Determination of heavy metals (Cr, Cd, Pb, Zn, Mn and Cu) in pipeline drinking water using inductively coupled plasma optical emission spectroscopy (ICP-OES) The case of Negele kebele at Guangua town, West guji zone, oromiya regional state , Ethiopia

Abstract This study employs Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) to determine the concentrations of specific heavy metals in pipeline drinking water at Guangua Town in Negele Kebele. Six samples were collected using a random sampling method, with three samples combined for analysis. The samples were analyzed for the presence of heavy metals including chromium (Cr), cadmium (Cd), lead (Pb), zinc (Zn), manganese (Mn), and copper (Cu). The accuracy of the method was validated through spiking, yielding percentage recoveries between 87.4% to 99.5%, which are the acceptable range of 70% to 125%. The concentrations of Cd, Cu, and Cr (0.006 , 0.005 and 0.019)mg/l were found to be close the detection limit, while Pb, Zn, and Mn (0.069 , 0.120 and 0.017)mg/l respectively concentrations were measured. These values are assessed against the Maximum Admissible Limits (MAL) set by the WHO (2023) and Ethiopian health guidelines. The results indicated that while some metal concentrations remained within permissible limits, others exceeded recommended thresholds, posing potential health risks. Therefore, consumers are advised to seek alternative food sources to compensate for the reduced levels of Zn and Pb. Additionally, authorities are encouraged to enhance water quality to ensure safety and compliance with health standards.