Eight heavy metals were measured seasonally in the sediment of Lake Nasser during 2013. 27 sites were chosen through 9 sectors across the main channel of the lake from Abu-Simbel to Aswan High Dam to assess the levels of the selected metals. The abundance of these metals was in the order of Fe>Mn>Zn>Cr>Ni>Cu>Pb>Cd, with mean concentrations of 12.41mg/g, 279.56, 35.38, 30.79, 27.56, 21.78, 11.21 and 0.183μg/g, respectively. Heavy metals are positively correlated with fine particles (mud fractions) and organic matter accumulation. The results showed perspicuous spatial high significant differences (P<0.01) for all the measured metals. Fe, Cr, Ni, Pb and Cd exhibited temporally high significant differences (P<0.01) before and after the flood period. Four Pollution Indices were used for the environmental assessment of Lake Nasser sediment. The indices included three single indices, Enrichment Factor (EF), Index of Geo-accumulation (Igeo) and Contamination Factor (CF). While the fourth, Pollution Load Index (PLI) was an integrated index. The pollution indexes confirmed that the Lake Nasser sediment was not contaminated with these elements. Sediments of Lake Nasser may be represented as a reference for the pre-industrial background of River Nile Sediments downstream Aswan High Dam

The potential impact of tourism, industrial, and urban activities on Egypt’s Red Sea coastline, which is well-known for its economic and environmental importance, was investigated at fifteen coastal sites. In the present study, the concentration of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in marine sediments from these sites, was determined using Inductively Coupled Plasma Mass Spectrometers (ICP-MS). In detail, various pollution indices, statistical analyses, and spatial distribution patterns were used to assess the pollution status, impacts of human activities, ecological risks, and sources of potentially toxic elements (PTEs) in surface marine sediment. A detailed comparison with up-to-date data was conducted. These sediments were composed predominantly of fine and very fine sands. Mean grain size distribution typically depends on the source of the sediment from the following two prime sources: terrigenous (autochthonous) and biogenic (allochthonous). The detected PTE mean concentrations were as follows: Fe > Mn > Zn > Cr > Ni > Pb > Co > Cu > Cd. Multivariate statistical analysis results revealed their close distribution and association. Cd and Pb levels in the studied area have been slightly impacted by anthropogenic inputs. According to the calculated pollution indices, although a minimal or moderate contamination degree was detected in the study area, it was determined that there was a low to moderate ecological risk. The slightly high degree of contamination and risk centered in the middle of the study area around phosphate mining and related activities. More attention should be given to the concentrations and sources of Cd, Ni, and Pb as the main pollution factors.

The rapid expansion of economic activities in Egypt’s Central Eastern Desert has resulted in poorly coordinated groundwater development, having a negative impact on the resource. This study was conducted to assess the hydrochemical characteristics of the different aquifers in the Central Eastern Desert, with an emphasis on the impact of seawater intrusion and groundwater quality for different purposes. A total of 21 groundwater samples were collected representing the three main aquifers (Eocene Carbonate, Nubian Sandstone, and Fractured Basement) in the Central Eastern Desert, and analyzed for major ions and trace elements. The majority of the samples had electrical conductivity values that exceeded the salinity limit for natural water. Groundwater saline load is primarily influenced by sodium, calcium, chloride, and sulfate concentrations. The groundwater in the Central Eastern Desert mainly consists of Na-Cl, Ca-Cl, and Na-SO₄ water-types. Saltwater intrusion and water-rock interactions via cation exchange and minerals weathering are the primary controlling factors of groundwater hydrochemistry. The high salinity of this groundwater renders it unsuitable for irrigation or consumption. Additionally, it is unfit for domestic use based on total hardness values. Furthermore, the Al, Cd, Fe, Mn, and Ni concentrations in the investigated groundwater exceed the allowable limits for human consumption. Proper mitigation measures and adaptation strategies are required for groundwater sustainability in the Central Eastern Desert.

Urban areas’ pollution, which is owing to rapid urbanization and industrialization, is one of the most critical issues in densely populated cities such as Cairo. The concentrations and the spatial distribution of fourteen potentially toxic elements (PTEs) in household dust were investigated in Cairo City, Egypt. PTE exposure and human health risk were assessed using the USEPA’s exposure model and guidelines. The levels of As, Cd, Cr, Cu, Hg, Mo, Ni, Pb, and Zn surpassed the background values. Contamination factor index revealed that contamination levels are in the sequence Cd > Hg > Zn > Pb > Cu > As > Mo > Ni > Cr > Co > V > Mn > Fe > Al. The degree of contamination ranges from considerably to very high pollution. Elevated PTE concentrations in Cairo’s household dust may be due to heavy traffic emissions and industrial activities. The calculated noncarcinogenic risk for adults falls within the safe limit, while those for children exceed that limit in some sites. Cairo residents are at cancer risk owing to prolonged exposure to the indoor dust in their homes. A quick and targeted plan must be implemented to mitigate these risks.

Wadi Abu Subeira area contains many farms and houses and is one of the promising areas for iron mining. Therefore, 21 surface soil samples were collected and investigated for toxic heavy metals (Pb, Cr, Ni, Cu, Zn, Co, and As) using inductively coupled plasma (ICP) to establish a geochemical baseline for these metals during pre-mining conditions. To decipher the sources of these metals and their interrelationships, multivariate statistical analysis was applied, while to evaluate the degree of pollution and potential environmental risks the environmental indices were used. Abundances of Pb, Cr, Ni, Cu, Zn, Co, and As fluctuated from 17.72 to 0.06, 47.12 to 10.86, 47.88 to 9.25, 45.04 to 6.23, 51.93 to 17.82, 10.55 to 1.24, and 7.04 to 1.66 mg/kg, respectively, displaying a declining trend of Zn > Cr > Ni > Cu > As > Co > Pb. Additionally, the mean concentrations of all studied metals were found to be significantly lower than the selected international reference standards. Pearson correlation coefficient, principal component analysis, and cluster analysis revealed two geogenic geochemical associations for the studied toxic elements: (1) Zn-As-Ni-Cr-Cu-Co; and (2) Pb. Negative I_geo values were observed for all metals, which showed that the samples were uncontaminated and can be considered a geochemical baseline for the study area. Moreover, all CF values were lower than or close to 1, suggesting low contamination levels from all studied metals and supporting the association with natural geological processes. Similarly, Er and RI values of all metals were below 40 and 150, respectively, indicating a low-risk environment. Ultimately, the obtained levels of the studied metals can be used as a geochemical baseline for tracking the future changes in their accumulations in soil sediments considering the current assessment of the area as an environmentally safe area.