Assessment of Heavy Metals in Fish Tissues of Tilapia and Catfish from River Hadejia, Northern Nigeria

Kidney failure has become a growing problem at Hadejia Emirates over the last decade. This can be attributed to water pollution, possibly due to heavy metal contamination of River Hadejia that affects organisms living in it, such as fish. This study is aimed to determine the concentration of heavy metals (As, Cd, Cr, Pb) in two fish muscles. The research was conducted on tilapia and catfish where two samples of both fishes were used. The fish tissues were cut and oven-dried at 110 °C, and then a motor and pestle were used to powder the dried fish sample. A wet digestion method was used based on the analytical methods for Atomic Absorption Spectrometry (AAS). The result obtained shows that the concentrations of heavy metals (Cr, Cd, As and Pb) in both fishes were found to be 0.3220 ± 0.0028; 0.1656 ± 0.002 (𝑚𝑔/𝑘𝑔), 0.0319 ± 0.0018; 0.0333 ± 0.0018 (𝑀𝑔/𝑘𝑔), 0.0697 ± 0.0011; 0.1035 ± 0.0015 (𝑚𝑔/𝑘𝑔) and 1.008 ± 0.0035; 0.600 ± 0.002 (𝑚𝑔/𝑘𝑔) respectively. The mean concentration value of the two samples of both tilapia and catfish were found to be above WHO standard limit except for cadmium in tilapia which is below WHO standard limit.