Assessment of metal distribution and pollution indices in the surface sediments along the western Egyptian Mediterranean Sea Coast”

Metals enter aquatic systems directly from anthropogenic sources, natural, and atmospheric deposition. Sediment is an essential component of aquatic ecosystems; it serves as a habitat for a variety of aquatic organisms. Due to their non-biodegradability, metals are among the most harmful pollutants in aquatic environments. The purpose of this study is to evaluate the levels of Mn, Fe, Cu, Pb, Zn, Ni, Cd, and Co verified from a total of 29 surface sediment samples collected along the western Mediterranean coast of Egypt in 2020—i.e., from Abu Qir Bay, al-Mex Bay, and Marsa Matrouh. It also aims to assess the ecological risk related to metal levels in sediments. The results revealed that metals followed a decreasing concentration sequence on average: Fe > Mn > Zn > Pb > Co > Ni > Cu > Cd. Both the geo-accumulation index (I_geo) and the pollution load index (PLI) showed that Abu Qir Bay sediments are moderately polluted; al-Mex Bay sediments are slightly polluted and Marsa Matrouh sediments are unpolluted. A multivariate statistical analysis was used, including Pearson correlation analysis and clustering heatmap, where the results are classified into two clusters according to their sources.