Distribution and Speciation of Heavy Metals in Water and Sediments of the Coastal Marine Areas of Tanzania
- 1 Department of Aquatic Sciences and Fisheries, University of Dar es Salaam, Dar es Salaam, Tanzania
- 2 Department of Aquatic Sciences and Fisheries, University of Dar es Salaam, Dar es Salaam, Tanzania
- 3 Department of Aquatic Sciences and Fisheries, University of Dar es Salaam, Dar es Salaam, Tanzania
Abstract
The present study investigated the concentration and species of heavy metals As, Hg, Cr, Pb and Zn in water and As, Hg, Cr, Pb and Zn in sediments collected along the coastal marine areas of Tanzania so as to determine their behaviour and remobilization potential in the environment and the degree of their availability to edible aquatic biota for monitoring purposes. Sequential extraction revealed the presence of a significant proportion of heavy metals Cr, Pb and Zn bound to available fractions of sediments. Arsenic had the highest concentration in non available residual fractions. PCA analysis found that As-Hg, Cr-Pb were strongly correlated and that the two may be derived from the same source most likely from storm water drainage of waste water discharges, while Zn may have come from the different source like watershed erosion. Further, PCA clearly confirms the same. Generally, Zn among all heavy metals analysed was the most available to aquatic biota due to its higher average concentrations in the acid soluble fraction, followed by chromium. However, high percentages of metal species studied in Tanzania coastal marine areas were found in non available fractions which indicated that the edible aquatic biota was safe for human consumptions.
- Florence, T.M. (1986) Electrochemical Approaches to Trace Element Speciation in Waters. Analyst, 111, 489. https://doi.org/10.1039/an9861100489
- Lopez-Sanchez, J.F., Rubio, R., Samitier, C. and Rauret, G. (1996) Trace Metal Partitioning in Marine Sediments and Sludge Deposited off the Coast of Barcelona (Spain). Water Research, 30, 153-159. https://doi.org/10.1016/0043-1354(95)00129-9
- Kozelka, P.B. and Bruland, K. (1998) Chemical Speciation of Dissolved Cu, Zn, Cd, Pb in Narragansett Bay, Rhode Island. Marine Chemistry, 60, 267-282. https://doi.org/10.1016/S0304-4203(97)00107-2
- Florence, T.M. (1982) The Speciation of Trace Element in Waters. Talanta, 29, 345-364. https://doi.org/10.1016/0039-9140(82)80169-0
- Kersten, M. and Forstner, U. (1991) Speciation of Trace Elements in Sediments. In: Batley, G.E., Ed., Trace Element Speciation: Analytical Methods and Problems, CRC Press, Boca Raton, 245-317.
- Waldichuk, M. (1985) Biological Availability of Metals to Marine Organisms. Marine Pollution Bulletin, 16, 7-11. https://doi.org/10.1016/0025-326X(85)90252-8
- Ure, A.M., Quevauviller, Ph., Muntau, H. and Griepink, B. (1993) Speciation of Heavy Metals in Solids and Harmonization of Extraction Techniques Undertaken under the Auspices of the BCR of the Commission of the European Communities. International Journal of Environmental Analytical Chemistry, 51, 135. https://doi.org/10.1080/03067319308027619
- Schwarz, K. (1977) Essentiality versus Toxicity of Metals. In: Brown, S.S., Ed., Clinical Chemistry and Chemical Toxicology of Metals, Elsevier/North Holland, Amsterdam, 3-22.
- Dinu, C., Vasile, G. and Popescu, L.R. (2011) Determination of Volatile Metallic Elements in Water Using Flow Injection Hydride Generation Coupled with FIAS-ICP-OES. INCD ECOIND—International Symposium SIMI 2011 “The Environment and the Industry”, Vol. 2, 147-154.
- Nelson, D.W. and Sommers, L.E. (1996) Total Carbon, Organic Carbon, and Organic Matter. In: Page, A.L., et al., Eds., Methods of Soil Analysis, Part 2, 2nd Edition, Agronomy No. 9, American Society of Agronomy Inc., Madison, 961-1010. https://doi.org/10.2136/sssabookser5.3.c34
- Yuan, C., Shi, J., He, B., Liu, J., Liang, L. and Jiang, G. (2004) Speciation of Heavy Metals in Marine Sediments from the East China Sea by ICP-MS with Sequential Extraction. Environment International, 30, 769-783. https://doi.org/10.1016/j.envint.2004.01.001