Pollution Indices of Trace Metals in Urban Dumpsite Soils within Akwa Ibom State, Nigeria

Abstract

Surface soil samples were obtained from six (6) urban dumpsite soils namely: Uyo, Abak, Eket, Onna, Ikono and Ikot Ekpene within Akwa Ibom State, Nigeria. Control samples were also collected from a forest in Etinan local government area of the same State. Samples collected were treated and analyzed based on standard techniques to ascertain the pollution status of Pb; C d; Ni; Cr and Fe at each dumpsite soil and Control using geoaccumulation index (Igeo) and Contamination factor (CF) analysis. The source of metals to dumpsite soils and Control was identified using enrichment factor model. Pollution status of each dumpsite soil was also established using degree of contamination (Cdeg). Igeo results showed that, Pb, Ni and Cr moderately polluted dumpsite soils studied, Cd varied between unpolluted to moderately polluted status. However, Fe indicated very low Igeo values indi cating the low availability of the metal in the study area. Enrichment factor analysis showed that Pb and Cr were primarily from anthropogenic sources; Ni and Fe were mostly from natural source while Cd source varied between anthropogenic and natural at th e different dumpsite soils but the source of all the metals at Control site was natural. Contamination factor analysis disclosed that Cd, Ni, Cr and Fe moderately