Integrated Characterization of Toxicity Distribution of Selected Heavy Metals in Stream Sediments Around Itakpe Iron Ore Mines, North Central Nigeria

The results of the analysis were subjected to five (5) indices: contamination factor (CF); Ecological risk factor (Er i ); Enrichment factor (EF); index of geo-accumulation (Igeo) and anthropogenic factor (AF). The CF results showed that the River PomPom dry and wet season sediments were collected in February and July respectively from 0cm to 10cm depth. Stainless steel spoon was used to collect the samples. The sediment samples were packaged, labeled and refrigerated for onward transportation to the laboratory. All samples were oven-dried (50 o C) for about 24 hours, sieved through -80 mesh. About 1.0g of each sample was digested, filtered and the filtrates were ready for heavy metal analysis using Atomic sediments were most contaminated with Fe in both seasons, least contaminated with Cd at dry season and Zn in wet season. The Er i factor revealed pollution hazard level of middle during wet season and tiny in dry season. Pb and Ni showed strong and middle hazard level during wet season and Cu revealed middle level during dry season. The enrichment factor indicated extremely enriched for Fe in all locations in both seasons while most heavy metals showed depletion to minimal enrichment. The Igeo for both seasons showed that Fe was moderately to highly polluted in all locations. During dry season, other heavy metals showed moderately to unpolluted while in wet season Cd, Ni and Pb indicated moderately to very highly polluted. In both seasons, the % AF was very high for Fe, Cu, Pb. The AF% was very high for Ni and Cd in wet season. All sites in both seasons have experienced deterioration but more in the wet season. From these indices, the stream sediments have been significantly contaminated with Fe, Ni, Pb and Ni in most locations in both seasons.