were measured using gamma-ray spectrometer equipped with HPGe detector. The average radioactivity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K were 47 ± 6, 64 ± 5 and 762 ± 40 Bqkg⁻¹ in soils, whereas, 25 ± 2, 37 ± 4 and 884 ± 41 Bqkg⁻¹ in rock samples, respectively. Average radioactivity concentrations of studied soil and rock samples exceeded the world average except ²²⁶Ra for rocks. Radio-elemental ratios suggest that an oxic depositional environment with low uranium and high thorium content. Regarding radiological hazard indices, radium equivalent activities (Ra_eq), external hazard index (H_ex) and internal hazard index (H_in) was found to be below the world permissible limits. Whereas, absorbed dose rate (D), and annual effective dose equivalent (AEDE) averages exceeded the world admissible values. Statistical studies show that radioactivity for ²²⁶Ra and ²³²Th linked to a source enriched in radioactive minerals and ⁴⁰K related to a different sources high in K enriched minerals.

Application of RESRAD and ERICA tools to estimate dose and cancer risk for artisanal gold mining in Nigeria

Despite the fact that disruption of the environment through mining of minerals poses severe radiological hazards, there is a dearth of radiological information from gold mining sites in Nigeria. In this study, state-of- the-art computational tools - RESRAD ONSITE, RESRAD OFFSITE and ERICA were applied to a typical representative artisanal goldmining area for a more comprehensive evaluation of radiological risks associated with artisanal gold mining in Nigeria. The estimated doses received by an offsite receptor is within the radiation basic safety limit, while for onsite receptor it is greater than the basic radiation safety limit. It was observed that onsite dwellers of the artisanal goldmining areas may suffer high cancer burden when compared with the US EPA acceptable levels. For non-human biota, the hazard quotient was greater than unity and the total dose rate per organism was greater than the screening dose rate of 10μGy h^-1. It was observed that ²³²Th and ²²⁶Ra were the main contributors to the total dose and the pathways that contributed most to the dose were; external exposure (via direct and airborne radiation from soil and Radon) as well as water independent plant, meat and milk consumption. Therefore, monitoring food production will lead to an informed decision making and risk communication towards sustainable mining will contribute in minimizing the level of the anticipated risks as low as reasonably achievable.

Distribution of Radionuclides and Radiological Health Assessment in Seih-Sidri Area, Southwestern Sinai

The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (H_ex, H_in), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Ra_eq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core ²³²Th/²³⁸U mass fractions were determined from the obtained values of ²³⁸U, ²³²Th and ⁴⁰K for the examined rocks of Seih-Sidri area. The average ²³⁸U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one's radiological health.

An Extended Investigation of High-Level Natural Radioactivity and Geochemistry of Neoproterozoic Dokhan Volcanics: A Case Study of Wadi Gebeiy, Southwestern Sinai, Egypt

High-level natural radioactivity, geochemical, geological, and radiological hazard assessment of the poorly investigated Wadi Gebeiy Dokhan volcanics rocks are discussed. Wadi Gebeiy Dokhan volcanics are located in Southwestern Sinai, Egypt, covering an area of ~1.3 km2. Dokhan volcanics rocks are represented by porphyritic dacite. Geochemically, they have medium-k characters and originate from calc-alkaline magma within a volcanics arc environment. Along the fault plane striking NNE-SSW, and at its intersection with the NW-SE fault plane, altered Dokhan volcanics occur with high radioactive anomalies. Radiological parameters (absorbed dose rate, radium equivalent, activity annual effective dose, external and internal hazard indices) are used to evaluate their suitability as an ornamental stone. Except for the absorbed dose rate, all the radiological hazard indices show that unaltered Dokhan volcanics can be used as an ornamental stone. Controversially, the applied radiological indices reveal that altered Dokhan volcanics have a higher content than the recommended values of UNSCEAR, reflecting their risk on human organs.

An In-Depth Examination of the Natural Radiation and Radioactive Dangers Associated with Regularly Used Medicinal Herbs

The specific activity of U-238 and Th-232, as well as K-40 radionuclides, in twenty-nine investigated medicinal herbs used in Egypt has been measured using a high-purity germanium (HP Ge) detector. The measured values ranged from the BDL to 20.71 ± 1.52 with a mean of 7.25 ± 0.54 (Bq kg−1) for uranium-238, from the BDL to 29.35 ± 1.33 with a mean of 7.78 ± 0.633 (Bq kg−1) for thorium-232, and from 172 ± 5.85 to 1181.2 ± 25.5 with a mean of 471.4 ± 11.33 (Bq kg−1) for potassium-40. Individual herbs with the highest activity levels were found to be 20.71 ± 1.52 (Bq kg−1) for uranium-238 (H4, Thyme herb), 29.35 ± 1.33 (Bq kg−1) for thorium-232 (H20, Cinnamon), and 1181.2 ± 25.5 (Bq kg−1) for potassium-40 (H24, Worm-wood). (AACED) Ingestion-related effective doses over the course of a year of uranium-238 and thorium-232, as well as potassium-40 estimated from measured activity concentrations, are 0.002304 ± 0.00009 (minimum), 0.50869 ± 0.0002 (maximum), and 0.0373 ± 0.0004 (average)(mSv/yr). Radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), absorbed gamma dose rate (Doutdoor, Dindoor), gamma representative level index (I), annual effective dose (AEDtotal), external and internal hazard index (Hex, Hin), and excess lifetime cancer risk were determined in medicinal plants (ELCR). The radiological hazards assessment revealed that the investigated plant species have natural radioactivity levels that are well within the internationally recommended limit. This is the first time that the natural radioactivity of therapeutic plants has been measured in Egypt. In addition, no artificial radionuclide (for example, 137Cs) was discovered in any of the samples. Therefore, the current findings are intended to serve as the foundation for establishing a standard safety and guideline for using these therapeutic plants in Egypt.

Statistical analysis on the radiological assessment and geochemical studies of granite rocks in the north of Um Taghir area, Eastern Desert, Egypt

Granite rocks are currently one of the foremost raw materials that can be used for various economic purposes such as ornamentation and building materials, because they do not possess radioactive concentrations and have good physical and mechanical properties. The granite rocks of north Um Taghir are connected to neoproterozoic rocks and integrated to the north Arabian-Nubian Shield (ANS), which lies in Northeast Africa. Inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence analysis, concurrent to some statistical analysis, have been carried for major oxides and some trace elements to extract much fundamental information by following certain mathematical methods. The exposed granite rock units in north Um Taghir are classified into four rock units represented by tonalite, granodiorite, monzogranite, and alkali-feldspar granite which are cut by different types of dikes. The magma of tonalite and granodiorite is low-to-medium K calc-alkaline affinity, while the magma of monzogranite and alkali-feldspar granite is medium-to-high K calc-alkaline affinity, and of metaluminous to peraluminous nature. Granite rocks show a slightly depletion of fractionated patterns from light rare earth elements (LREEs) to heavy rare earth elements (HREEs) with slightly positive to negative Eu anomalies from tonalite to monzogranite and alkali-feldspar granites. The statistical criteria have been achieved to explore the significant differences of radiological hazard parameters among samples. It is obvious that there is no homogeneity among samples; furthermore, in Kruskal–Wallis test, Mann–Whitney test, and Pearson correlation coefficient, it can be noticed that there are significant differences between each pair of samples: tonalite, monzogranite; tonalite, alkali-feldspar granite; granodiorite, monzogranite; and granodiorite, alkali-feldspar granite. There is a strong direct relationship among granodiorite and both tonalite and alkali-feldspar granite, and among alkali-feldspar granite and tonalite and granodiorite. There is a strong inverse relationship among monzogranite and tonalite, granodiorite, and alkali-feldspar granite. As stated by all results, it can be mentioned that the granite rocks have a worthy result of mechanical and physical properties. So that they can be used for various economic purposes.

Analysis of the Radiological, Mineralogical and Long-Term Sustainability of Several Commercial Aswan Granites Used as Building Materials

The widespread usage of granite in the building sector motivated us to conduct this research and examine the material’s sustainability in terms of the investigated characteristics. The purpose of this paper is to discuss the statistical analysis results for the mineralogical impact on radiological hazards indices, such as the equivalent of radium, absorbed gamma dose rate, annual effective dose, internal and external hazard indices, as well as the gamma-ray index, that were calculated to estimate the environmental risks associated with these granites used as building materials, to protect the public from excessive radioactivity exposure. We focused primarily on statistical significance at a 95% confidence level. We employed a non-parametric test (Kruskal–Wallis Test) rather than a one-way ANOVA, to determine the statistical significance of the samples due to the lack of homogeneity or normality among them. To assess the difference between the samples, we used the Mann–Whitney Test on each pair of samples. Additionally, Pearson correlation coefficients for all the mineralogical results are computed. The presence of K-rich minerals (Kefeldspars, biotite) and accessories such as uranophane, uranothorite, allanite, xenotime, fergusonite, aeschynite, zircon, cassiterite, apatite, and sphene, which are mostly found in granitic rocks, determines the level of natural radioactivity of the investigated granites. Most of the rock samples analyzed have indicators of radioactive dangers that are within the acceptable level range, indicating that they are suitable for use as building materials. On the other hand, some samples have environmental criteria that are higher than international standards, indicating that they are unsuitable for use as construction materials.

Petrology and geochemistry of multiphase post-granitic dikes: A case study from the Gabal Serbal area, Southwestern Sinai, Egypt

Variable single and/or swarms of post-granitic dikes are widespread at Gabal Serbal, Southwestern Sinai, Egypt. The present article aims to identify and discriminate these multiphase dikes through detailed geological, petrographical, and geochemical examinations. These dikes are classified into two subphases: (1) acidic dikes (porphyritic dacite, microgranite, granophyre, and alkaline granophyre dikes); and (2) basic dikes (basalt and dolerite dikes). They range from vertical or steeply inclined bodies, 0.5–15 m wide, pink to black color, and NE–SW to N–S directions. Acidic dikes with different mineralogical constituents have medium to high k-characters, originating from calc-alkaline magma and extruded in a volcanic arc environment. In contrast, basic dikes have medium k-characters, originating from tholeiitic magma and developing within a plate environment. Basic dikes are enriched with opaque minerals, where the basaltic dike contains iron oxides (magnetite and hematite), such as apatite in addition to copper minerals. Dolerite dike comprises magnetite, titanomagnetite, and pyrite.

Assessing the Radiological Risks Associated with High Natural Radioactivity of Microgranitic Rocks: A Case Study in a Northeastern Desert of Egypt

This study aimed to evaluate the radiological hazards of uranium (²³⁸U), thorium (²³²Th), and potassium (⁴⁰K) in microgranitic rocks from the southeastern part of Wadi Baroud, a northeastern desert of Egypt. The activity concentrations of the measured radionuclides were determined by using a gamma-ray spectrometer (NaI-Tl-activated detector). The mean (²³⁸U), (²³²Th), and (⁴⁰K) concentrations in the studied rocks were found to be 3680.3, 3635.2, and 822.76 Bq/kg, respectively. The contents in these rocks were elevated, reaching up to 6.3 wt%. This indicated the alkaline nature of these rocks. The high ratios of Th/U in the mineralized rocks could be related to late magmatic mineralization, suggesting the ascent of late magmatic fluids through weak planes such as faults and the contact of these rocks with older granites. The present data were higher than those of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) guideline limits. All the radiological hazard results indicated high human health risks. This confirmed that this area is not radiologically safe, and care must be taken when working in this area. This study showed that the area under investigation had high U content suitable for uranium extraction that could be used in the nuclear fuel cycle.

Radiological risk assessment of natural radionuclides in the marine ecosystem of the Northwest Mediterranean Sea

Purpose: This study aimed to assess the radiological risk of natural radionuclides (²²⁶Ra, ²³²Th, and ⁴⁰K) to marine ecosystem biota. Materials and Methods: The study site in this was the Mediterranean Sea, Cyprus. With the use of the RESRAD-BIOTA (RESidual RADioactivity BIOTA) code, the tissue concentration, external and internal dose rate of aquatic animals and riparian animals were estimated. Results: The total tissue concentrations of the aquatic animals and riparian animals were simulated at 1.14 × 10⁶ Bq/kg (water media) to 0 Bq/kg (sediment media), and 1.33 × 10⁶ Bq/kg (water media) to 9.79 × 10¹ Bq/kg (sediment media), respectively. The total dose rate for aquatic animals and riparian animals were ranged from 1.94 × 10^-2 to 0 Gray per day (Gy/d) and 1.46 × 10^-2 to 7.40 × 10^-7 Gy/d, respectively. Conclusions: Based on the risk assessment of this study, there is no significant impact due to organisms' exposure to natural radioactivity. Although, further consideration of the exposure levels is required due to the potential effects of protracted low-level ionizing radiation.

An extended assessment of natural radioactivity in the sediments of the mid-region of the Egyptian Red Sea coast

In this study, nearly 84 marine sediment samples were collected from twelve points in four cities (Quseir, Safaga, Hurghada, and Ras Gharib) along the Egyptian Red Sea sectors. The collected samples were extensively examined to estimate the natural radioactivity level. The obtained results were compared to the reported ranges from other locations in different countries. Hazardous radiation parameters such as radium equivalent, annual dose, and external hazards were estimated and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended levels. The values were recorded in the first natural radioactivity database of coastal sediments from Egyptian Red Sea cities. The dose rate for certain organs was evaluated. The results showed that Red Sea beach sediments are safe in terms of natural radioactivity. It can be concluded that they do not pose a risk to tourists going to the beaches for recreation or to sailors and fishers involved in economic activities along the Egyptian Red Sea coast.

An overview of brine management: Emerging desalination technologies, life cycle assessment, and metal recovery methodologies

This study examines which management methods are the most recent and advanced in managing rejected brine generated from desalination plants. It also provides up-to-date information regarding the most adequate technologies that generate a minimum quantity of rejected brine via the use of minimization techniques and analyzes the method of direct disposal that has lately received noticeable improvements. It further discusses the reuse of discarded brine to recover valuable goods and sequestration of carbon dioxide. Sustainability is an important parameter that needs consideration to achieve uninterrupted operation of the discarded brine management to achieve the least environmental, social, and economic aftermath. To properly deal with any environmental issues related to brine disposal, different methods are implemented so that, in the end, higher water recovery is achievable from the desalination processes, namely brine minimization and rejection technologies (pressure retarded osmosis, microbial desalination cell technology), membrane-based technologies (vibratory shear enhanced processing, forward osmosis, electrodialysis, electrodialysis reverse, and electrodialysis metathesis, pervaporation method, thermal-based technologies (wind-aided intensified evaporation, brine concentrators, ohmic evaporator, membrane distillation, multi-stage flash distillation. This review also critically examined the two conventional approaches commonly used in life cycle assessment (LCA), when evaluating the ecotoxic effect of discarded brine. It intends to discuss the currently available methods and propose an improved method for evaluating the toxicity potential of brine on the aquatic ecosystem originated from seawater desalination plants. The Group-by-Group method takes into consideration the demerits of the two methods of the traditional method of LCA or chemical-specific approach as it provides a more holistic coverage for complicated brine to be disposed of. Recently, attention has been focused on recovering valuable metals from the discharged concentrated brine waste. Certainly, attaining marketable products from the discharged concentrated brine would offer an economic benefit and reducing the whole desalination costs. Ion imprinting polymers have potential applications in metal recovery from brine. Finding selective, more efficient, and less expensive imprinted polymers for extraction/pre-concentration of valuable ions is a vital and challenging task. Lastly, the brine should be seen as a resource and not as a waste to attain sustainability in its management approaches. Hybrid processes would be highly recommended to get the absolute transformation of the discarded brine from desalination processes to more valuable constituents.

The presence of radioactive heavy minerals in prospecting trenches and concomitant occupational exposure

Uranium, perhaps the most strategically important component of heavy minerals, finds particular significance in the nuclear industry. In prospecting trenches, the radioactivity of 238U and 232Th provides a good signature of the presence of heavy minerals. In the work herein, the activity concentrations of several key primordial radionuclides (238U, 232Th, and 40K) were measured in prospecting trenches (each of the latter being of approximately the same geometry and physical situation). All of these are located in the Seila area of the South Eastern desert of Egypt. A recently introduced industry standard, the portable hand-held RS-230 BGO gamma-ray spectrometer (1024 channels) was employed in the study. Based on the measured data, the trenches were classified as either non-regulated (U activity less than 1000 Bq kg-1) or regulated (with 238U activity more than 1000 Bq kg-1). Several radiological hazard parameters were calculated, statistical analysis also being performed to examine correlations between the origins of the radionuclides and their influence on the calculated values. While the radioactivity and hazard parameters exceed United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) guided limits, the mean annual effective doses of 0.49 and 1.4 mSv y-1 in non-regulated and regulated trenches respectively remain well below the International Commission on Radiological Protection (ICRP) recommended 20 mSv/y maximum occupational limit. This investigation reveals that the studied area contains high uranium content, suitable for extraction of U-minerals for use in the nuclear fuel cycle.

A Review of Heavy Metals in Coastal Surface Sediments from the Red Sea: Health-Ecological Risk Assessments

The heavy metal (HM) pollution in sediment is of serious concern, particularly in the Red Sea environment. This study aimed to review and compile data on the concentrations of four HMs (Cd, Cu, Pb, and Zn) in the coastal surface sediments from the Red Sea, mainly from Saudi Arabia, Egypt, and Yemen, published in the literature from 1992 to 2021. The coastal sediments included those from mangrove, estuaries, and intertidal ecosystems. It was found that the mean values of Cd, Cu, Pb, and Zn in coastal Red Sea sediments were elevated and localized in high human activity sites in comparison to the earth upper continental crust and to reference values for marine sediments. From the potential ecological risk index (PERI) aspect, 32 reports (47.1%) were categorized as ‘considerable ecological risk’ and 23 reports (33.8%) as ‘very high ecological risk’. From the human health risk assessment (HHRA) aspect, the non-carcinogenic risk (NCR) values (HI values < 1.0) of Cd, Cu, Pb, and Zn represented no NCR for the ingestion and the dermal contact routes for sediments from the Red Sea countries. The reassessment of the HM data cited in the literature allowed integrative and accurate comparisons of the PERI and HHRA data, which would be useful in the management and sustainable development of the Red Sea area, besides being a helpful database for future use. This warrants extensive and continuous monitoring studies to understand the current and the projected HM pollution situation and to propose possible protective and conservative measures in the future for the resource-rich Red Sea ecosystem.

A review of major and trace elements in Nile River and Western Red Sea sediments: An approach of geochemistry, pollution, and associated hazards

The present review was conducted to highlight the major and trace elemental composition in surface sediments from the Nile River and Egyptian Red Sea coastal areas in terms of provenance, concentrations, pollution indices, and health hazards. Health hazard due to the exposure to selected elements via inhalation, ingestion, and dermal contact was calculated. The samples were subjected to neutron activation analysis. Bivariate and multivariate statistical analysis was employed. Significant amounts of V, Cr, and Zr are observed in Nile sediments. Whereas, considerable concentrations of Br and Ca were found in marine sediments. The concentrations of the other elements are in line with the corresponding values in upper continental crust. The outcomes of the pollution indices show some localized polluted sites (Helwan, Cairo, and Delta) in Nile sediments. Likewise, in Abu Ghusun area in marine ones. Overall, the hazard index of the investigated elements in the Nile and marine sediments for both studied age criteria is higher than the tolerable values (1 × 10^-6 - 1 × 10^-4).

Models for predicting the transport of radionuclides in the Red Sea

Two radionuclide transport models for the Red Sea are described: a Lagrangian model to deal with emergency situations and a Eulerian model better suited to longer term simulations, as for instance required in case of chronic radionuclide releases. Baroclinic circulation is obtained for both transport models from HYCOM ocean model. The Lagrangian model also includes tides, which are obtained from a standard tidal model customized to the Red Sea, and currents induced by local winds. Both models describe exchanges of radionuclides between water and sediments. A number of simulations were carried out to illustrate capabilities of the models. Additionally, flushing times over the Red Sea were evaluated with the Eulerian model, as another example of model use.

Investigations on chemical composition and natural radioactivity levels from salt water and peloid used in pelotherapy from the Techirghiol Lake, Romania

The work presents the historical evolution, objectives, goals, concepts, chemical and radiometric methods, results and conclusions for salt waters and natural peloids used in pelotherapy. This study assesses chemical composition, natural radioactivity concentrations and the radiological hazard in peloid and salt water samples, from ten places in the Techirghiol Lake from Romania. Pelotherapy is a very important procedure, and thus, the materials used for this purpose must be well characterized to guaranty safety use. Concentrations of elements such as Sr, Ba, Mn, Fe, Sb, Zn, Cu, Pb, Ti, Ni, Cr, As have been measured using ICP-OES analytical technique. The natural radionuclides such as ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K have been determined by gamma-ray spectrometry. The average activity concentrations were of 0.48 ± 0.10 Bq/kg for ²³⁸U, 0.60 ± 0.10 Bq/kg for ²²⁶Ra, 0.30 ± 0.08 Bq/kg for ²³²Th and 17.5 ± 1.3 Bq/kg for ⁴⁰K for salt water samples. Also, the mean activity concentrations for peloids were: 5.70 ± 1.00 Bq/kg for ²³⁸U, 6.85 ± 1.60 Bq/kg for ²³²Th, 15.3 ± 3.7 Bq/kg for ²²⁶Ra and 95.8 ± 5.5 Bq/kg for ⁴⁰K. The results from this study contribute to the identification of possible contaminants in the salt water and peloid, and their association with the potential ecological and human health risk. In this context, of using salt water and peloid in a relatively long treatment period, several radiological indices have been calculated, to determine if the radionuclide's content can be also harmful to human health. The assessment indicates that humans are not exposed to concentrations of metal contaminants higher than the international recommended values.

Seasonal variation of nutrient salts and heavy metals in mangrove (Avicennia marina) environment, Red Sea, Egypt

In the Egyptian Red Sea coast, nutrient salts, major ions, and heavy metals ion concentrations were examined in mangroves and the results were compared to respective concentrations in a reference area. Water samples were collected during the four seasons of 2012 from three different mangrove regions, Safaga, Abo Gheson, and El Quseer, besides, a mangrove free region, Marsa Alam. A temporal variation in the chemical composition of seawater of the mangrove and reference regions was recorded. Phosphorous and nitrogen forms were measured and calculated. Fe, Mn, Cu, Zn, Ni, Cr, Cd, and Pb ions were measured in water samples. Redfield nitrogen to phosphorous ratio explained the oligotrophic nature of the Red Sea. Ca and Mg ions besides total alkalinity showed negligible variations. The relatively greater concentration values of ammonium, 242.11 μg/l, dissolved inorganic nitrogen, 315.55 μg/l, and oxidizable organic matter, 0.4 mg-O₂/l, may be caused by the impact of mangroves. Seawater contamination by heavy metals was assessed, using the metal index, in the mangrove regions which, compared to the reference region, were highly contaminated. Analysis of variance showed no significant variation among mangrove stations. Principal component analysis suggested that El Quseer and Safaga, mangrove regions, were contaminated by metal ions. Safaga possessed the highest concentration of Cd and Zn ions, while the highest concentrations of Mn, Cu, Ni, and Pb ions were observed at El Quseer. This may be attributed to industrial and shipping activities. It is concluded that the mangrove ecosystem along the Red Sea highly affects marine environment.