DETERMINATION OF HEAVY METAL CONCENTRATIONS IN FISH (Electrophorus electricus) FROM IBOM RIVER IN IKONO LOCAL GOVERNMENT AREA

Abstract

This research work was conducted to assess the concentration of five difference heavy metal concentrations in Electric eel (Electrophorus electricus), collected from Ibom River in Ikono Local Government Area of Akwa Ibom State, Nigeria, using Atomic Absorption Spectrophotometer (AAS) method. The five different heavy metals analyzed were Chromium (Cr), Cadmium (Cd), Lead (Pb), Copper (Cu) and Zinc (Zn). The results of the analysis shown that the concentrations of heavy metals in Electric eel were in their decreasing order Zn 3.144mg/kg ± 0.010 > Cu 2.125mg/kg ± 0.035 > Cr 0.504mg/kg ± 0.006 > Cd 0.196mg/kg ± 0.009 > Pb 0.027mg/kg ± 0.005 were detected. The concentration of heavy metals recorded in the fish sample also indicated a certain degree of bio-accumulation. The concentrations of all metals in the fish sample were below the National Aquatic Resources Research and Development Agency (NARRDA, 2015) recommended limits except copper (Cu) and chromium (Cr) which were higher than the recommended limits. The bio-accumulation factor of heavy metals such as copper (Cu) and chromium (Cr) in Electric eel (fish) are high beyond the tolerable level, which indicated that as far as these metals are concerned, the fish is unfit for human consumption, due to harmful effects of copper (Cu) to human body such as kidney damage, inhibit urine production and anemia cause by rupture of red blood cells (hemolytic anemia) which can cause death. Also, excess amount of chromium (Cr) can cause harmful effect to human system such as kidney damage, upper abnormal pain, nose irritation and damage according to Agency for Toxic Substances and Disease Registry (ATSDR, 2012). Consequently, close monitoring of metals pollution and the consumption of the Electric eel of Ibom River is recommended with a view to minimizing the risk of health of the population that depend on the river for water and fish supply.