Determination of water quality, trace elements contamination in Oreochomis niloticus and Clarias gariepinus reared in 2 types of ponds and health risk assessment in Cameroon

Abstract

Background: Fish farming in Cameroon is growing very rapidly and fish available in the markets is mostly coming from fish farms, but domestic fish production is still low to meet demand. Intensification of production could lead to the occurrence of various types of contaminants that can affect the sanitary quality of farmed fish and consumer health. This study aimed to assess the quality of farmed fish collected in fish farms located in four regions of Cameroon (Center, South, West, Littoral).Results: Concentrations of arsenic, cadmium, lead, chromium, cobalt, and nickel were determined in pond water and muscles of Oreochromis niloticus and Clarias gariepinus raised in concrete and earthen ponds to evaluate health risk for consumers. Trace elements were determined using Inductively Coupled Plasma Optical Emission spectrometry (ICP-OES). Heavy metals in water for concrete and earthen ponds shows there are no significant differences (p<0.05) between the rearing systems except for cobalt and nickel. Heavy metals concentrations in water were lower when compared to the WHO recommended limits except for cadmium in all the ponds. For concrete ponds, heavy metal concentrations decreased in water in the sequence of Cd > As > Co > Ni > Cr > Pb. For earthen ponds the concentrations decreased as Cd > Co > As > Ni > Cr > Pb.Conclusion: Concentrations recorded in the muscles of the 2 species were above the safety limits recommended by FAO/WHO. The target hazard quotient of As was highest compared to other metals and higher than the acceptable limits according to US Environmental Protection Agency guidelines in all fish species. the level of each investigated metal, highlighted a very low health risk for consumers.