Heavy Metals, Profile of the Proposed Dump-Site at Ntak-Inyang Itam, Akwa Ibom State, Nigeria

Abstract

Levels of trace metals (Cr, Cd, Mn, Fe, Cu, Co, Ni, V, Zn and Pb) in soil from Ntak-Inyang Itam, Itu Local Government Area were determined using standard analytical procedures involving the use of atomic absorption spectrophotometry. Results of the analysis shows that at the debt of 0-15cm at five locations distributed in the area, Cr at sample sites B and E had a mean value of 5.00± 0.55µg/kg which is lower when compared to sample sites A, C and D. Also Cr in the study area had a coefficient of variation (C.V) of 3.14% which signifies stability. Cd in the four sampling points (A, B, C and E) seems to maintain a constant mean value of 0.14± 0.01µg/g except for point D (Esuk in Ntak-Inyang) which has a mean concentration of 0.19± 0.02µg/g. Mn exhibited different mean value at different (five) sampling points and a C.V of 1.99% which was the least and the most stable in the area among the ten metals analysed. Fe exhibited the highest concentration in all the sampling points, with a C.V of 4.99%. The result of analysis of copper (Cu) shows a total mean concentration of 8.29± 0.67µg/g while Cobalt (Co) in the four sampling points had the same mean value of 0.11± 0.1µg/g except in sample point A (sloping area of AKRUBEL) which increases to a value of 0.22± 0.6µg/g. Nickel (Ni) in sampling point C and D exhibited the same mean value of 0.83± 0.9µg/g while other sampling points (A, B, D and E) the mean varies. Vanadium (V) in the samples were generally low, sample point A and D had a mean concentration of 0.10± 0.01µg/g. Sample point C, D and E had 0.05± 0.01µg/g each. Zinc (Zn) had a mean concentration of 2.72± 0.60µg/g and a C.V of 10.4% while Lead (Pb) stood at a C.V of 3.2%. The results were compared with various National and International standards, on the whole the area was not found to be polluted by these metals. Hence the area is suitable for sitting the dump-site, with intermittent monitoring.