This study assessed the content, spatial pattern, and ecological and health risks of heavy metals in sediments of Hankorab area, Red Sea coastline, southern Egypt. Twenty surface sediment samples were collected and analyzed for nine heavy metals using ICP-OES. Levels of Ba, Pb, Cr, Ni, and V exceeded Canadian soil quality guidelines and the Earth’s crust background, whereas those of Pb, Cr, and Ni surpassed their respective effect range median (ERM) and probable effect level (PEL), implying possible negative impacts on the local biota. The findings of Pearson correlation and cluster analysis of sediment grain size, pH, total organic matter (TOM), and heavy metals confirmed those obtained from Factor analysis (FA). FA showed three factors comprising significant loadings of metals examined; Co, Cu, and Zn (F1: 21.8% of data variance from anthropogenic sources), Ba, Pb, Ni, Fe, pH, and TOM (F2: 20.7% associated with mining sites and rock weathering), and Cr, V, Mud%, and Sand% (F3: 18.8% from mixed sources). Enrichment showed background (Ba), minimal (Co, and V), moderate (Ba, Cu, Cr, Ni, and Zn), and significant (Pb) metal enrichment. Contamination factor indicated low (Fe), moderate (Ba, Co, Cu, Cr, Ni, Zn, and V), and considerable (Pb) contamination. Geo-accumulation index of all metals indicated extremely contaminated sediments (Igeo >5). The potential ecological risk index (PERI) of the metals showed a low risk (PERI < 150). The mean effects range median quotient (MERMQ) value (0.85) showed medium-to-high priority risk (0.51 < MERMQ ≤ 1.5), toxic risk index (TRI) value (11) showed moderate toxicity risk (10 < TRI ≤ 15), and the modified hazard quotient (mHQ) value (1.99) showed moderate severity of contamination (1.5 ≤ mHQ < 2.0). The non-carcinogenic risk index (HI) values indicated no chronic risk (HI < 1), and the total cancer risk (TCR) values were below the global safe limit (1 × 10− 4). Natural radionuclides (232Th, 226Ra, and 40K) were measured by NaI detector in Hankorab sediments and spatially distributed and assessed. The mean activity concentration of 232Th, 226Ra, and 40K activity in the samples were 23.01 ± 5.15, 20.27 ± 6.06, and 206.27 ± 61.84 Bq/kg, respectively. The radiological risk indices including gamma index (Hγ), alpha index (Hα), and internal and external indices (Hin & Hex) were higher in the northern and central sites, being below the recommended global limits.

Assessing the radioactive properties and environmental risks of Hankorab sediments on the Red Sea coast

期刊论文
发表日期：

2025年7月15日

查看全文

El Saeed R. Lasheen,
Gehad M. Saleh,
Bandar A. Al-Mur,
Ahmed Abdelaal

摘要

This study assessed the content, spatial pattern, and ecological and health risks of heavy metals in sediments of Hankorab area, Red Sea coastline, southern Egypt. Twenty surface sediment samples were collected and analyzed for nine heavy metals using ICP-OES. Levels of Ba, Pb, Cr, Ni, and V exceeded Canadian soil quality guidelines and the Earth’s crust background, whereas those of Pb, Cr, and Ni surpassed their respective effect range median (ERM) and probable effect level (PEL), implying possible negative impacts on the local biota. The findings of Pearson correlation and cluster analysis of sediment grain size, pH, total organic matter (TOM), and heavy metals confirmed those obtained from Factor analysis (FA). FA showed three factors comprising significant loadings of metals examined; Co, Cu, and Zn (F1: 21.8% of data variance from anthropogenic sources), Ba, Pb, Ni, Fe, pH, and TOM (F2: 20.7% associated with mining sites and rock weathering), and Cr, V, Mud%, and Sand% (F3: 18.8% from mixed sources). Enrichment showed background (Ba), minimal (Co, and V), moderate (Ba, Cu, Cr, Ni, and Zn), and significant (Pb) metal enrichment. Contamination factor indicated low (Fe), moderate (Ba, Co, Cu, Cr, Ni, Zn, and V), and considerable (Pb) contamination. Geo-accumulation index of all metals indicated extremely contaminated sediments (I_geo >5). The potential ecological risk index (PERI) of the metals showed a low risk (PERI < 150). The mean effects range median quotient (MERMQ) value (0.85) showed medium-to-high priority risk (0.51 < MERMQ ≤ 1.5), toxic risk index (TRI) value (11) showed moderate toxicity risk (10 < TRI ≤ 15), and the modified hazard quotient (mHQ) value (1.99) showed moderate severity of contamination (1.5 ≤ mHQ < 2.0). The non-carcinogenic risk index (HI) values indicated no chronic risk (HI < 1), and the total cancer risk (TCR) values were below the global safe limit (1 × 10^− 4). Natural radionuclides (²³²Th, ²²⁶Ra, and ⁴⁰K) were measured by NaI detector in Hankorab sediments and spatially distributed and assessed. The mean activity concentration of ²³²Th, ²²⁶Ra, and ⁴⁰K activity in the samples were 23.01 ± 5.15, 20.27 ± 6.06, and 206.27 ± 61.84 Bq/kg, respectively. The radiological risk indices including gamma index (H_γ), alpha index (Hα), and internal and external indices (H_{in &} H_ex) were higher in the northern and central sites, being below the recommended global limits.