Heavy Metal Pollution of Wetland Sediments in Some Cities of South-Western Nigeria

Abstract

Accumulation of metal contaminant in wetland sediment can pose serious environmental problem to public health, hence the evaluation of the geochemical impact of metals present in wetlands of Ibafo and Alapere environment. A total of thirty sediment samples were collected from fifteen sampling points at depths of (4cm-6cm) and (6cm-8cm) in the study area. Heavy metals concentrations were determined with the use of the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique. Microsoft Excel, statistical package for social sciences (SPSS) was employed for the data interpretation and Corel draw to generate geochemical maps. Geochemical results revealed Alapere to be highly contaminated than Ibafo which was due mainly to high anthropogenic activities found in the area. A strong and positive correlation was observed between the metals at both depths in Ibafo and Alapere which indicates that the metals have same relationships regardless of the depth and are governed by the same geochemical processes which is anthropogenic. Metal ratio revealed a high depletion of metals into the environment of Alapere as compared with that of Ibafo indicating high environmental pollution in Alapere. Geo-accumulation Index (Igeo) values of Alapere at both depths are very strongly contaminated as compared with the metals in Ibafo this is due to the industrial discharge, indiscriminate sewage disposal, metal smelting, and indiscriminate burning of tyres, indiscriminate disposal of electronic components found in the study area. In conclusion Alapere wetland soils are observed to be more contaminated than Ibafo, due to divers’ human activities found in the area. It has thus become imperative to establish timely monitoring and remediation strategies to alleviate the cumulative concentration of trace metals in the study area, to avoid any possible break-out of disease that could affect the public.