Assessment and Source Apportionment of Heavy Metals in Soils Around Idunmwowina, Ovia North East, Nigeria

Authors: *Ojeaga, K. And Ehinlaiye, A.O.

DOI Info: http://doi.org/10.5281/zenodo.18061772

ABSTRACT

This study evaluates the concentration, contamination status, ecological risk, and potential sources of heavy metals in soils from Idunmowina, Ovia North East, Nigeria. Ten (10) soil samples were analyzed for Fe, Zn, Cu, Pb, Mn, Ni, Cd, Cr, and Co using Atomic Absorption Spectrophotometry (AAS). Mean concentrations were in the order: Mn (53.54 mg/kg) > Fe (25.7 mg/kg) > Cu (21.80 mg/kg) > Ni (8.43 mg/kg) > Cr (5.45 mg/kg) > Zn (2.51 mg/kg) > Pb (2.51 mg/kg) > Co (2.40 mg/kg) > Cd (0.72 mg/kg). Enrichment factors (EF < 2) indicated minimal enrichment and dominantly geogenic origin. Ecological risk assessment showed Cu (Eir = 10.9) as the most critical element, though the cumulative risk index (RI = 28.35) classified overall risk as low. The pollution load index (PLI = 0.2866–0.3073) and degree of contamination (Cd = 0.3586–2.6772) suggested slight to moderate contamination. Multivariate statistics provided further source differentiation. Correlation analysis revealed strong positive associations (Zn–Pb, Cr–Cd, Cu–Co) and a significant negative Cu–Mn relationship indicative of lateritic weathering. Cluster analysis grouped Fe–Cu separately from Cr, Ni, Cd, Co, Pb, and Zn, reflecting distinct input pathways. Principal component analysis (PCA) extracted four components accounting for 92.49% of the variance, with PC1 and PC2 dominated by anthropogenic signatures, while Mn was primarily geogenic. Overall, the soils exhibit heavy metal concentrations within regulatory thresholds. However, localized Cu enrichment highlights anthropogenic influence, necessitating continuous monitoring to mitigate potential ecological impacts

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