Distribution and sediment quality of heavy metals in riverine sediments in Kumasi, Ghana

Heavy metals pose significant environmental concerns due to the threats they pose to ecosystems and human health. This study assessed heavy metal pollution in riverine sediments of Kumasi and evaluated associated human health risks. Sediment samples (n = 41) were analyzed for Pb, Zn, Cd, Cr, Hg, As, Cu, Ni, and Fe using portable X-ray fluorescence and mercury analyzer techniques, alongside measurements of pH, electrical conductivity, and total organic carbon. Pollution indices, including the geoaccumulation index, contamination factor, enrichment factor, and pollution load index (PLI), were computed. Mean concentrations of most metals were below Canadian Council of Ministers of the Environment (CCME) thresholds; however, cadmium exceeded the Severe Effect Level in some samples (max = 11.42 mg/kg), and arsenic exceeded the Probable Effect Level at hotspots (max = 16.22 mg/kg). The PLI value of 1.397 indicates moderate contamination. Continuous exposure can pose ecological and human health risks, particularly in areas enriched with cadmium and arsenic. Targeted monitoring and risk mitigation are recommended.