Distribution of heavy metals in sediments of Igbede, Ojo and Ojora rivers of Lagos, Nigeria
The distribution of some heavy metals, namely Cd, Pb, Zn, Fe, Cu, Cr and Mn in epipellic sediments of Igbede, Ojo and Ojora rivers of Lagos was studied weekly in the early summer (November) of 2003. The levels of selected trace metals were determined using Atomic Absorption Spectrophotometer (UNICAM 969 AAS SOLAR). Trends in heavy metal burdens in the sediments revealed weekly variations in all the rivers assessed. Statistical analyses also showed different mean levels of trace metals in the aquatic environments, the distribution of which followed the sequence Fe > Zn > Mn > Pb > Cu > Cr > Cd, Fe > Zn > Cu > Mn > Pb > Cr > Cd and Fe > Zn > Mn > Cu > Cr > Pb > Cd in Igbede, Ojo and Ojora rivers respectively. Fe recorded the highest concentration levels (1,582.95 ± 96.57 μ g/g–1,910.34 ± 723.19 μ g/g) in all the sediments investigated while the Cd levels (0.06 ± 0.10 μ g/g–0.47 ± 0.36 μ g/g) were the lowest. Expectedly, trace metal concentrations in fine grain muddy sediments of the Igbede and Ojo coastline were much higher than those of Ojora which consist of coarse and sandy deposits covering the near shore area. Generally, the results obtained fell within tolerable limits stipulated by World Health Organization (WHO).
KeywordsEpipellic sediments Heavy metals Igbede river Ojo river Ojora river
Unable to display preview. Download preview PDF.
- Ademoroti, C.M.A.: 1996a, Environmental Chemistry and Toxicology, Foludex Press Ltd., Ibadan, pp. 171–204.Google Scholar
- Ademoroti, C.M.A.: 1996b, Standard Methods for Water and Effluents Analysis, Foludex Press Ltd., Ibadan, pp. 111–120.Google Scholar
- Adams, W.J., Kimerle, R.A., and Barnett, J.W. Jr.: 1992, ‘Sediment Quality and Aquatic Life Assessment’, Environ. Sci. Technol. Pubs.acs.org/journal/esthag. 26, 1865–1875.Google Scholar
- Burton, G.A. Jr.: 1992, ‘Assessing Contaminated Aquatic Sediment,’ Environ. Sci. Technol. IAQ Publication 26, 1862–1863.Google Scholar
- Chapman, P.M., Rooberg, G.P., and Vigers, G.A.: 1982, ‘Design of Monitoring Studies for Priority Pollutants,’ J. Wat. Poll. Cont. Fed. 54, 277–292.Google Scholar
- Clark, R.B.: 1986, Marine Pollution, 3rd edn, Reinhold Publisher, United States of America, pp. 110–121.Google Scholar
- Forner, U.A. and Wittman, G.W.: 1993, Metal Pollution in Aquatic Environment, Springer Verlag: Berlin, 486p.Google Scholar
- Solomons, W. and Forstner, U.: 1984, Metal in the Hydrocycle, Springer Verlag: New York, pp. 21–22.Google Scholar
- Udosen, E.D.: 1992, ‘Aquo-terrestial Environmental Pollution Studies of Inorganic Substances from two Industrial firms in Akwa Ibom State,’ Ph.D Thesis. Dept. of Chemistry, University of Calabar, Calabar, 577p.Google Scholar
- Van, H., Timmermans, K.R., and Govers, H.A.: 1991, ‘Abiotic and Biotic Factors Influencing Insitu Trace Metal Levels in Macro Invertebrates In Fresh Water Ecosystems,’ Environ. Toxicol, Chem. 10, 275–292.Google Scholar