CONTAMINATION INDICES OF TRACE METAL IN SOIL FROM ABADONED OPEN WASTE DUMP SITE AT IKOT ABASI STREET, UYO.

ABSTRACT The contamination indices and levels of trace metals in soil from abandoned open waste dumpsite and control site at Ikot Abasi Street, Uyo was assessed using models postulated by USOPA and levels of the trace metals in soil was determined using atomic absorption spectrometer (AAS). The result revealed that the two samples contain measurable concentrations of trace metals. The result for the dumpsites, the concentration of metals were as follows, Chromium (10.507 ± 0.004), Iron (41.642 ± 0.061), Zinc (26.346 ± 0.008), Copper(1. 191 ± 0.001), Lead (1.195 ± 0.060), and Cadmium(1.643 ± 0.007) respectively, while at control sites (100m away from dumpsites) the concentration ranged from chromium (9.733 ± 0.020), Iron (38.565 ± 0.102), Zinc (24.350 ± 0.0130), Copper (1.100 ± 0.001), Lead (1.075 ± 0.060), and Cadmium (1.521 ± 0.230) respectively. All the investigated metals were lower than the WHO permissible limit except Cadmium and iron. The contamination factor (CF) values for all metals (Fe, Cr, Cd, Zn Cu, Pb,) recorded values between 1.08 and 1.11 according to (Hakanson, 1980), Cf values between 1 and 3 indicate moderate contamination. Enrichment Factor (Ef) values for (Cr, Fe, Pb, Zn and Cd) are close to 1, indicating minimal enrichment and a natural origin of those metals while Cd has a slightly elevated Ef of 1.22 which may suggest minor anthropogenic contribution. The pollution index (PLI) was 7.663. the geoaccumulation index (Igeo) values for all metals Cr, Fe, Cd, Cu, Pb, the geoaccumulation index (Igeo) ranged from -0.47 for Cr, Fe, Cu and Cd while Pb range is -0.43, Zn ranged -0.46 classifying the soil as uncontaminated to moderate contamination. The elevated contamination of trace metals in soil are the major threats to the soil ecosystem. The study highlight the need for legislation to control the indiscriminate discharge metal containing waste which can affect edible plant around dumpsite thereby posing human health risk.The result indicates that the dumpsite was contaminated with the investigated trace metals when compared to the control site, thus, appropriate remediation method should be employed in other to reclaim the soil.