Trace metals in Lates niloticus and Rastrineobola argentea samples for human consumption at Winam Gulf of Lake Victoria

Abstract

Trace metals were determined in the two most abundant fish species in the Winam Gulf of Lake Victoria (Lates niloticus and Rastrineobola argentea). The results show that the concentratios of the metals have no significant difference (p < 0.05) among the different sampling sites for each species. This situation was attributed to the mobility trends of fish. The abundance trend of the metals in L. niloticus was Fe>Cu>Pb>Cd, while that of Rastrineobola argentea was Zn>Fe>Cu>Pb>Cd. The difference in the trends was attributed to the fact that Rastrineobola argentea is consumed wholly, while the internal organs of L. niloticus are gotten rid of before consumption. This same reason explains why the concentrations of the metals were significantly higher in Rastrineobola argentea compared to those in L. niloticus. Rastrineobola argentea was found to be a major source of trace metals intake by humans.

Keywords:

• trace metals
• human exposure
• fish
• Lake Victoria
• Kenya

Acknowledgements

We would like to thank the Alexander von Humboldt Foundation of Germany for a fellowship grant to Joseph O. Lalah. We are also very grateful to the Director, Institute of Ecological Chemistry, GSF and Neuberger for assistance.