Ecological Risk Assessment of Trace Metals in Bottom Sediments of Damba Dam Gusau, Zamfara State, Nigeria
Article | Published Aug, 2025Abstract
Pollution and ecological risk indices give qualitative and quantitative information on an ecosystem’s status. This study assessed the pollution level and environmental risk of Cd, Cr, Pb, and Zn in Damba Dam sediments using Atomic Absorption Spectroscopy (AAS) and pollution indices (geo-accumulation index, contamination factor, pollution load index, Nemerow pollution index, and potential ecological risk index). The results showed the concentration of the metals as follows: Zn (0.04±19.45 mg/kg upstream, 0.03±21.78 mg/kg middle stream, 0.04±6.52 mg/kg downstream), Pb (0.04±4.88 mg/kg upstream, 0.01±18.09 mg/kg middle stream, 0.01±11.10 mg/kg downstream), and Cd (0.00±15.03 mg/kg upstream, 0.01±39.70 mg/kg middle stream, 0.01±55.38 mg/kg downstream), with geo-accumulation index values of 0.00 (Zn), 0.00 (Pb), 0.00 (Cd) upstream, 0.00 (Zn), 0.02 (Pb), 0.00 (Cd) middle stream, and 0.00 (Zn), 0.02 (Pb), 0.00 (Cd) downstream, pollution load index values of 0.03, 0.01, and 0.01, and Nemerow pollution index values of 0.00, 0.03, and 0.03 showing a decrease in pollution from upstream to downstream, with no ecological risk posed by the metals (potential ecological risk index < 150, Er < 40). No significant ecological risk is associated with trace metal contamination in Damba Dam sediments. The study therefore, recommends that trace metals in the dam’s sediments should be monitored for effective management, and conservation of Damba Dam’s ecosystem in order to prevent possible ecological and human health risks.
