Geochemical fractionation, mobility of elements and environmental significance of surface sediments in a Tropical River, Borneo

A holistic approach to distribution, ecotoxicology, and human health risk of potentially hazardous emerging pollutants along the Egyptian Mediterranean coast: Univariate and multivariate analyses

This study examines pollution, ecotoxicological, and health risks of B, F, and S in seawater and sediments along the southern Mediterranean Sea. Strong positive loading on B in sediment, PLI, and NPI suggested that the high B content raises the total amount of contamination and cumulative risks to benthic organisms. Logkd for S and F were <3 indicating that they were easily transported to the water column. While, B has potential to be released to seawater (3 < Logkd < 4), which potentially endanger benthic organisms. Human health risk associated with the current exposure to B, F, and S in sediments was not notable (THQS < 1), but there is still cause for concern, particularly given the remarkable health risk associated with the oral ingestion of F and B from seawater (HQWIng > 1). Toxicological investigations of short-term and long-term exposure explored potentially high ecotoxicological risks among aquatic organisms, invertebrates were the most sensitive species.

Chemical speciation and comprehensive risk assessment of metals in sediments from Nabq protectorate, the Red Sea using individual and synergistic indices

The study evaluates metal concentrations, distributions, contamination, risk, sources, fractionation, and mobility in Nabq Protectorate sediments, revealing a metal content order of Fe, Mn, Pb, Ni, and Cd. Metals are dominated by residual fractions, with Cd (83.70 %) > Ni (82.98 %) > Pb (80.96 %) > Fe (80.31 %) > Mn (76.65 %) reflecting the natural sources of investigated metals. Mn (23.35 %) was the most abundant mobile metal, and the sediments of the protectorate had low toxicity and moderate risk according to the synergistic indices (1 ≤ mRAC<10 and ERM; 5-10). The results from the proposed individual indices showed that Mn, Fe, and Pb are the most bioavailable (BIM 0.1-0.4), Cd, Mn, Ni, Fe, and Pb are of moderate mobility (MIM 0.1-0.4), and Cd is the most available (ARIM 5-10), with Cd posing the most ecological risk. The total hazard quotient (THQ) for child was greater than one, exposure to manganese through ingestion and skin contact while swimming may endanger human health.