Assessment of heavy metal contamination in water and largescale yellowfish (Labeobarbus marequensis, Smith 1841) from Solwezi River, North-Western Zambia

Abstract

AbstractThe contamination of heavy metals in the Largescale Yellowfish (Labeobarbus marequensis) from the Solwezi River in North-western Zambia was investigated. The fish were captured from three different sampling sites on the Solwezi River. Site I was located before the mining effluents could join the river, site II was located immediately after the entry point of the mining effluent into the river, while site III was located downstream of where the effluents from the mining company had joined the river. The water and fish organs (muscle, gills, and liver) were checked for contamination with heavy metals. The values were compared with the established permissive levels considered safe for human consumption by the World Health Organization (WHO), and the Food and Agriculture Organization. In decreasing order, the contamination levels in fish organs were: Fe > Zn > Cu (gills), Fe > Zn > Cu (liver) and Zn > Fe > Cu (muscle). Co, Mn, and Pb were not detected in all the parts of the fish investigated. In water, the concentrations were in the order Zn > Fe > CU. The Metal Pollution Index (MPI) showed that site II was the most concentrated with heavy metals, while the gills were the most concentrated part of the fish. These results showed that the levels of the heavy metals investigated in the water and fish were within permissive levels by WHO and FAO. However, future expansion of existing companies and the introduction of new ones should strictly be monitored and their risks studied to safeguard fish and other aquatic products.

Keywords

• Bioaccumulation
• metals in fish organs
• human health risk
• metal pollution index
• toxicity
• Zambia