Contamination Factor, Enrichment Factor and Pollution Load Index of Heavy Metals in Soils from Abandoned Pb-Zn Mines and Active Quarries in Ebonyi State, Southeastern Nigeria

This study examines the level of heavy metal pollution in the soils collected from abandoned lead-zinc mines in Enyigba, Ameri, and Ameka, as well as the soils of active mines in Ezza South, Ezza North, and Ivo in Ebonyi State, Nigeria. A total of Thirty-three (33) soil sample sourced out and subjected to Atomic Absorption Spectrophotometric analysis of Cr, Cd, Cu, Zn and Pb. Basic soil parameters such as pH, total organic carbon, and electrical conductivity were measured by titration. The level of contamination was determined by calculating the Contamination Factor, Pollution Load Index, and Enrichment Factor using local background data and Zn as a geochemical normalizer. The outcome shows that Cd and Pb in the soils of abandoned mines in Enyigba, Ameri, and Ameka are very highly contaminated, whereas Cr in the soils of abandoned mines in Enyigba, Ameri, and Ameka, as well as the soils of active mines in Ezza South, Ezza North, and Ivo in Ebonyi State, Nigeria, are moderately contaminated. The Pollution Load Index ranges from 4.93 to 10.75 in the soils of active mines in Ezza South, Ezza North, and Ivo, while the PLI ranges from 1.77 to 7.57 in the soils of abandoned mines in Enyigba, Ameri, and Ameka. The Enrichment Factor indicates that Cd in the soils of abandoned mines in Ameri, Ameka and Eyingba in Ebonyi State, Nigeria, is extremely severely enriched, whereas Pb and Cu in the soils of abandoned mines in Enyigba, Ameri, and Ameka in Ebonyi State, Nigeria, are moderately to severely enriched. Multivariate analysis indicates that Cd,Cu, Zn, Cu, and Pb in the soils sourced from abandoned mines in E Ameri, Ameka and Enyigba in Ebonyi State, Nigeria, emanate from man, whereas Cr emanates from the earth. The study provides crucial information for the formulation of environmental remediation policy in the metallogenic province of Nigeria.