Temporal distribution of trace metals pollution load index in the Nile Delta coastal surface sediments

The Mediterranean coastal area of the Nile Delta is socio-economically vital, however, it is under significant environmental stress due to pollution from land-based activities. The study investigates the temporal variations of trace metals to assess the development of the anthropogenic pollution status in the coastal sediments. The average concentrations, the enrichment factor, and the geoaccumulation index revealed that Cr, V, Ni, and Co are pollutants of concern. Trace metals are particularly accumulating in the sediments further offshore and in the middle and eastern sectors of the Nile Delta coast. The temporal patterns of the pollution load index (PLI) along the Nile Delta coastal indicate that pollution hotspots are increasingly exposed to trace metals pollution over time. This is linked to discharges from anthropogenic land-based activities and controlled by sedimentological factors. A conceptual model for the accumulation of trace metals in sediments is proposed based on this study.