Heavy Metal Contamination in Water, Sediment, and Fish from Lake Tinike, Eastern Ethiopia: Ecological and Public Health Implications

A study was conducted to assess concentrations of selected heavy metals in water, sediment, and fish, and to determine the physicochemical parameters of water and sediment from Lake Tinike during dry and wet seasons. A laboratory-based cross-sectional study was carried out between January and June 2017, with samples collected from three purposively selected sites. Heavy metals were analyzed using an Atomic Absorption Spectrophotometer (AAS), while temperature, pH, total dissolved solids (TDS), and conductivity were measured. The mean concentrations of copper (Cu), cadmium (Cd), lead (Pb), and manganese (Mn) in water were 0.96±0.02, 0.05±0.003, 0.13±0.07, and 1.00±0.01 mg/L, respectively; in sediments, 2.00±0.041, 0.80±0.008, 1.70±0.10, and 1.22±0.10 mg/kg; and in fish, 2.78±0.034, 0.07±0.001, 1.72±0.02, and 3.46±0.08 mg/kg. Fish samples showed the highest levels of Cu, Pb, and Mn compared to sediments and water, which recorded medium and lowest concentrations, respectively. Cd, Pb, and Mn in water exceeded the maximum permissible limits for drinking water, while Cu, Cd, and Mn in sediments were above permissible levels except for Pb. In fish, Cu and Pb exceeded permissible limits, whereas Cd and Mn remained within acceptable ranges. Overall, most heavy metal concentrations in Lake Tinike samples were above international safety standards, posing potential ecological risks and significant public health concerns for surrounding communities that rely on the lake for water and fish consumption. Therefore, continuous monitoring, strict regulation of pollutant discharges, and public awareness initiatives are strongly recommended to safeguard both environmental and human health in the region.