Microplastics (MPs) are widely distributed in the environment. MP pollution has been found in the environment globally, which directly threatens human health. It is of great importance to study the influencing factors and mechanism of MP migration in the vadose zone to evaluate its distribution and environmental risk accurately. Through a literature review, the source, migration, and transformation of MPs in the vadose zone were summarized, and the influencing factors of MP migration in the vadose zone were systematically expounded. The mechanism of MP migration was analyzed, and future research was suggested. The factors affecting the migration of MPs can be divided into chemical, physical, and biological categories. At present, research on the migration of MPs in the vadose zone is in its infancy. In a further study, the migration of MPs at the field scale, the synergistic migration and transformation of MPs with other pollutants and the mutual feedback mechanism, and the use of the properties and biological functions of the vadose zone to study the role and mechanism of MPs in global carbon neutralization are worthy of attention.

Gold-sulfide mineralization in the Abu Zawal (Fatira) mine area, North Eastern Desert of Egypt, is related to porphyritic felsite dikes and elongate silicification zones in granitic rocks. These felsite dikes and the host granitic rocks exhibit major and trace element geochemical features typical of calc-alkaline and metaluminous I-type granites, likely originated in a late-orogenic setting. Their geochemical characteristics along with their fractionated LREE relative to HREE patterns imply either formation in a subduction-related environment or generation from subduction-modified source materials. Partial melting of subduction-metasomatized lower crustal rocks during extension following the lithospheric thickening may account for the production of such fertile, high Sr/Y and La/Yb magmas. In the Abu Zawal (Fatira) area, NE-trending altered felsite dikes, hydrothermal breccias, quartz enclaves, and wall-rock replacements are characterized by disseminations of chalcopyrite, pyrite, and rare gold. Alteration mineralogy, dominated by sericite, drusy quartz, kaolinite, calcite, and specular hematite, combined with the available fluid inclusion data suggests moderate to low temperature and near neutral pH conditions. The geochemical data of the altered wallrocks and mass balance calculations indicate significant mass losses in the altered rocks consistent with fluid/wallrock ratios higher than unity and near neutral pH conditions. Considering that the silica-rich host rocks, hydrothermal alteration, and sulfide-bearing hydrothermal quartz breccia in Fatira mine area were intuitively related to sulfur-saturated, oxidized felsic magmatism and associated hydrothermal systems, they are most likely linked to the post-subduction felsite porphyries (post-Hammamat felsites ~ 607 Ma), or pertaining to the late phases of the subaerial high-K calc-alkaline volcanics (Dokhan Volcanics ≤ 620 Ma).

In order to study the occurrence form, vertical migration and transformation and the potential ecological risk of Hg in the disjointed hyporheic zone in the gold mining area is investigated. Through field investigation, in-situ test, and test analysis, the results show that: (1) the form of mercury in the original stratum where the river water-groundwater hydraulic connection is disconnected is mainly in the residual state, accounting for 77.78% of the total mercury; (2) after the water content increases or the water level changes, the various forms of occurrence in the soil surface layer decrease, and the residual state is still the main form; the main forms of mercury in the sand and pebble layer are diversified, including the residual state, strong organic state and humic acid state; (3) the mercury content in the subsurface zone in winter is higher than that in summer; (4) although the mercury content in groundwater has not been detected, the potential ecological risk of mercury in the disjointed Hyporheic zone near the river in the study area is much higher than the extreme ecological hazard threshold, which has a value of 320. The risk of groundwater pollution caused by mercury during the long-term runoff of the river is higher than that during the flood period. Therefore, relevant departments need to rectify the river as soon as possible, from the source to reduce the ecological risk of heavy metals to groundwater. The results will provide a scientific basis for groundwater control.

Fluoride (F) is an essential element of drinking water for human health, especially for bone development and enamel creation. However, if the fluoride content in drinking water is higher than 1.5 mg/L or lower than 0.5 mg/L, it will cause endemic diseases, such as dental fluorosis. There are two main hydrogeological characteristics: the properties of the water-bearing rocks and groundwater conditions controlled the groundwater in guide basin. The geothermal water can be divided into fracture convection and sedimentary basin geothermal water according to its geological environment and heat transfer mode. Inductively coupled plasma spectrometry is a significant tool for groundwater quality analysis. The geochemical factors of fluoride enrichment in confined geothermal water mainly include pH, ion exchange, and mineral saturation. Both groundwater samples are slightly alkaline, while the phreatic water and surface water record pH values of 8.5, 7.78, and 7.8, respectively. The salinity of groundwater water is not high, but for confined geothermal water, phreatic water, and surface water measures 706.0, 430.1 and 285.9 mg/L respectively. The higher the pH of groundwater, the more beneficial it is to the enrichment of fluoride. In contrast, the main cations in phreatic water and surface water are calcium ions and magnesium ions. The anions in groundwater and surface water mainly include SO₄²⁻ and HCO₃⁻, followed by Cl⁻, indicating that the groundwater and surface water here is mainly leaching. Fluoride was shown to be positively correlated with sodium and bicarbonate. Moreover, the results indicate that F⁻ enrichment is usually associated with high HCO₃⁻ and Na⁺ concentrations in water, while a high Ca²⁺ concentration tends to lower the F⁻ concentration in water. This means that the ion exchange between calcium ions and sodium ions may lead to fluoride enrichment in natural water. As mentioned above, high-sodium and low-calcium water are favorable for fluoride enrichment. Moreover, saturation indices of fluorite, gypsum, dolomite, and calcite, as well as the saturation index of fluorite, represent a vital method to understand the fluoride enrichment. According to this study, fluoride as a pollutant poses great risks to human health overall, whether lower than or higher than the drinking water limit. Children face higher health risks than adults caused by confined geothermal water drinking intake. This study suggests that groundwater treatment should be conducted to reduce fluoride concentration in drinking water. It is suggested that when confined geothermal water is used as drinking water, it should be mixed with phreatic water and surface water in a certain proportion to make the fluoride in groundwater reach the range of safe drinking water.

Gold deposits and occurrences are spread over a large number of sites which covered by Precambrian the basement rocks in the Eastern Desert of Egypt, and the gold exploration and mining activities had been districted since ancient times. The ancient Egyptians extracted gold from quartz veins of various dimensions in open pits and underground workings. Consequently, gold production in Egypt seems to have started as early as the predynastic times (about 6000 BCE) from Pre-and Early Dynastic times to Early Arab Period. In the modern days, Egyptian mineral resource authority announced many big international bid-rounds for Gold Exploration and associated minerals was launched to open the minerals sector to foreign investment in the mining industry. Many studies have been achieved to classify the gold deposits in Egypt based on various characteristics such as the nature, occurrences, type of host rock, tectonic setting, metal association, fluid inclusion, and the tectonic environment of mineralization. Gold deposit in Egypt still need more geological and mining studies to understand the gold system types, additionally, to get answers regarding to source, transportation, traps, and host rocks, as well as the whole challenges in mining sectors.