Assessment of lead metal contamination of tap water used in Makerere University

Abstract

This study assessed the levels of lead metal contamination in tap water used at Makerere University, Uganda, to evaluate its safety for consumption. Given the severe health risks associated with lead exposure, particularly in institutional settings with aging infrastructure, this research aimed to quantify lead concentrations and compare the efficacy of colorimetric (dithizone method) and spectrophotometric (Atomic Absorption Spectrophotometry, AAS) analytical techniques. Water samples were collected from eight locations across the university, including halls of residence, laboratories, and staff quarters, and analyzed in duplicates. The colorimetric method failed to detect lead due to its limited sensitivity, whereas graphite furnace atomic absorption spectroscopy provided precise measurements of trace lead levels. Results revealed that all sampled locations had lead concentrations significantly below the World Health Organization (WHO) permissible limit of 10 µg/L, with the highest concentration recorded at 0.0319 µg/L in University Hall. Spatial variability in lead levels suggested localized influences, such as plumbing age or water stagnation, though all values remained within safe thresholds. The study underscores the superiority of graphite furnace atomic absorption spectroscopy for accurate lead quantification in water and highlights the need for routine monitoring, infrastructure audits, and public health education to mitigate potential risks. While the current lead levels pose no immediate health threat, the bioaccumulative nature of lead necessitates proactive measures to safeguard long-term water quality. These findings contribute to the broader discourse on water safety in institutional settings and provide a foundation for policy interventions aimed at ensuring sustainable access to clean drinking water.