LEVEL OF SOME SELECTED HEAVY METAL CONCENTRATIONS IN WATER, SEDIMENT AND FISH SAMPLES OF LAKE TINIKE, EASTERN HARARGHE ZONE, EASTERN ETHIOPIA

Abstract

A study was done to assess the level of some selected heavy metal concentrations in water, sediment and fish samples as well as to determine the physico-chemical parameters of water and sediment samples collected from Lake Tinike, during dry and wet seasons. To achieve those objectives, a laboratory based cross sectional study was conducted from January to June, 2017. Water, sediment and fish samples were collected from purposefully selected sites in three sampling sites during the dry and wet seasons. Analyses for heavy metals in fish, sediment and w ater samples were done using an Atomic Absorption Spectrophotometer (AAS). The physicochem ical parameters like temperature, pH, total dissolved solids (TDS) and conductivity were also determined in the present study. The results revealed that the overall mean values of copper (Cu), cadmium (Cd), lead (Pb) and manganese (Mn) in water samples of all sampling sites in dry and wet seasons were 0.96±0.02, 0.05±0.003, 0.13±0.07 and 1±0.01mg/L, respectively. The overall mean values of Cu, Cd, Pb and Mn levels observed in sediment samples of all sampling sites and both seasons were 2±0.041, 0.8±0.008, 1.7±0.1 and 1.22±0.1 mg/kg, respectively. Similarly, the overall mean values of Cu, Cd, Pb and Mn detected in fish samples of all sites and both dry and wet seasons were 2.78±0.034, 0.07±0.001, 1.72±0.02 and 3.46±0.08 mg/kg, respectively. This results showed that, the fish samples had highest mean value of Cu, Pb and Mn as compared with the mean value of water and sediment samples. But the lowest and medium mean values were recorded in water and sediment samples, respectively. From the selected heavy metals, Cd, Pb and Mn in water samples exceeded the maximum permissible limits of drinking water. In sediment samples, Cu, Cd and Mn concentrations were above the permissible limit except Pb. Unlike the Cd and Mn, the concentrations of Cu and Pb in fish samples were recorded above the permissible limit. These indicated that the most of analyzed heavy metal results in water, sediments and fish samples were from Lake Tinike had recorded levels above the international permissible limits. The findings of this study would have important information on the implications of public health with regard to heavy metal concentration in water and fish consumers of Tuji, Kura, Tinike and the surroundings.