Assessment of Heavy Metals in Water, Fish and Sediments from UKE Stream, Nasarawa State, Nigeria

The levels of lead, zinc, copper, iron, manganese, cadmium and mercury were determined in various body parts of two species of catfish; Clarias gariepinus and Synodontis schall, water and sediment samples from Uke stream using atomic absorption spectrophotometer (AAS) method. The results obtained showed that iron (Fe) had the highest concentration with average of 8.78 mg/g and 7.51 mg/l in sediment and water respectively followed by Zn with 4.79 mg/g (sediment) and 3.19 mg/l (water) while Cd had the lowest concentration of 0.035 mg/g and 0.023 mg/l in the sediment and water respectively. In the two fish species, zinc (0.17 – 3.25 mg/g) was the most highly concentrated in the various matrices while lead (0.011 – 0.031mg/g) was the lowest. Metal levels in the various body parts of the two species of fish studied were found to be more concentrated in either, the head, gills or the intestine. In both species zinc had the widest variability while lead was the least. The metal levels determined in water and sediment are all above the tolerable limits recommended by regulatory bodies which is an indication that this ecosystem is contaminated with heavy metals which would eventually end up in the food chain. The metals determined in various body parts of two species of catfish were below deleterious level; however there is the need for regular monitoring of the heavy metal load in this water body and the aquatic organisms in there because of the long term effects.