ASSESSMENT OF HEAVY METAL STATUS AROUND MAJOR INDUSTRIAL SITES IN SOUTHERN CROSS RIVER STATE, NIGERIA USING ATOMIC ABSORPTION SPECTROPHOTOMETER (AAS) METHOD

ABSTRACT

This research focuses on assessment of heavy metal concentration in the soils of industrial areas in Southern Cross River State. Soil samples in the immediate vicinity of some selected industrial sites at 15cm deep were collected in five sample locations of Southern Cross River state which include, Gitto Company, Zenith construction Ltd. Faith Plant, and UNICEM. This was done to evaluate the status of heavy metals (Fe, Cd, Co, Cu, Pd, Cr, Zn, Ni & Mn) present. The soil samples were subjected to a total digestion technique using HNO3 and HClO4 acids and analyzed using Atomic Absorption Spectrophotometer for the metals stated above. The metal concentration in ppm in all the site ranges from l63.35ppm – 2262ppm for Fe, 18.80ppm – 33.25ppm for Cd,

3.53ppm – 4.48ppm for Co, 21.40ppm – 38.10ppm for Cu, 22.55ppm for Pb, 6.10ppm – 15.12 ppm for Cr, 9.50ppm – 44.35ppm for Zn, 5.40ppm – 46.30ppm for Ni and 10.43ppm – 64.20ppm for Mn. The concentration of the various heavy metals showed a wide range of variation with variable pattern in the order Fe>>Mn>Ni>Zn>Cu>Cd>Pd>Cr>Co in the entire sample area. Significant enrichments were obtained for Cd, Cu, and Zn respectively at Unicem, but Pb was not significantly enriched in any sample location. The contamination index in this study ranged from uncontaminated (0) to moderately contaminated (1-2). The concentration of heavy metals in this study falls below the regulatory standard of other countries apart from Cd, an element associated with quarry and mining activities, waste batteries, and metal finishing industrial waste having concentration above the regulatory level of other countries.

Keywords: Heavy metals, soil, quarry activities, industries, contamination.