Assessment of some heavy metals contamination in the soil of river Niger floodplain at Jebba, central Nigeria

The assessment of heavy metal contaminants: Mn, Cr, V, Cu, Pb, Zn and Ni, was conducted on River Niger Floodplain soil at Jebba, Central Nigeria using Contamination Factor (Cf), Factor (AF), Enrichment Factor (EF), Geoaccumulation Index (Igeo) and Degree of Contamination (Cdeg). Random sampling method was adopted cutting across the entire floodplain and the samples were subjected to Inductively Coupled Plasma Mass Spectrometry (ICP/MS) and X-Ray Fluorescence (XRF) methods of analyses. The computed results from the contamination indexes revealed an average AF value of 2.2, 0.8, 0.6, 1.7, 0.2, 0.5 and 1.3 for Mn, Cr, V, Cu, Pb, Zn and Ni respectively. The respective average of EF is: 1.1, 0.5, 0.2, 0.6, 0.1, 0.2 and 0.4. The average Igeo are generally <1. The degree of contamination ranges from low to moderate (2.5 to 14.2). The Cf shows that the soil samples are moderately contaminated with Mn, Cu and Ni (range=1.3 to 2.2) while Cr, V, Pb, and Zn show low contamination factor (range=0.2 to 0.8). Results also show that the source of contamination of Mn, Cu and Ni are by the various anthropogenic activities in the area and the influence of geogenic processes is prevalent on Cr, V, Pb and Zn in the soil samples.