Elemental pollution status of different components of Ologe Lagoon, Lagos, Nigeria

This study evaluated the concentrations and distributions of nutrient and non-nutrient elements in water, sediment, mud, and vegetation of Ologe Lagoon, Lagos, Nigeria. Nutrient elements including Na, Ca, K, and Mg were found in high concentration values in the different components of the freshwater ecosystem. While the water had the least concentration of the elements, Trapa natans had the highest. Aluminium showed similar distribution patterns in the different components, except for T. natans. All the samples correlated significantly with water (p <0.05). Both the sediment and mud showed low potential ecological risk indexes of 5.3 and 5.92, respectively. Copper had the highest ecological risk with respect to single regulator indexes in the mud and sediment, notwithstanding its low concentration in the two components. Pollution indices suggested the low severity of non-nutrient elemental contamination of water, sediment, mud, and vegetation of Ologe Lagoon, and therefore, it is safe for human consumption, but not for agricultural irrigation. Pistia stratiotes and T. natans showed potentiality for use as photo-stabilisers and phytoremediators for some of the elements. The presence of radionuclides and rare earth elements in the components of Ologe Lagoon are instructive for specific policy initiatives to mitigate their effects on the population. HIGHLIGHTS Radionuclides were reported in the components of Ologe Lagoon, a freshwater ecosystem.; High nutrient-element concentration associated with increased salinisation were found in the different components of Ologe Lagoon.; There is a low contamination of the components of the Lagoon with respect to non-nutrient elements.; Water from Ologe is unsuitable for agricultural irrigation owing to high concentration of nutrient metal elements.; Pistia stratiotes and T. natans showed potential for the remediation of Zn, Cr, Cu, Th, and U.