Abstract - journal of science
Abstract
DISTRIBUTION, SOURCES AND CONTAMINATION RISK ASSESSMENT OF SOME TRACE METALS IN BOTTOM SEDIMENTS FROM SELECTED LOCATIONS IN LAGOS LAGOON, SOUTH WESTERN NIGERIA

Lagos lagoon can be described as a depository of last resort for all the solid and liquid wastes generated in the adjoining land area. In order to assess the current trends in trace metal concentrations from crustal, industrial and domestic source ;Fe, Mo, Zn, Cu, Pb, Ni and Cr in bottom sediments from twelve stations in Lagos Lagoon, were analysed by Atomic Absorption Spectrophotometer (AAS) after acid digestion. The mean concentration of the sediments are as follows:11,425.74mg/kg(Fe), 367.75mg/kg(Mn), 259.78mg/kg(Zn), 14.94mg/kg(Cu), 13.27mg/kg(Pb), 9.38mg/kg(Ni) and 6.00mg/kg(Cr). Potential contamination benchmarks; contamination factor (CF), enrichment factor (EF), geoaccumulation factor (Lgeo) and pollution load index (PLI), were used to assess whether, the observed concentrations represent background and contaminated levels. Based on these; it was concluded that zinc metal represents a contaminated level in the analysed sediments, but the overall toxicity level of the Lagos Lagoon sediments to the aquatic biota is low