Analyzing the Stabilization of Heavy Metals in Ash from Medical Waste Incinerators with XRF and ICP-OES Techniques   Inappropriate disposal of hazardous medical waste presents a major risk to human health and the environment due to the release of toxic heavy metals during combustion.  This study examines how well two analytical technique X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma optical emission spectroscopy (ICP-OES) identify and quantify the levels of heavy metals in ash residues from three local medical waste incinerators. Heavy metal concentrations, including Fe, Nd, Ce, Sn, Sb, Ir, Th, and Au, were found to be increased in the results, beyond permissible regulatory levels.  A solidification/stabilization (S/S) procedure employing regular Portland cement was used to reduce these concerns; cement ratio were7% and 25% by weight. Post-treatment analysis showed that XRF provided more consistent and reliable detection across all samples, with treatment efficiency ranging from 89% to 100%. In contrast, ICP-OES results varied significantly, with removal efficiencies between 5% and 100%. For several high-risk elements, the S/S method achieved complete immobilization. The findings suggest that the XRF method offers superior performance in monitoring the stabilization process due to its high sensitivity and precision. The cement-based S/S use the method demonstrated high effectiveness in reducing heavy metal mobility, making the treated ash suitable for safe disposal and potential reuse in construction applications such as roadways and civil infrastructure. These results underscore the importance of selecting appropriate analytical tools for waste assessment and highlight the potential of S/S as a sustainable solution for hazardous medical waste management.