Heavy Metal Bioaccumulation in Highly Consumed Pelagic and Benthic Fish and Associated Health Risk.

The present study investigated the levels of Manganese (Mn), Cadmium (Cd), Copper (Cu), Zinc (Zn), Lead (Pb) and Iron (Fe) in the tissues of a benthic fish (Clarias gariepinus) and a pelagic fish (Oreochromis niloticus), which are highly consumed in Ghana. The fish were collected from the Weija reservoir, which is an important source of fishery and potable water in Accra, Ghana. The results indicate heavy metal accumulation in all the tissues (gills, liver and muscles) analyzed. The bioaccumulation of all the metals was lowest in the muscles compared to the liver and gills in both species. The bioaccumulation of the metals was generally higher in the tissues of the catfish, except for Fe and Zn. Fe was higher in the gills and liver of the tilapia, and Zn was higher in the liver of the tilapia. The analysis of relationships between metal levels in the different tissues and the size of the fish showed a few significant correlations. The results also showed that all metals showed no potential health risk to consumers, as THQs and TTHQs in tilapia and catfish were less than one, and the metal levels in both species were all below the FAO/WHO maximum permissible limits.

Preliminary Assessment of Trace Metal Pollution and Their Bioaccumulation in Mollusks Inhabiting the Intertidal Sediments of the Atlantic Coast of Accra, Ghana.

The present study investigated the trace metal levels in sediments, enrichment in sediments, and its bioaccumulation in mollusks collected from the intertidal sediments of the coast of Accra, Ghana, which is influenced by anthropogenic activities. The metals (Fe, Mn, Cu, Cr, and Zn) were analyzed in sediments. The metals (Mn, Cu, Cr, and Zn) were analyzed in the soft tissue of the mollusks collected from the different coastal areas. The results indicate that although Accra is the capital city and the coast receives tons of anthropogenic wastes, trace metal levels were low and there was no enrichment for the metals analyzed except Cu which showed minor to moderate enrichment in the coastal sediments. There was bioaccumulation of the trace metals in the soft tissue of the mollusks, and the results suggest that the mollusks studied, the gastropods (Agaronia razetoi) and the bivalves (Tivela tripla), can be used for biomonitoring.