Evaluation of the Contamination of Four Metal Trace Elements (ETM) of Tilapia Fish (Oreochromis niloticus) from Two Types of Fish Ponds in an Aquaculture Production Center in Côte d’Ivoire

Abstract

Trace Metal Element (ETMs) pollution in fish farming is becoming a concern due to difficult production conditions. This study investigated the level of contamination by four trace metals: lead (Pb), mercury (Hg), arsenic (As) and cadmium (Cd). ETM research focused on Oreochromis niloticus from two types of fish ponds in the Haut-Sassandra region of Côte d'Ivoire.  The health risk associated with tilapia consumption in this major production area was assessed. The concentration of Trace Metal Elements in fish was measured using a Perkin Elmer argon plasma emission spectrometer, Optima 3000 DV model. The physicochemical parameters of pond water were taken in situ with a multi-parameter. The physicochemical characteristics show that the Haut-Sassandra region is an area favorable to fish farming activity with a neutral pH, an average temperature of 30°C and a conductivity less than 300. As for ETMs, Low concentrations ranging from 0 to 0.040 mg/kg for tilapia, from 0 to 3.0147 mg/kg for sediments and from 0 to 0.3262 mg/kg for ponds water were observed in the matrices studied. Mercury and arsenic were found to be absent in Tilapia. The statistical analyzes carried out showed that the average concentrations of these ETMs are lower than the standards recommended by FAO and European Union. However, bioconcentration factors between 2 and 6 indicate that chemical pollutants in pond water and sediments have a negative impact on Oreochromis niloticus production, As for dam ponds / retentions basins, values less than 1 were obtained. This study reveals that the consumption of Tilapia from fish ponds in the Haut-Sassandra region could presents a low risk. The work has also shown that tilapia from bypass ponds / diversion basin are the most vulnerable to the ETMs studied.