Heavy Metal Dynamics in Commercial Fish Ponds in Ondo Town: Potential Health Risk

Adekolurejo, O.A; Osungbemiro, N.R1and Falowo, T. J

Department of Biology, Adeyemi College of Education, Ondo

Email Address:loyekolurejo@yahoo.com

Abstract: Bioaccumulation of heavy metal contaminants is potentially a serious threat to aquatic life and human health, especially when they exceed permissible thresholds in the environment. In this study, we monitored the concentrations of Fe, Cu, Zn, Pb and Cd in water, sediment and tissues of Catfish, Clarias gariepinus obtained from commercial fish ponds in Ondo town, for their public health risks. Heavy metal concentrations in fish muscle, liver, gills and intestines, as well as in water and sediments were determined respectively using Atomic Absorption Spectrophotometry (AAS). Data on heavy metal concentrations and fish morphometry were analysed and presented as descriptive statistics. Results obtained showed that the mean± SD values of all the metals in water samples were higher than the standard permissible limits for fresh water and biota, when compared with national and international water quality guidelines. Analysis of metals in sediments showed accumulations in the following sequence Fe>Zn>Pb>Cu >Cd. The highest and least accumulations for all the metals were recorded in the gills, and in the liver respectively. Levels of metals obtained in this study suggests the presence of heavy pollution in the ponds, as a results, consumption of fish from their ponds maybe unsafe. Hence, regular monitoring should be considered a regulatory priority.